Analyzing this opening I played I just played what I believe was a set of moves that gave me an overwhelming advantage (I exchanged 2 minor pieces for rook + 2 pawns + prevented castling + doubled pawns + exposed enemy king):

(I am playing Black, so flipping the board is recommended)

[FEN ""]
1. d3  e5 2. e3  Nc6 3. Bd2  d6 4. h3  Nf6 5. Nc3  b6 6. Qf3  Bb7 7. d4  Nxd4 8. Qxb7  Nxc2+ 9. Kd1  Nxa1 10. Qc6+  Nd7 11. Kc1  Be7 12. Kb1  Nb3 13. axb3  O-O

In the final position, one would think black is winning, but in fact engines say I am around -0.50, and I did lose the game. The opponent soon controlled my dark squared bishop after Nf3, and also I couldn't kick the queen away.

What do you think of this position? What color do you think will win more often using non-amateur strength?

In the immediate future Black has major light-square weaknesses and is susceptible to blockade (Nd5, Ba6). It's going to be difficult for Black to break out. Ideally Black would like to get his pawns onto light squares and free his bad bishop but this will be difficult to achieve.

White has an undeveloped kingside, doubled pawns, but easy development and his king is not particularly weak being on a light square. White's ridiculously advanced queen position is surprisingly secure.

I prefer White.


How do OTB games end up in databases? How do games of players that are not so well known, or not huge events end up in Chessbase and other databases? What are the different ways that games are cataloged?

If they are not playing on an electronic board in a televised event, are carbon copies being deposited in a box and someone is inputting all the moves? I have played in tournaments with many lesser known GMs and IMs but it hasn't appeared to be any obvious mechanism for how games might end up in one of the databases.

Here is a link to the FIDE record for a norm tournament where I was the chief arbiter. Two or three lines up from the bottom it says "PGN file" and next to it is a brownish icon. If you click on it you can see a list of all the games with the possibility to play through them in a PGN viewer or to download them.

Here is a link to a low level (Minor) tournament I played in a few weeks ago. Towards the bottom of the header it says "Games: There are 59 games available for download". Clicking on the link gives you options to download games by round or to download all the entered games for the tournament.

These games have been entered and uploaded by arbiters and their assistants (cue for you to say "Thank you, arbiters!"). Some of this work (norm events) is done because it is a FIDE requirement. Some of it (like the low level tournament I played in) is done out of the goodness of the arbiters' hearts.

Generally speaking if you enter a tournament and the scoresheets provided are single copy then your game won't end up in an online database and if it is a two-copy scoresheet then it will. The two-copy scoresheets cost more and a tournament organiser would not waste money on them unless the games were to be recorded and uploaded.

People who run websites that include all the games they can find have written bots which crawl the web (or at least select parts of it) looking for PGNs which they download and add to their collection for their website or database.


How do opening books in engine chess work? I thought opening books were just big compilations of opening moves that engines have access to, and they choose at random which move to play from the list of moves that the opening book says is good. However if this is correct, I don't see how videos like this make sense. How can an opening book "beat" another?

Am I understanding opening books wrong? What are they exactly, and how do they make an engine stronger (if they actually make the engine stronger)?

Your understanding is more or less correct, an opening book is a large collection of positions and what are the "book moves" in that position. I don't know if engines typically choose at random if there are multiple moves in the book for a given position or if they do something more complicated, but that doesn't matter much for your question.

  How can an opening book "beat" another?

It can contain better moves, and more of them, and they could even be better tailored to the specific opponent!

To figure out which is better, you let the same engine play against itself, with one side using one opening book and the other side the other. If you take care to have each book play white as often as black, you can see in the end which book had a higher score against the other book.

For instance, an opening book could contain a line somewhere that actually is not as good as the author thought at the time of putting it together, and the other book chooses to go for that position as the other side and it leads to a win for the engine.

Or one book is "done" after 15 moves after which the engine is on its own, but the other book still has several moves coming up after it on which the engine spent far more time on while creating the book than it could during the actual game.

Or the author of the opening book for engine A knows that engine B is worse at playing certain positions from the French, and he chooses to put moves into the book that causes A to go for those positions whenever it has the chance.

Or an opening book author spends days analyzing a certain position in an opening, and finally figures out that there is a way to force a good position for white there, and he adds it to the opening book. Engines with books that still allow that position to come up will have a bad time there.

And so on, opening books are in the end created by humans (with heavy use of engines) and the same arms race is going on there as between top human players.


How to become a rated player? Can someone explain to me what are the procedures involvd in getting a chess rating? If different countries have different procedures then how one can get an international chess rating in India?

You need to play against players who already have a FIDE rating in competitions which are themselves FIDE rated. The numbers keep changing but I think you need at least one draw out of 5 games against FIDE rated opposition. This doesn't have to be achieved in one competition but there is a time limit before your games expire, something like 2 years, but I don't know exactly.

I should add that FIDE have standard, rapid and blitz ratings and these don't mix. So, if you play 3 FIDE rated opponents in a standard time control competition and 2 in rapid or blitz that does not count as 5.

EDIT:
I've checked out what the FIDE site says:

  6.1 If an unrated player scores zero in his first tournament, his score and that of his opponents against him are disregarded.
  Otherwise, if an unrated player has played rated games, then this
  result is included in computing his overall rating.

  6.31 For an unrated player’s first performance to count, he must score at least 1/2 point.

  7.14 A rating for a player new to the list shall be published only if it meets the following criteria:

  7.14a If based on results obtained under 6.2 [round robin with min 4 rated players], a minimum of 5 games.

  7.14b If based on results obtained under 6.3 [swiss], a minimum of 5 games played against rated opponents.

  7.14c The condition of a minimum of 5 games need not be met in one tournament. Results from other tournaments played within consecutive
  rating periods totalling not more than 26 months, are pooled to obtain
  the initial rating.

7.14d
The rating is at least 1000.

7.14e
The rating is calculated using all his results as if they were played in one tournament (it is not published until he has played at least 5 games) by using all the rating data available.


Can I buy IBM DeepBlue? The IBM DeepBlue which is a chess computer that won against the one of the world's top chess players Kasparov was an IBM research project.

Can I buy this?

Thanks in advance.

I guess you have to ask IBM, but it's probably not for sale. Right now the custom made computer is on display at the Computer History Museum.


How does X-FEN (Chess960 FEN) differentiate from traditional FEN notation? I understand that a modified version of FEN notation is needed to properly record a Chess960 game.

I know that en passant is only slightly different, (an en passant possibility is only recorded if there are adjacent enemy pieces.)

Reading through the Wikipedia article on X-FEN, I don't understand how to record castling. I ask because I am in the middle of creating a chess app, and I want to store game states with FEN.

Can someone explain how castling is recorded in X-FEN notation? Thanks :D

Let's start at the beginning
To understand X-FEN for castling in Chess960, it helps if you first understand castling in Chess960. Castling rules are slightly different in Chess960, hence there comes a need for X-FEN. I believe it's the major source for your confusion.
Minor Note 1 X-FEN is used not just for Chess960 but for many other variants as well (Capablanca chess, Janus chess, Chess480, etc.)
Castling in Chess960
Castling in chess960 is done on two sides: the a-side and the h-side, analogous to queenside and kingside castling respectively. The final positions after castling are the same in Chess960 and in standard chess.
The terms a-side and h-side are used as the initial board configuration is randomized, and what is queenside in normal chess needn't be so in Chess960 (the same applies for kingside.).
Why FEN is insufficient for Chess960
FEN is sufficient for standard chess, as there are only two initial squares for the rooks, on the a-file and the h-file.If a rook from the kingside somehow gets to say, the c-file, there is no question of allowing queenside castling with it as it isn't on the right square. (More on this in an example.)
In chess960, the rooks have many possible initial squares. In the course of a game, both the rooks could end up on the same side of the king. Now, if FEN is used, there is no way of clearly knowing which rook has the castling rights (without knowing the initial position) as either could be occupying the legal square for castling. As a matter of fact, X-FEN assumes by default the outermost rook in such cases to have the castling rights, but that needn't be the case always.
An example to make my point clear

Standard Chess
If the above position occurred in a standard chess game, the FEN would simply be

rn2k1r1/ppp1pp1p/3p2p1/5bn1/P7/2N2B2/1PPPPP2/2BNK1RR w Kq - 4 11

This is because White can castle legally on the kingside, with the rook on the h-file. The rook on the g-file would play no role in castling, simply because that isn't on the legal square for kingside castling.
Likewise, Black can castle only on the queenside, hence the FEN has a q for the castling rights of Black. The rook on g8 is irrelevant.
Minor Note 2 Precise readers might point out that the number of moves and half-moves required to arrive at the position shown, in a normal chess game, might not tally with the values given in the FEN. That is quite possibly true, but I stuck to the value given for the Chess960 game (for the same position) on Wikipedia, for simplicity's sake.
Chess960
The situation changes if the game is Chess960, simply because the legal initial square for the white rook could be either g1 or h1. We cannot be sure without knowing the initial position. We cannot ascertain which rook has the kingside castling rights.
If the FEN given above was used here, it would confer the castling rights on the rook on the h-file, as the outermost rook is assumed to be the one with the castling rights, by default. It would also mean that Black can castle only on the a-side (queenside, in other words).
As a matter of fact, the initial position for this game was actually

rnbnkqrb/pppppppp/8/8/8/8/PPPPPPPP/RNBNKQRB w KQkq -

If you notice the bold R's, you'll see that the legal square for the white  kingside rook (the one involved in h-side castling) is actually g1, not h1. Similarly, the home square of the black 'kingside' rook is g8, not h8.
This means that using normal FEN not only confers the castling rights to the wrong white rook, it also fails to indicate the ability of Black to castle kingside. It's because normal FEN assumes the initial squares of the rooks to be on the a- and h-files only.
Hence, to avoid the ambiguity caused by normal FEN, X-FEN records the position as

rn2k1r1/ppp1pp1p/3p2p1/5bn1/P7/2N2B2/1PPPPP2/2BNK1RR w Gkq - 4 11

The G (in bold) shows that the castling rights on the kingside are with the rook on the g-file, not with that on the h-file. This is the inner rook. Similarly, it ensures that Black's castling rights on the kingside aren't ignored.
The queenside castling possibility for Black is recorded normally as there is no ambiguity.
Summary
Recording castling in Chess960 using X-FEN works as follows:

Just like normal FEN, if the two rooks are on the opposite sides of the king.

Still like normal FEN, if both rooks are on the same side of the king, with the outermost rook having the right to castle.

Using the letter (capital for White, small for Black) of the file of the rook permitted to castle, when both rooks are on the same side of the king, with the innermost rook having the right to castle. In the above example, G is used to indicate that the inner rook of White (on the g-file) has the right to castle.

Hope that's clear, feel free to ask if there's any confusion!
Note: Special case
In the unusual scenario of three or more rooks (due to underpromotion) being on the same side of the king, with the king yet to castle, there would be an outermost rook, an innermost rook and one or more rooks in between. In such a case, the outermost rook is treated the same way as above, and any other inner rook is identified by its file (depending on which has the right to castle).

For the curious, here's the PGN of the entire example game.
[Event "SmirfGUI Computerchess Game"] [Site "CHESSBOX"] [Date "2005.06.19"] [Time "10:22:29"] [Round "Test"] [White "White"] [Black "Black"] [Result "*"] [Annotator "R. Scharnagl"] [SetUp "1"] [FEN "rnbnkqrb/pppppppp/8/8/8/8/PPPPPPPP/RNBNKQRB w KQkq - 0 1"] 1. h4 g6 2. g3 Bf6 3. a4 Qh6 4. Ra3 Bxh4 5. gxh4 Qxh4 6. Qh3 Qxh3 7. Rxh3 Ne6 8. Bf3 d6 9. Nbc3 Ng5 10. Rhh1 Bf5 11. O-O *

Image and PGN courtesy Wikipedia


What are good chess tournaments to play in Europe as a USCF Class A + age 21+? I'm looking for a good European chess tournament to play that would be good for my age and playing strength. Perhaps even meet more chess player close to my age group. Any suggestions?

You can give a try to the monthly "First Saturday" round-robin tournaments in Budapest. (You probably have heard of it, it has been in existence for like 22 years.)
The city is nice, the venue is downtown, the local girls are beautiful, the majority of the players speak/understand English, maybe the only issue can be that your rating qualifies you for group "FM-A", where the opponents are rated between FIDE 1850 and 2100. But 9-11 games are guaranteed.


Why should black not capture the knight here? I played a game on lichess. (Link: http://en.lichess.org/n2hfBGYy#18) After the game I did a stockfish analysis of the game. This is the position:

[fen ""]
[Event "Rated game"]
[Site "http://lichess.org/n2hfBGYy"]
[Date "2015.03.09"]
[White "Kartikay"]
[Black "superca"]
[Result "0-1"]
[WhiteElo "1044"]
[BlackElo "1698"]
[PlyCount "56"]
[Variant "Standard"]
[TimeControl "300+6"]
[ECO "A42"]
[Opening "Sicilian Defense, Hyperaccelerated Fianchetto"]
[Annotator "lichess.org"]

1. e4 c5 2. Nf3 g6 3. d4 { Sicilian Defense, Hyperaccelerated Fianchetto } cxd4 4. Nxd4 Bg7 5. Nc3 Nc6 6. Nxc6 bxc6 7. Bc4 e6 8. O-O d5?! { (0.44 → 0.96) Inaccuracy. The best move was Qc7. } (8... Qc7 9. Bg5 Ne7 10. Re1 Rb8 11. Bb3 d6 12. Qd2 O-O 13. a3 Rd8 14. Rad1 Ba6 15. Bf4 Be5 16. Bxe5 dxe5) 9. exd5 cxd5 10. Bb5+? { (0.99 → -0.29) Mistake. The best move was Nxd5. } (10. Nxd5 Bb7 11. Bb5+ Kf8 12. Nf4 a6 13. Qxd8+ Rxd8 14. Be2 Bf6 15. Nd3 Kg7 16. Nc5 Bc6 17. Nxa6 Ne7 18. c3 Nd5 19. Bd2 Nc7) * {The rest of the game is not shown here}

I played 10. Bb5+ an stockfish labeled it as a mistake. Stockfish said that the best move was Nxd5. I was surprised by this, why should black not capture the knight in this position?

[fen "r1bqk1nr/p4pbp/4p1p1/3N4/2B5/8/PPP2PPP/R1BQ1RK1 b kq - 0 10"]

(Stockfish gives the evaluation +1.48 if black captures the knight.)

What comes to my mind (maybe someone can check with a computer):

After 10.Nxd5 ed 11.Bxd5 the rook is attacked and you have the motif of playing Bxf7+. The bishop cannot be taken because the king has to keep defending the queen. So after 11…Rb8 12.Bxf7 Ke7 you already have three pawns for the piece, i.e. material is equal and the black king has lost the right to castle and will come under attack. Possibly giving the exchange with 11…Be6 is better, but even then the intermediate check 12.Bb5 looks very nasty (After Bd7 there is always Re1+ as well and the maybe Bg5 ...).


Loss as black in 4.e3 English / rook ending [FEN ""]
[Date "6/10/2018"]
[Round "4"]
[White "Opponent"]
[Black "Me"]
[Result "1-0"]
[WhiteElo "2383"]
[BlackElo "1874"]

1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. e3 Be7 5. Qb3 O-O 6. Be2 d6 7. d3 Rb8 8. O-O Bg4 9. a3 Nd7 10. Qc2 f5 11. h3 Bxf3 12. Bxf3 Nf6 13. b4 Qd7 14. Bd2 g5 15. b5 Nd8 16. d4 Nf7 17. Rad1 g4 18. hxg4 Nxg4 19. Bxg4 fxg4 20. Ne4 Qf5 21. Rc1 exd4 22. exd4 Ng5 23. Nxg5 Bxg5 24. Qxf5 Rxf5 25. Bxg5 Rxg5 26. Rfe1 Rf8 27. Re7 Rf7 28. Re8+ Rf8 29. Rce1 Rg7 30. Kh2 h5 31. Kg3 Rgf7 32. Rxf8+ Kxf8 33. Re4 Rf6 34. a4 Kf7 35. a5 b6 36. a6 Rf5 37. Re2 Rf6 38. f3 gxf3 39. gxf3 Rf5 40. f4 Rf6 41. Rh2 Kg6 42. Kf3 Rf5 43. Ke4 Rf6 44. Rg2+ Kf7 45. Rh2 Kg6 46. Rh1 Re6+ 47. Kd5 Rf6 48. Rh4 Rf7 49. Kc6 Rh7 50. d5 Kf5 51. Kb7 c5+ 52. Kb8 Ke4 53. Ka8 Kf5 54. Rxh5+ Rxh5 55. Kxa7 Rh1 56. Kxb6 Ra1 57. Kb7 Kxf4 58. a7 Ke4 59. a8=Q Rxa8 60. Kxa8 1-0

My rating: 1874

Opponent's rating: 2383

I felt that I played strongly in this game but faltered due to a lack of understanding in the endgame. Any critique on the middlegame is also appreciated. Feel free to address any of these points or anything else that is important that I did not mention:

After 7...Rb8, my plan is to develop the bishop to g4 and eventually expand with f7-f5. Is this the right thinking? Perhaps my bishop doesn't belong on g4, or perhaps I could achieve my plan quicker without spending time on ...Rb8 and ...Bg4.
After 10...f5 11.h3 I am losing the bishop pair due to 11...Bh5 12.Nxe5!; was there a better way around this?
14...g5!? was what I felt was the only way forward. Would I be better off preparing this with something like ...Kh8 and ...Rg8?
After playing 17...g4, again perhaps I'm pulling the trigger too quickly.
Instead of 20...Qf5, should I consider 20...d5?
Maybe I could've played 21...Rbe8 and sat for a little longer before starting to liquidate this position.
For some odd reason I felt compelled to play 35...b6 in light of white eventually creating some sort of a pawn breakthrough, but perhaps this isn't a worry with rooks on the board? Keeping my original pawn formation could be important later.
My opponent said 39...Rg6+ was definitely drawing because the kings can't really go away from the f-pawn. Allowing 40.f4 may have been the critical mistake. After that I'm not sure the best defense against white's king march.
And I missed the 54.Rxh5+! trick in advance.

Also please no computer analysis unless something cannot be justified without it. Thanks!

Let me try to cover your bullet points:

After 7...Rb8, ...Bg4 idea:  First I don't see the connection of Bg4 with pushing your f-pawn.  Your pawns are on dark squares so trading your light square bishop is not a great idea either.  How about 8...h6 with the idea of 9...Be6 and 10...d5.
After 10...f5 11.h3 I am losing the bishop pair:  You didn't properly calculate your Bg4 idea.  What did you think was going to happen with Bg4?
14...g5!?: this is fine.  White floundered the last few moves so attacking is good.
A 17...g4:  I would strongly consider 17...e4!  You have 2 knights and no light square bishop so closing the center with a space gain and tempo looks correct.  You can follow with c6, or h5 and g4.
Instead of 20...Qf5, should I consider 20...d5?  I would definitely calculate d5, but why open the whole board for the battle when you have space by his king.  I like throwing pieces to the king-side.
Maybe  21...Rbe8:  21...exd4 is where you start going wrong with the idea of liquidating.  Why do you want to liquidate?  At this point you should be asking yourself "What does White want to do?"  The answer is liquidate! Nc3 is probably his next move. I'd be look at ...Bh4 here.
compelled to play 35...b6: First, lets go back to move 26 where you should have played 26...Kf7 and have no worries.  You can't let him double rooks on the open file for free.  Of course 35...b6 is horrible.


In the game of shogi, what is the meaning of "sabaki"? I'm reading the book Sabaki at a glance by Madoka Kitao. It's a very nice book with many good examples one can learn from.

The problem I have is that I am left with only an intuitive understanding of the word itself. There is a note by the translator:

  "Sabaku" or "sabaki" as an act in shogi has a nuance with the mixture of the following points.

  To resolve an awkward or problematic position of the own pieces into
  an acceptable outcome.
  To give the piece an opportunity to efficiently participate in the game or fulfill its task in a way even by sacrificing it.
  It usually involves light footwork, or a skillful and dynamic piece maneuver.
  It usually happens in the middlegame.

I find this a bit too general to make immediate sense. What is "sabaki", and what would be the corresponding concept in western chess?

I'm a Japanese native and have been a chess and Shogi player for a long time.
The Japanese word sabaki basically means proper handling of some complicated task, thus can have different meanings in different fields.
In my opinion, the closest chess term is a "freeing move/maneuver". For example, after 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 o-o 6.Nf3 Nbd7 7.Rc1 c6 8.Bd3, Black may play dxc4 9.Bxc4 Nd5 (Capablanca freeing maneuver). This looks similar to middlegame sabaki in Shogi to my eyes.


Analysis of Pawn Endgame from Amateur to IM I started reading the book "From Amateur to IM".  In one of the first chapters an analysis is given of Casablanca's Pawn Endgame.

[StartFlipped "0"]
[fen "6k1/7p/8/8/8/8/6PP/6K1 w - - 0 1"]

Now, the book starts by describing several building blocks for going about to win this position.  One of them (if black pushes his pawn to h6) is to reach the following position with Black to move and an then do an outflanking maneuver.

[StartFlipped "0"]
[fen "8/8/5k1p/8/5KPP/8/8/8 b - - 0 1"]

1...Ke6 2.Ke4 Kf6 3.Kd5 Ke7 4.Ke5 Kf7 5.Kf5 Kg7 6.Ke6 Kg6 ( 6...h5!? 7.g5 Kg6 ) 7.h5+ Kg7 8.Ke7 1-0

The line given in the book is printed in bold, but in move 6 the pawn h5 push seems to really kill any winning possibilities.  Am I overlooking something?  Is the analysis in the book flawed?

If indeed the analysis in the book turns out to be flawed, I would appreciate an alternative strategy to win Casablanca's pawn endgame when h7 is played.

White will be able to force the black King away and make progress.

Something like 8.Kd6 Kf7 9.Ke5 Kg6 10.Ke6 Kg7 11.Kf5 Kf7 12.g6+ Kg8 13.Kg5 Kg7 14.Kxh5


Is rotating a pawn so that it faces a different direction and then moves in that direction technically permitted according to the 2018 FIDE Laws? While browsing the Chess Stack Exchange and Puzzling Stack Exchange sites, I've come across several instances where people have found loopholes in the rules of chess, causing these loopholes to be patched out eventually. In fact, while reading through the current (since Jan 1 2018) FIDE Laws of Chess, I noticed the following paragraphs:

3.7.1 The pawn may move forward to the square immediately in front of it on the same file, provided that this square is unoccupied, or
3.7.2 on its first move the pawn may move as in 3.7.1 or alternatively it may advance two squares along the same file, provided that both squares are unoccupied, or
3.7.3 the pawn may move to a square occupied by an opponent’s piece diagonally in front of it on an adjacent file, capturing that piece.

Now I'm curious about the wording of these paragraphs, especially the phrase "in front of it". This "front" direction is not defined or mentioned anywhere in the Laws. Its usual meaning is "towards the rank furthest away from the pawn's initial location", but what if it weren't?
Suppose "front" is taken to mean the facing of the physical pawn (imagine figurine pieces with a clearly identifiable "front"). In that case, if a pawn is placed facing a different direction than usual, White could move a pawn to a lower rank or capture on a lower rank. Moving along the same rank is forbidden by the wording of 3.7.2.
Here are two examples I'm thinking of:
1.e4(facing e3) e5 2.e4e3
1.e4 d5 2.e5(facing d5) d4 3.e5xd4
In this case, it could even be technically permitted to rotate a pawn (changing what is "in front of it") using "j'adoube" before moving it.
Alternatively, the "front" direction could be defined as the direction the player is facing. However, in this case, Article 2 insufficiently defines how the chessboard is to be placed:

2.1 The chessboard is composed of an 8 x 8 grid of 64 equal squares alternately light (the ‘white’ squares) and dark (the ‘black’ squares).
The chessboard is placed between the players in such a way that the near corner square to the right of the player is white.
[...]
2.3 The initial position of the pieces on the chessboard is as follows: [depiction of standard positions]

It is not mentioned which pieces start closer to which player, so according to this interpretation it is technically not illegal to start with the white pieces on the side of the board closer to Black. "Front" would then mean that pawns could only move one step (assuming you get the pieces out of the way), but not promote afterwards (since the promotion rank is defined in paragraph 3.7.5.1 as "the rank furthest from its starting position"). Alternatively, a player could rotate the chessboard by 180° before moving.
I'm aware that all this is nitpicking the rules, of course that's not the intended way to play chess, I get that. So here's the question I'm actually interested in: Suppose that during a FIDE tournament, some player makes a move that is legal only by one of the above interpretations of the rules. How would this situation be resolved properly, considering Articles 11 and 12 of the Laws?

This sort of thing is what the Preface of the Laws of Chess is for:

  PREFACE

  The Laws of Chess cannot cover all possible situations that may arise
  during a game, nor can they regulate all administrative questions.
  Where cases are not precisely regulated by an Article of the Laws, it
  should be possible to reach a correct decision by studying analogous
  situations which are discussed  in  the  Laws. The  Laws  assume
  that  arbiters  have  the  necessary  competence,  sound  judgement
  and absolute objectivity. Too detailed a rule might deprive the
  arbiter of his freedom of judgement and thus prevent him from finding
  the solution to a problem dictated by fairness, logic and special
  factors.

  FIDE appeals to all chess players and federations to accept this view.

No, the laws don't define what the square in front of a pawn is. But arbiters have freedom of judgement to deal with that kind of omission from the rules.

And there is no way an arbiter will let you move a pawn in an illegal way during a FIDE tournament based on this argument.

It will just be treated as an illegal move (some bonus time for the opponent, have to make a legal move with the pawn if possible, and if it happens a second time the game is lost).


Is there a tool to automatically download a player's latest ICC games (history) into a pgn file? ICC stores your last 20 games, some of the clients also allow storing them into pgn files as you play. But if you use a client that does not support it, you then have to manually go and get each game out of history by hand into a pgn - one by one - at least in Blitzin. I want to get them all in one step into a pgn file as easily as possible.

Unfortunately, if you want to download them, you have to do them one at a time.  ICC does have a command "mailstored" which allows you to automatically have the games mailed to you in pgn or non-pgn format.  Here is more info on that:

ICC Help: mailstored
Command:  mailstored
Examples:  "mailstored darooha 8" -- This mails game #8 in darooha's history.
           "mailstored darooha POTZY" -- mails the adjourned game.
           "mailstored 5" -- mails game 5 in your current search list.
           "mailstored %5" -- mails game 5 in your personal library.

This command mails you the moves of the game you choose. You can email games from histories, libraries, database (search list), and adjourned games.

To automatically email all the games you play right after you play them, type "set automail 1".

"set mailformat 1" to get the game in PGN notation. "set mailformat 0" to get them in a non-PGN format that also includes the move times. Or "set mailformat 2" to get them in PGN with the clock times (the time remaining after each move) in comments.

There is a limit on the number of games you can "mailstore", due to the load the mailing puts on the ICC CPU. The limit is approximately 50 games in 12 hours. The games you get from "set automail 1" do not count towards the 50. There is no command to mail many games with a single command.

For Dasher and Blitzin, you can have every game you play automatically saved to a PGN file upon completion.

For Dasher:

http://www6.chessclub.com/helpcenter/Dasher/AutoSave.htm

For Blitzin:

Place a mark next to "Log my Games" on your Game menu. This will cause each completed game to be saved to a .pgn file on your hard drive.


If I analyze a move in a position to depth 25, then why am i only up to depth 15 immediately after playing the move? I'm using SCID with the latest Stockfish 7 on my Ubuntu PC. When I'm analyzing a position, I can see the depth counter on the left. After seeing that the move, Nf3 say, get to depth 25, I go to play the move. I would expect that when the engine is analyzing this new position, it would start at depth 25, but this is not the case. The engine needs to work up to there from the first observed depth considering the exponential increase in time-computing depth, around 14 or so.

Am I misinterpreting the depth counts or is there some technical reason as to why this is happening? One reason I thought, might be because if I hadn't chosen Nf3, and chose one of the worst moves, then there would be many missing branches due to pruning between candidate moves. This would mean evaluating the move using previous information would save little time since few variations have been examined.

I think the answer is that, although the engine has indeed calculated to depth 25, it has certainly not been able to store anywhere near the amount of the tree it examined during that search, no matter the memory allocated to the transposition table (hashtable). A lot of that tree (even of the pruned tree) is discarded as the depth-25 calculation continues, and so it pretty much has to be recreated after each move.

You may object that, almost certainly there must be a depth-24 value for the position after Nf3 stored in the hashtable left over from the previous depth-25 calculation. But that kind of proves the point -- the hashtable only stores a single value and a single "principle variation" leading to that value, not the whole depth-24 tree from which that principle variation was determined, by any means.


Problems with chess anxiety? I've been dealing with this for a while and the game can just sometimes be overwhelming. I really don't know how to calm myself and it might be effecting my play. I've been told maybe its because I don't do enough physical exercise but I'm quite fit so I know its definitely a psychological/mental issue. Maybe its my ego that can't take losing? After all I did put quite a considerable amount of effort and time in this game so it hurts to lose against someone you know who hasn't done the same even if its only once out of lets say a hundred games. Chess I think is probably bad for my health, I honestly start to feel hatred or anger towards my opponent sometimes such as if they play it like blitz chess or something. Maybe Its about time I just quit chess all together, that option has really slowly grown more appealing to be honest. Has anyone experienced something like this?

I really don't know how to calm myself and it might be effecting my play
Many people feel this way, e.g. becoming excited after winning material, or becoming upset when we slip from dynamic equality to a losing position.
To paraphrase IM Josh Waitzkin, who has a tutorial called The Psychology of Competition in the Chessmaster program:

Change your biochemistry to bring you back to the moment, e.g. take a break from the game, wash your face, or jog up a flight of stairs
Don't feel positively or negatively about previous positions. Stay objective and focus on just the position in front of you, rather than the preceding events. This is what a computer does

Chess I think is probably bad for my health
I'm not a doctor and I can't advise you on your health. If you feel that it is impacting your health, see your doctor. After all, your health is more important than playing chess.
Maybe its about time I just quit chess all together
Before you consider quitting chess, I would advise that you try a different, slower time control. I dislike blitz because I just don't have the time to play at the level that I would like to do.
Also, you may want to consider what it is that motivates you to play chess. Is it:

The competitive element?
The feeling of self improvement?
The artistry of the game?
Social engagement?
Something else?

If you don't feel motivated to play, then there is no need to force yourself into it.
Summary

What you feel is very common. Try to train yourself to remain objective when playing chess
If you feel the game is impacting your health, see a doctor
Reassess what you want from chess. If it isn't providing what you need, consider trying a different hobby


Longest *shortest available* fixed sequence of moves leading to checkmate? What is the longest fixed sequence of consecutive moves you can find in any legal position that

guarantees checkmating the opponent regardless of their responses (whether by forcing particular responses or otherwise), AND
is the shortest available fixed sequence of consecutive moves that checkmates the opponent in that position?

Example
Have a look at the position below:
[White "Checkmater"]
[Black "Checkmatee"]
[FEN "r5r1/1pq1k1Bp/3pb1p1/1p1P1p2/8/5N2/PP2QPPP/R3K2R w - - 1 18"]

1.Qxe6+ Kd8 2. Bf6+ Qe7 3. Qxe7+ Kc8 4. Rc1+ Kb8 5. Qc7+ Ka7 6. Bd4+ Ka6 7. Qb6#

In theory White has M5: 1.Qxe6+ Kd8 2.Bf6+ Qe7 3.Bxe7+ Ke8 (3...Kc7 4.Qxd6+ Kc8 5.Rc1#) 4.Bf6+ Kf8 5.Qe7#. But White's third move has to be different to achieve these mates: no one move works in both cases of 2...Ke8 and 2...Kc7. (For example, try 3.Bxd6+: with this, 2...Ke8 3.Bxd6+ comes with M2, and 2...Kc7 3.Bxd6+ comes with M5, yet neither of the two mates can be achieved by a fixed sequence of moves.)
However, White has the fixed sequence of moves shown above which guarantees checkmate (satisfying condition 1): 1.Qxe6+ Kd8 2.Bf6+ Qe7 3.Qxe7+ Kc8 4.Rc1+ Kb8 5.Qc7+ Ka7 6.Bd4+ Ka6 7.Qb6#. At 7 checkmater moves long this also appears to be the shortest fixed sequence available in the position above which guarantees checkmate (satisfying condition 2) - for example, we can create longer but equally forced sequences that also satisfy condition 1, such as trivially extending the mate above for example with 3.Qxe7+ Kc8 4.Rc1+ Kb8 5.Qc7+ Ka7 and now instead of 5.Bd4+, play e.g., 5.Qa5+ Kb8 6.Qc7+ Ka7, etc., and thereby add a few moves to lengthen the sequence while keeping it fixed and mate certain at the end.
Note that there is no necessity (in principle at least) for the opponent's moves to be forced. Condition 1 is satisfied as long as - no matter what Black chooses, if they have any choice - the same continuation for White (the checkmater) still results in checkmate.
Above I showed a position where the shortest fixed consecutive series of moves by White that guarantees checkmating Black is 7 moves long. (Not that I claim this as any kind of record.) I would like to see positions where there exists a sequence that satisfies these criteria and where that sequence is as long as possible - I'm guessing 8,9 White moves is small fry for some of the people here.

In other words, you wish for the record length for a completely dual-free sequence. Every White move must be absolutely unique to any possible by Black. Shorter, dualed mating sequences do not count.
To that end, I remembered a mate in 61 from this page on SuperProblem.ru (a Russian based chess problem site). It is also in the Die Schwalbe Chess Problem Database.
[Title "Bosko Miloseski, SuperProblem.ru 1/24/2020, Dedicated to the participants of TT-235, Mate In 61"]
[FEN "4Q3/1ppr4/br1k4/1p1p4/1PpP1p2/KBp2p2/2P2P2/8 w - - 0 1"]

1. Qe5+! Kc6 2. Qe6+ Rd6 3. Qe8+ Rd7 4. Ba2 Kd6 5. Qe5+ Kc6 6. Qe6+ Rd6 7. Qe8+ Rd7 8. Bb1 Kd6 9. Qe5+ Kc6 10. Qe6+ Rd6 11. Qe8+ Rd7 12. Ka2 Kd6 13. Qe5+ Kc6 14. Qe6+ Rd6 15. Qe8+ Rd7 16. Ka1 Kd6 17. Qe5+ Kc6 18. Qe6+ Rd6 19. Qe8+ Rd7 20. Ba2 Kd6 21. Qe5+ Kc6 22. Qe6+ Rd6 23. Qe8+ Rd7 24. Kb1 Kd6 25. Qe5+ Kc6 26. Qe6+ Rd6 27. Qe8+ Rd7 28. Kc1 Kd6 29. Qe5+ Kc6 30. Qe6+ Rd6 31. Qe8+ Rd7 32. Kd1 Kd6 33. Qe5+ Kc6 34. Qe6+ Rd6 35. Qe8+ Rd7 36. Ke1 Kd6 37. Qe5+ Kc6 38. Qe6+ Rd6 39. Qe8+ Rd7 40. Kf1 Kd6 41. Qe5+ Kc6 42. Qe6+ Rd6 43. Qe8+ Rd7 44. Kg1 Kd6 45. Qe5+ Kc6 46. Qe6+ Rd6 47. Qe8+ Rd7 48. Kh2 Kd6 49. Qe5+ Kc6 50. Qe6+ Rd6 51. Qe8+ Rd7 52. Kh3 Kd6 53. Qe5+ Kc6 54. Qe6+ Rd6 55. Qe8+ Rd7 56. Kg4 Kd6 57. Qe5+ Kc6 58. Qe6+ Rd6 59. Qe8+ Rd7 60. Kf5 Kd6 61. Qe6#

This works since Black basically has only one legal move for the entire mating sequence. There are no alternative lines that might spoil it with White dual mates and such.


What happens if you move your king on stalemate? Let's say the following happens during a blitz match:

White makes a move, resulting in stalemate
Black doesn't notice the stalemate and moves the king into an illegal position.

Usually illegal moves result in instant loss according to FIDE rules, but a stalemate results in instant draw. So, what's the outcome of the game? Draw or win for white?

This didn't happen in one of my matches, but
I've had some losses in the past because of illegal moves and I'm wondering what would happen in this case.

Just like checkmate, stalemate immediately ends the game. From the FIDE Laws of Chess, 5.2a:

  The game is drawn when the player to move has no legal move and his king is not in check. The game is said to end in ‘stalemate’. This immediately ends the game,
  provided that the move producing the stalemate position was legal.

This is not overridden by any rules in Appendix B, covering Blitz, so the situation you describe is a draw.


How to make a plan in an endgame? I need help on how to improve my thinking about endgames and how to produce a plan, what should I focus on and what should I not?

Planning in the endgame (this is what I seek on endgames)

Here is a breakdown of the different imbalances and what you should aim for:

Material (owning pieces of greater value than the opponent's);
Space (the annexation of territory on a chess board);
Superior Minor Piece (the interplay between Bishops and Knights);
Pawn Structure (a broad subject that encompasses doubled pawns,
isolated pawns, etc.);
Control of a key file or square (files and diagonals act as pathways
for your pieces, while squares act as outposts);
Lead in development (more force in a specific area of the board);
Initiative (dictating the tempo of a game).

If we are to use these things properly we must be able to break down our thinking in a way that allows us to dissect any particular position.

Here are the stages of my thinking technique that enables us to accomplish this:

Figure out the positive and negative imbalances for both sides;
Figure out the side of the board you wish to play on. You can only
play where a favorable imbalance or the possibility of creating a
favorable imbalance exists;
Don't calculate! Instead, dream up various fantasy positions, i.e.,
the positions you would most like to achieve;
Once you find a fantasy position that makes you happy, you must
figure out if you can reach it. If you find that your choice was not
possible to achieve, you must create another dream position easier
to achieve;
Only now you will look at the moves you wish to calculate (called
candidate moves). The candidate moves are all the moves that lead to
our dream position.


What is the better way to stop blundering all my games? I am on the road that starts from the "Beginner" stage, trying to leave this "town". I know and understand the rules, I also understand most of the "classic" tactics. I am able to reproduce some mating patterns (and to understand them I think).

But yet I have some difficulties to leave the "Beginner" town: I blunder often, mostly because I overlook some possible moves from the opponent (a little bit like if I was playing "alone").

It is very difficult for me to force myself to consider all the possible moves of the opponents. Please note that I play mostly on computer (either against the computer, or in live/online chess against other human beings).

So the question is: what is the better way to stop blundering all my games?

Should I forbid myself to "undo" my moves when I play against the computer? How should I read the board? Is there a standard way of forcing oneself to consider all the consequences of a move?

I am on the road that starts from the "Beginner" stage, trying to leave this "town". I know and understand the rules, I also understand most of the "classic" tactics. I am able to reproduce some mating patterns (and to understand them I think).

Based on your information I think I can safely assume that you would see those blunders if someone pointed them out. This is an important fact that helps me to recommend you the solution.

  It is very difficult for me to force myself to consider all the possible moves of the opponents.

You should not do that-it requires too much mental energy and wastes too much time.

  So the question is: what is the better way to stop blundering all my games?

Much better approach is to understand what your opponent's plan is and to search the best moves he can play to implement it. This requires the ability to understand the position that arose on the board, and a fair amount of objectivity. To achieve this start with the following actions:

Learn the basic moves and middle game themes/plans of your openings-I find Starting Out series to do a wonderful job, I use them myself too.
During play detach yourself from your emotions and use your knowledge of openings, tactics and middle game plans to evaluate quality of the opponents moves. Ask yourself questions like "Where does my opponent lead the attack?" , "What are my weaknesses?" , "Is this move played consistently-does it support opponents plan or is it a deviation?".
Tactical mastery greatly reduces blundering. Try to solve puzzles and try to improve this part of the game by constantly playing.

  Should I forbid myself to "undo" my moves when I play against the computer?

NO!!!

This is the best approach you can use-if you make a blunder just memorize that it is a bad move. Undo move and try to play a better one based on your own knowledge. If you fail to find satisfactory move, just consult books I have recommended or setup a position on your computer and order it to analyze. This will provide you much needed experience in playing that position, and at some point you will simply start to "feel" the good moves.

  How should I read the board?

Watch the entire board and look all the squares opponent's piece attacks ( the piece he played last with ). This is important, I have this flaw in my own game too and it creeps in because you do not "respect" opponents attack enough-believing that you have faster and stronger counter-attack or simply believing that your game is much better and he should resign instead prolonging.

  Is there a standard way of forcing oneself to consider all the consequences of a move?

Use the combination of all the above advices-watch all the squares his last playing piece attacks and try to understand what role that move plays in his overall plan. Knowing the basic moves of the opening will help you to survive 15+ moves, and knowing basic middle game plans will reduce your calculation time since you will be able to assume with great accuracy what is the point behind the last move your opponent played. Also, by knowing your opening and its middle game basics, you will find your counter moves much easier and much faster.

Tactical skill is also important here, and just by continuing to solve puzzles you will be able to find hidden threats faster, both for yourself and for your opponent-which will strengthen your evaluation accuracy.

Hopefully this will help, leave a comment if you need further help.

Best regards.


What happened to the Giuoco Pianissimo? Throughout a fairly long chess career, I have always regarded 4.d3 after 1.e4 e5, 2.Nf3 Nc6, 3.Bc4 Bc5 as a good beginner's move but not threatening, and I have felt sure that most strong players shared this opinion. Quite suddenly, 3.Bc4 and 4.d3 have become the choice of very many top players. In the recent Isle of Man tournament there were days when the top boards looked like a junior scholastic tournament (but with very few examples on the lower boards). I don't see a big difference between these games and typical 19th century games.

How did this happen? What has changed? Is there somebody out there who has been paying more attention than I have?

I agree with you. Players of all level play the Italian, and especially the 4. d3 line because they have read 2750+ players do so to avoid "drawing" (which is true at this level) lines aka Berlin Defense, as stated by Dag Oskar.

I see a bunch of 1500 rated players playing these lines, shuffling around trying to get something out of it, with no understanding of what is going on. I don't really see the point to be honest. This is true that the Italian has some bite if you know what you do, but the Giuco Piano/Pianissimo tend to generalize way too much. Personally, I tend to avoid it from move one 1...c5 ;) because I want to play chess. I'll play 1...e5 again when the Italian will be out of fashion.


What if both players always play the worst engine move? There are questions for the worst opening in chess and the worst opening in Chess960, but these only consider the very first move. I'm curious what a game would look like where white plays the worst opening, black plays the worst possible response, white plays the worst response to that, and so on until the game concludes. After every move, the evaluation bar would shift in the opposite player's favor as much as possible, making for quite a wild ride presumably.
I imagine it would be possible to generate a game like this using the API for Stockfish or another engine.
(The idea is vaguely reminiscent of antichess, but it's different, because (1) captures would not be forced and (2) players would be evaluating all moves using min-max like in regular chess, and then choosing the worst option, whereas in antichess both players are anticipating that the other player will play the most-losing move.)

You may find this game interesting: https://lichess.org/A9ZRnDcE.
Here Stockfish (black) is programmed to select the move leading to the most negative eval position. White is a human who is aiming to lose (i.e.: be checkmated). White is ultimately successful, which goes to show that really playing to be checkmated is a variant in its own right - we could call it Misère chess - and simply playing negative eval moves, even the most negative eval moves, doesn't make one a good player of Misère chess.
The reason for this is that chess engine positional evaluation assumes the 'optimal' responses (as far as the engine can tell) for subsequent plies. If we were to choose the move most likely to lead to our own checkmate ('selfmate') given  both sides on every subsequent move will be doing the same (as opposed to the assumption both sides are playing optimally for checkmate), then we would have a Misère chess engine. I am not sure what the technical challenges involved in developing such would be, but they are likely to be substantial given how far behind the state-of-the-art in selfmate solvers is compared to even the on-the-fly mating capabilities of a standard modern engines.
Lastly to answer your initial question, regarding engines playing the lowest eval moves on both sides assuming current eval metrics, have a look at this paper: http://tom7.org/chess/weak.pdf. The algorithm WorstFish does exactly what you ask. Its results against itself and even slightly less bad players are almost entirely draws. Even a much less bad algorithm like a random mover rarely actually beats WorstFish! So I'm afraid the answer may not be as dramatic as you'd hoped: players just keep offering and rejecting offers of material until it becomes impossible to do so, before swiftly trading down into a drawn endgame.


What are some chess tournaments around the world that have both Grandmasters and non-professionals players in the same section? I want to enter chess tournaments were there are titled players from more than one country and where non-titled players can compete in the same section.  Where can I find such open tournaments and what are the details?

I usually find my tournament in this online chess tournament calendar.

If you visit the homepage of a tournament you can often check who already registered and who is eligible to participate.

Another easy way to make sure your conditions are met is just checking the prizes. In Europe a thousand euro first prize usually means there are going to be GMs participating. If there are several thousand euro first prize you can be sure that there will be many GMs and other strong players from all over the world.


Advanced Pawn Structure books Hello fellow chess players. I've recently returned to the learning of this game, and as I forgot several ideas on deep mechanics, I read (again) "My System", from Nimzowitsch, and found it very useful, but I want to learn more about pawn structures and positional ideas. Would you recommend me some books? Thanks a lot. :)

I think the chess youtuber with the channel that goes by the name of Hanging Pawns has a lot of good explanations about structure/openings. I downloaded a very nice book about it, but I suspect that I'm not yet on the appropriate level to concentrate on it, the book is called: Chess Structures: A Grandmaster Guide - by Mauricio Flores Rios.


What does Stockfish NNUE mean for Stockfish? Apparently there was a major update to Stockfish recently such that it gained +50 elo (per regression tests). I'm told that the difference is coming from the new NNUE (efficiently updatable neural network) eval function. In other words Stockfish is now a hybrid engine utilizing AB search & NN eval.
Questions:

Is this picture correct?
If so, how is the NNUE being trained? Is it only being trained on Stockfish games, or does it also utilize games by other engines?
If NNUE is being trained on Stockfish games, does that mean Stockfish's original handwritten eval will continue to be tested and improved on? Or will Stockfish NNUE be trained on Stockfish NNUE games in the future (i.e. the handwritten eval is now obsolete and will not be developed anymore)?
Does this mean Stockfish's update process will now take longer? In the sense that for every new patch, a new NNUE would need to be trained, and then the new patch + new network plays against the old patch + old network?

Answers to your question:

Is this picture correct?

You got it exactly right. It's exactly that- ab search with NN eval.

If so, how is the NNUE being trained? Is it only being trained on Stockfish games, or does it also utilize games by other engines?

Basically, it's given a bunch of positions and the SF eval at a certain depth, and is trained from that data. I'm not sure where the positions come from but I believe SF self-play.

If NNUE is being trained on Stockfish games, does that mean Stockfish's original handwritten eval will continue to be tested and improved on? Or will Stockfish NNUE be trained on Stockfish NNUE games in the future (i.e. the handwritten eval is now obsolete and will not be developed anymore)?

Yeah, handwritten eval will continue to be worked on. It's also worth noting that SF (the one after the merge) technically uses its old eval in certain types of positions- sadly I can't go into more detail since it's constantly changing with new elo-gaining patches, but as I understand it, classical eval is meant to be used in "messier" positions, while NNUE is used in quieter positions.

Does this mean Stockfish's update process will now take longer? In the sense that for every new patch, a new NNUE would need to be trained, and then the new patch + new network plays against the old patch + old network?

Nope, patches should come at the same speed (currently they're coming at a much faster rate due to obvious improvements being all over, like, I  go to sleep, I wake up, already several patches gaining elo....). As I understand, there'd be no need for a new NNUE.


Confusion about Touch and move rule I accidentally touched my bishop and opponent's "Knight", while reaching for my queen during a game, almost simultaneously. Am I forced to take the opponent's piece?

FIDE Article 4.3:

  Except as provided in Article 4.2, if the player having the move
  touches on the chessboard, with the intention of moving or capturing:

  a. one or more of his own pieces, he must move the first piece touched
  that can be moved

  b. one or more of his opponent’s pieces, he must capture the first
  piece touched that can be captured

  c. one piece of each colour, he must capture the opponent’s piece with
  his piece or, if this is illegal, move or capture the first piece
  touched that can be moved or captured. If it is unclear whether the
  player’s own piece or his opponent’s was touched first, the player’s
  own piece shall be considered to have been touched before his
  opponent’s.

If a player touches a piece without the intention of moving or capturing (e.g. fingerslip), there is no touch move restriction.


Phone application for classical games I am looking for mobile phone website where I can download and replay games of Tal, Smyslov, Alekhine, Lasker etc.

Could anyone with help me with info?

You can download a PGN viewer for your phone platform, then search chessgames.com for your favorite players and their games for playback.  Having a PGN viewer installed is helpful also for sites like chessbase or chessvibes that sometimes link straight to the games file and not an online viewer.


King + Queen vs. King + Queen - is this a draw? Black and white both have one queen and the king. Is this game a draw?

The side to move first in KQ vs KQ wins in 41.75% of the positions. That's because the side to move first gets the first check, which is often decisive in these major-piece endgames - compare how many KQQ vs KQQ positions, which ostensibly have equal material, are won by the side to move first (83%).
Caveat: "positions" here refers to all legal positions, some of which might not be realistic in practical play.


Why doesn’t the computer like my odd queen trade? I played a game as Black some months ago on chess.com in which I made a rather amusing, in my opinion at the least, queen trade. I won the game in the end, but only after being a bastard and promoting to a bishop twice.

[Title "kassabian-Rewan Demontay, Friendly June U1200, chess.com, June 10-July 1, 2019"]
[FEN ""]
[startply "33"]

1. e4 e5 2. d4 exd4 3. Qxd4 Nc6 4. Qd1 d6 5. b3 Be6 6. Bb2 Nf6 7. Bxf6 Qxf6 8.  h4 Be7 9. Nd2 O-O-O 10. g3 d5 11. Rb1 dxe4 12. f4 exf3 13. Rh2 Bg4 14. Rf2 Bc5  15. Rxf3 Bxf3 16. Ngxf3 Rhe8+ 17. Be2 Qxf3 18. Nxf3 Rxd1+ 19. Kxd1 Nd4 20. Nxd4  Bxd4 21. Bg4+ Kd8 22. Kd2 Bf2 23. Rd1 Bxg3 24. Kc3+ Ke7 25. Rd3 Be5+ 26. Kc4 Kf6  27. b4 Re7 28. Rf3+ Kg6 29. Kd3 h5 30. Bf5+ Kh6 31. Be4 b6 32. a4 f6 33. Rf2 Bg3  34. Rg2 Bxh4 35. Rg6+ Kh7 36. Rxf6+ Kg8 37. Bd5+ Kh8 38. Rf8+ Kh7 39. Be4+ Kh6  40. c4 Bf6 41. Ra8 g5 42. Rxa7 g4 43. b5 g3 44. c5 h4 45. cxb6 cxb6 46. Ra6 Rd7+  47. Ke3 Bg5+ 48. Kf3 Rf7+ 49. Ke2 Rf2+ 50. Ke1 Bd2+ 51. Kd1 Ba5 52. Ra8 Kg5 53.  Rg8+ Kf4 54. Rf8+ Ke3 55. Rxf2 Kxf2 56. Bd5 g2 57. Bxg2 Kxg2 58. Ke2 h3 59. Kd3  h2 60. Ke4 h1=B 61. Ke5 Kf2 62. Kd6 Ke3 63. Kc7 Bd5 64. Kb8 Bb3 65. Ka7 Bxa4 66.  Ka6 Kd4 67. Kb7 Bxb5 68. Ka7 Kc5 69. Kb7 Be8 70. Ka6 Be1 71. Kb7 b5 72. Ka6 b4 73. Ka5 b3+ 74. Ka6 b2 75. Ka7 b1=B 76. Kb7 Bc6+ 77. Ka7 Kd6 78. Kb8 Kd7 79. Ka7 Bf2+ 80. Ka6 Bd3+ 81. Ka5 Be1+ 82. Kb6 Bb4 83. Ka7 Bcb5 84. Kb6 Kc8 85. Ka7 Bc5+ 86. Ka8 Be4#

The computer gives a question mark to my move ‘17... Qxf3?’. Why is this so? The only downside to it is that I lose an exchange, but on the other hand the game becomes more simplified and easier to play. Is the loss of an exchange the reason, or are there other factors at play?

Additionally, why doesn’t the engine suggest 36. Rg4+ to pick up Black’s dark sqaure bishop? And why is 36... Rex4 the best move versus Kg8 or Kh8?

Losing an exchange is itself enough to make the move weak.
You go from being up R+P for N, which is a winning advantage,
to up just one pawn with opposite color Bishops, which
could often be drawn.

The move is also weak because you let White off the hook:
you were on the attack against White's exposed King,
so the trade of Queens made the position "easier to play" --
for White.  Instead of giving up material
just to trade your active Qf6 for White's passive Qd1
(it has only one move!), try involving the in the attack
your Nc6 (your only piece not already aiming at the Ke1),
or trading it for one of White's defenders.
Either 17...Ne5 or 17...Nd4 should win quickly:

17 ... Ne5 actually threatens the Nf3: after Nxf3+, both defenders
(Nd2,Be2) will be pinned.  What's more, the Nf3 itself is "pinned"
in that if it moves (say 18 Nxe5) then 18 ... Qf2 is mate!
White has no real defense; if 18 Kf1 then simply Nxf3 19 Bxf3 Rxd2
20 Qxd2 Qxf3+ and mate.

17 ... Nd4 adds the threat against the Be2; now White can defend
for a move with 18 Nxd4, but 18 ... Qxd4 restores the threat Qf2#
and White might as well resign (19 Qc1 Qf2+ 20 Kd1 Qxe2#).

After 36 Rxf6+? Rxe4 simply wins a piece: if 37 Kxe4 then Black takes on f6,
and if the Rf6 moves then Rxb4.  The alternatives "Kg8 or Kh8"
are not equivalent: 36 ... Kh8?? would have allowed 37 Rf8#!


Are there any gambits where I HAVE to decline? I know popular openings like the Queen's Gambit can be accepted with an initiative for white. Is there any gambit where accepting it would lead to a forced mate for the player that accepted it?

While it's not generally given as part of the explicit definition, the term "gambit" usually refers to an offer of material that can be accepted. If it can't be accepted, then it's a trap.
You can look through chess traps and see that many of them involve apparently giving up material.


Does the King's Indian Attack need the e5 pawn push to attack on the kingside? So from what I understand, a kingside attack can be started as long as the centre is closed.
I very recently started looking into the King's Indian Attack as an opening for white against the French and e6 Sicilians, but since I don't see many of either of those at the 1500 level on chess.com, I have only been able to try it out this one game.
Draws are very rare at my level but I just didn't know what to do by move 29 with my attacking chances completely gone and I guess neither did my opponent.
This is the game:
[Event "Live Chess"]
[FEN ""]
[Site "Chess.com"]
[Date "2021.04.06"]
[Round "-"]
[White "Me"]
[Black "Black"]
[Result "1/2-1/2"]
[CurrentPosition "r3r3/1bp3p1/1pn2p1k/p3pPpP/3pP1P1/P2P1BN1/1PP2K1R/7R b - -"]
[Timezone "UTC"]
[ECO "B00"]
[UTCDate "2021.04.06"]
[UTCTime "07:50:38"]
[WhiteElo "1506"]
[BlackElo "1443"]
[TimeControl "600"]
[Termination "Game drawn by agreement"]
[StartTime "07:50:38"]
[EndDate "2021.04.06"]
[EndTime "07:59:52"]

1. e4 Nc6 2. Nf3 e6 3. d3 d6 4. g3 Nf6 5. Bg2 Be7 6. O-O O-O 7. Re1 e5 8. Nbd2
Re8 9. h4 h6 10. Nf1 Bf8 11. Ne3 d5 12. Nh2 d4 13. Nef1 Ne7 14. f4 Nc6 15. f5 b6
16. g4 Nh7 17. Nf3 Be7 18. h5 Ng5 19. Bd2 Bb7 20. Qc1 Nxf3+ 21. Bxf3 Bg5 22. Ng3
Bxd2 23. Qxd2 Qg5 24. Qxg5 hxg5 25. Kf2 Kh7 26. a3 a5 27. Rh1 Kh6 28. Rh2 f6 29.
Rah1 1/2-1/2

So is the reason this was so terrible because I missed some great continuation, or does the attack just not work when I don't have a pawn on e5, since I started reading King's Indian Attack Move by Move by Neil McDonald and he puts quite a bit of emphasis on it. So if I commit to the KIA with 3.d3 and my opponent plays 3...d6, not allowing any e5 push, I should just open up the position and be left with a slightly worse opening?
I felt like my worst blunder was basically just creating an outpost for the black knight on g5 but even before that I didn't seem to be getting anywhere. Could anyone help me understand why this went so terribly and how I should know for next time that a kingside attack isn't a good idea?

It's not the KIA at fault (in fact we saw here a color-reversed KID) but you both
lacked when it comes to positional play.

In the end position, Black is far better. He can act the standard queenside pawnroller while you don't have the slightest attacking counterplay, and a horribly bad bishop.
But since so much material has been traded, Black probably didn't have the nerve to press on. (I would have, but then, I tend to win all endgames :-) Specifically, c4 is his only decent plan and you can hope to throw off the bishop.
Specifically, what went wrong was that you were "forced" to h5, after that all breakthroughs go through the window. Given that you stand so bad after that, I had played g5 nevertheless and at least got some open lines for the pawn.
You could have avoided to be "forced" by carefully preparing the attack: king to f2 and place a dozen rooks behind your pawn roller. Shall he argue with that. (Likewise, Black should have uncompromisingly rolled on the queenside. In KID, you must queen a few pawns and sacrifice the queens against the material that wants to mate you ;-)
I'm not even sure if f5 wasn't a bit early.
So, get the "Kmoch" (argueably, a bit ancient - the new "Shankland" is also nice) and learn about pawn play (especially levers). Get the "Vukovic" (likewise ancient) to learn how to attack a castled position, especially when to storm with pawns and when to attack with pieces. The good news is: Positional play will come automatically to you the more you learn and the more pattern you encounter. Practice.


Why are there 64 squares on a chessboard? My question is, why not 36, 49, 81 or some other square number? Do any historical sources point to how and why chess came to be played on 64 squares in particular? Has it always been so?

Nothing is stopping you from playing chess in a 4x4, 6x6 or 9x9 board. In ancient times people have tried such approaches.

To answer why 64 squares, I have to answer a bit mathematically. Let me start with this:

  [Chess, in] its early form in the 6th century was known as chaturaṅga, which translates as "four divisions (of the military)": infantry, cavalry, elephantry, and chariotry.

It says that chaturanga means 'game of squares' and it also mentions 4 divisions of military, where 1 division = 8 pieces (4 pawns + 4 main pieces). So 4x4 = 16 pieces each side. This also means, all in all, a total of 32 pieces in the board (8 in each row).

For 32 pieces to be fully mobile on the board, 36 squares would be too congested and not possible; 49 squares would be still too congested; 64 sure makes sense, and is also the perfect square of 8.


Is this tactics puzzle flawed? While solving puzzles on ChessTempo, I came across this puzzle:

[FEN "8/8/1p6/p1p3p1/P1P1B1K1/1P2kP2/5n2/8 w - - 9 1"]

1. Kf5

I played the intended correct answer,

[FEN "8/8/1p6/p1p3p1/P1P1B1K1/1P2kP2/5n2/8 w - - 9 1"]

1. Kf5 g4 2. fxg4 Nxe4

My question now, is this final position drawn, thus invalidating the puzzle?

I tried some lines but they all seemed to draw. Example:

[FEN "8/8/1p6/p1p3p1/P1P1B1K1/1P2kP2/5n2/8 w - - 9 1"]

1. Kf5 g4 2. fxg4 Nxe4 3. Ke5 Kd3 4. Kd5 Nf6+
5. Kc6 Kc2 6. Kxb6 Kxb3 7. g5 Ne4 8. Kxa5 Kxc4 {Tablebase draw} 1/2-1/2

Yes this seems to be a drawn endgame, most variations actually end up in a queen vs queen+knight situation which is generally a drawn endgame (one example below). But that doesn't mean the puzzle is flawed because as far as I know chesstempo puzzles are just about finding the best moves a priori, thus not always about a winning line. Good tactics trainers (such as chesstempo, lichess...) usually only say which side is to move, and the objective of the puzzle is actually part of the puzzle itself (that is, whether one is to play to mate, play to win material, or play to draw etc.)

In this particular position black has to come up with the best moves in order to hold the game it seems.

 [title "One possible continuation, 1/2-1/2"]
 [fen "8/8/1p6/p1p3p1/P1P1B1K1/1P2kP2/5n2/8 w - - 0 1"]

 1. Kf5 g4 2. fxg4 Nxe4 3. Ke5 Kd3 4. Kd5 Ng5 5. Kc6 Kc3 6. Kxb6 Kb4 7. Kc6 Nf7 8. Kb6 Ng5 9. Kc6 Kxb3 10. Kxc5 Kxa4 11. Kd6 Kb4 12. c5 Ne4+ 13. Ke5 Nxc5 14. g5 a4 15. g6 a3 16. g7 a2 17. g8=Q a1=Q+ 18. Kf5 Qf1+ 19. Kg6 Qg2+ 20. Kh7


Adventures from the ODCL - How To Play The Endgame? Well the league restarted after the Christmas break this week and here's much of my latest effort with a couple of questions afterwards - I haven't shown the whole game for reasons that I hope will become clear. For background I'm rated 139 ECF (~1750 ELO) and my opponent is 156 (~1870 ELO) and the time control is 90 minutes each for all moves, though time was not a factor in this game.

[Event "League"]
[Site "UK"]
[Date "2016.01.20"]
[White "Ian Bush"]
[Black "A.N.Other"]
[WhiteElo "1750"]
[BlackElo "1870"]
[Result "*"]
[FEN ""]

1.e4 c5 2.d4 cxd4 3.c3 Nc6 4.Nf3 d3 5.Bxd3 d6 6.h3 g6 7.Be3 Bg7 8.Qd2 Qc7
9.O-O h5 10.c4 Be6 11.Nc3 a6 12.Nd5 Bxd5 13.cxd5 Ne5 14.Nxe5 Bxe5 15.f4
Bg7 16.Rac1 Qd7 17.Qc2 Nf6 18.f5 gxf5 19.Rxf5 h4 20.Qf2 Rc8 21.Rf1 Bh6 22.
Bxh6 Rxh6 23.e5 dxe5 24.Rxe5 Qd6 25.Qf4 Qb6+ 26.Kh1 Qxb2 27.d6 e6 28.Rxe6+
fxe6 29.Qxh6 Kd7 30.Qxf6 Qxf6 31.Rxf6 Kxd6 *

So

1) What do you think of my play so far? I'm relatively pleased, my only major disappointment is due mainly to blood lust (Rooks don't go backwards!!) I didn't see 28 Re2 which wins, but comments are appreciated

2) End games are my weakness and I ended up drawing this one. How should white go about things from the final position? What principles should I be applying?

End games are my weakness and I ended up drawing this one. How should
  white go about things from the final position? What principles should
  I be applying?

The key features in the final position are:

1) You are a bishop for a pawn up

2) He has more weaknesses than you - 3 pawn islands to your 2

3) His king is much more active. It is ideally placed for action in the centre of the board while yours is stuck in the corner. This plus his passed e pawn are big pluses for him.

4) There aren't many pawns left. If they all come off it will be a draw.

Your aims should be, going from general to specific:

1) Play actively with your pieces to attack his pawns rather than passively defend if you can

2) Activate your king. His pawn on h4 is a big problem. If he can keep it and get his rook to the second rank then your king, your second most powerful piece, will be a spectator.

3) Avoid pawn exchanges.

4) Win the h4 pawn (I don't think he can stop you)

5) Blockade or win the e pawn

6) Queen either your g or h pawn

Without putting it through an engine I would suggest something like:

32 ... Rh6 - he isn't going to be able to save the h pawn

Rd8 (he wants to push his passed pawn) Rxh4
e5 Bd5 (blockading the e pawn and eyeing up the b pawn)
b6 (b5 would lose the a pawn after Rh6+) Rg4 (releasing the h pawn to run)

Push the h pawn, put your rook behind it on h4, move your king to where it is needed most. Not necessarily all in that order.


Does Stockfish NNUE have contempt implemented? Per title. As I understand contempt, it's a setting in the eval function that adds a bonus for material remaining on the board. This makes the engine favor positions with more material (i.e. more complex, i.e. more scope to outplay the opponent). It is meant to make the engine avoid quick draws against inferior opposition.
Stockfish recently implemented NNUE eval, and I am unsure if NNUE eval can include contempt. If yes, how does it work? The description above doesn't seem to work anymore.

I'm not sure if you understanding of contempt is right, but in any case; I just compiled SF12 and it seems you don't have two versions of SF (the standard and the NNUE) but you can set your SF12 to behave standard or NNUE. In the configuration screen for SF12 you can enable NNUE, and also the contempt value.
So the short answer to your question is yes, SF12-NNUE has contempt implemented.


How do I get my FIDE percentile? How do I get the percentile rating?

This is the rank:

World (all players):    97112
World (active players): 45540

How many players are there in the world that are members of FIDE?

According to this question on quora.com, there are ~486,000 players as of January 2015.  (They reference a FIDE rating list here.)  Not an exact number, but most likely close enough for percentile purposes.

If you're not sure how to calculate a percentile rating, I found this question, which gives the following formula:

R = P / 100 (N + 1)

... where R represents the rank order of the score, P represents the percentile rank, and N represents the number of scores.


What are the possible results of a game? What is the range of possible results of a chess game?

I am asking this question, because I am developing an XML schema for recording chess games; sort of like an XML version of PGN, and I need a way to classify and record the game result.

The list of possible results that I came up with:

Win for white, by virtue of checkmate.
Win for white because black resigns.
Win for white by arbiter declaration.
Same as 1, 2 and 3, but for black.
Draw by reason of stalemate.
Draw by agreement of players.
Draw by declaration of arbiter.
Draw by claim of Three-fold repetition by white
Draw by claim of score-sheet written intention of Three-fold repetition by white
Draw by claim of 50 move rule by white
Draw by claim of score-sheet written intention of 50 move rule by white
Same as reasons 9 .. 11, but claim made by black
Game abandoned
Game adjourned

Is there any thing wrong with my list? Is it exhaustive? Are there other ways a game can end?

In addition to the things mentioned, at least two categories are missing in my opinion. The first one is "A oversteps time when B does not have enough mating material" and the second one is "A didn't arrive at the chessboard in time and B won".

Let's structure it a bit better so we make sure we don't miss anything. I have marked some of them with an asterisk to indicate that the cases exist but may well be handled by other categories.

Game scheduled to start.
(*) Game postponed. (If we have game in progress, we should have this one as well. Otherwise, put it under 1.)
Game finished without any moves played. This is important because whether a game will be rated or not depends on whether every player has played at least one move.

a) White arrived at the chessboard after default time. (-:+, § 6.7)

b) Both players arrived at the chessboard after default time. (-:- or 0:0)
Game in progress. (As mentioned in the other answer.)
(*) Game adjourned. (Appendix E. I think there are still events in the world where this happens, but none of these are actually serious enough to warrant this category. I guess FIDE will remove it over the course of the next ten years. However, it is possible on some internet servers (e. g. FICS), so don't put it too far away if you want to cater for that as well. If not, it should be 4.)
Game finished according to the Basic Rules of Play. (The "basic rules of play" are the first five articles of the Laws of Chess; the other articles are called "Competition rules".)

a) White wins by checkmate. (1:0, § 5.1a)

b) Black resigns. (1:0, § 5.1b)

c) (*) Game drawn by stalemate. (½:½, § 5.2a) This is a special case of d), but, undoubtedly, it is a very special case and deserves its own category.

d) Game drawn by dead position. (½:½, § 5.2b)

e) Game drawn by mutual agreement. (½:½, § 5.2c)
Game finished by the clock.

a) (*) Black's flag falls during the n-th time control and the player has not completed the required number of moves. (§ 6.4 in conjunction with § 6.3a) You may merge a) and b), but then, unless you add time indicators, the two cases are indistinguishable. (1:0)

b) Black's flag falls during the last time control. (1:0)

c) (standard) Both flags have fallen and it is not clear which one fell first. (§ 6.11) (½:½, § 6.11b)

d) (*) (standard) In the last time period, both flags have fallen but Black's flag fell first. (Can be put under a) or b)) (1:0)

e) (rapid and blitz) Both flags have fallen. (½:½, Appendix A, § 4c)

f) White's flag falls, but Black has not enough mating material. Draw. Note that this is not necessarily 6d. (e. g. KB v KQ is always at least drawn for black). (You actually need this for a), b), and d) separately. See note below the list.) (0:½)
Game finished according to article nine of the laws of chess. (The drawn game.)

a) Drawn by claim of three-fold repetition by white. (½:½, § 9.2b)

b) Drawn by claim of score-sheet written intention of three-fold repetition by white. (½:½, § 9.2a)

c) (*) Drawn because X claimed draw by three-fold repetition and implicit draw offer was accepted by Y. Could be regarded as a normal draw offer. (½:½, § 9.2 in conjunction with § 9.1.b.3)

d) Drawn by claim of 50 move rule by white. (½:½, § 9.3b)

e) Drawn by claim of score-sheet written intention of 50 move rule by white.  (½:½, § 9.3a)

f) (*) Drawn because X claimed draw by 50 move rule and implicit draw offer was accepted by Y. Could be regarded as a normal draw offer. (½:½, § 9.2 in conjunction with § 9.1.b.3)

g) Drawn by article 9.6a (the same position has appeared, as in 9.2b, for at least five consecutive alternate moves by each player, new rules!) (½:½)

h) Drawn by article 9.6b (any consecutive series of 75 moves have been completed by each player without the movement of any pawn and without any capture, new rules!) (½:½)
Game results in a quickplay finish. (appendix G, only in standard and rapidplay without increment) Maybe add an indicator where the increment time mode starts if appendix G4 is applied. In those two minutes, all other things mentioned here may well happen (checkmate, illegal moves, whatever).

a) Arbiter declares game drawn immediately. (½:½)

b) Arbiter awards extra two minutes and declares game drawn afterwards. (½:½)

d) (in games without the supervision of an arbiter) An external arbiter decides according to G6.
Game finished by decision of an arbiter because of a breach of rules of one player.

a) (standard games) Game lost because of two irregular moves by Black. (1:0, § 7.5b).

b) (standard games) Like a), but White does not have enough winning material (½:0, § 7.5b).

c) (*) (old rules, standard and rapidplay) Game lost because of three irregular moves by Black. (1:0) (It is very unlikely these cases have been recorded for past tournaments.)

d) (*) (old rules, standard and rapidplay) Like c), but White does not have enough winning material. (½:0) (It is very unlikely these cases have been recorded for past tournaments.)

e) (rapidplay and blitz) An incorrect move by Black is oberserved by the arbiter or correctly claimed by White. (1:0)

f) (rapidplay and blitz) Like e), but White does not have enough winning material. (½:0)

g) (blitz) The arbiter observes both kings being in check or an unfinished pawn promotion and the position is still on the board after one move. (½:½, Appendix A, §4a.)

h) Black brings a mobile phone and/or other electronic means of communication in the playing venue (1:0, note that White wins even with insufficient material!).

i) Game finished by decision of an arbiter because of misconduct by Black. (1:0, § 12.9 decision)
Game finished by decision of an arbiter because both players persistently refuse to comply with the laws of chess. Note that both players lose in this case. (0:0, Maybe this should be 10l))
(*) Game finished because of an irregularity at the start of the game. Now, I hope a game at a level worth recording will never be replayed according to § 7.2 (wrong initial placement of pieces). Additionally, semantically, there will still only be one game, so this should not be an end-of-game marker.
(*) Result to be decided.
(*) Game abandoned.
(*) Result unknown. (e. g. notation incomplete)

Another note: maybe one should have an insufficient material marker. Then you can simplify a couple of the above cases.

In the case of a team event, for example, you need two different results to represent the game properly: For example, here in Germany, if two players sit in the wrong places, one of the games will be declared lost even after the game has finished. All the cases where this can happen are in a team context, though, so it should be possible to implement this in a different way. Recent development of electronic cheating means this is very much a possibility: the game where the player has been found to be cheating will certainly be declared lost for him. However, it might be decided that for the competition, all games will be declared lost, but they still count towards the rating (although even this is a corner case).

Yes, tournament chess can be complicated.


An Aggressive Response (for black) against the closed sicilian? I am look for an aggressive response to the closed sicilian (1. e4 c5 2. Nc3 ...) in which black has strong attacking and tactical chances against white. Most of the variations I have seen result in black playing semi-positional plans on the queenside and center while white pummels black's king on the kingside.

Thank you in advance!

It's difficult to recommend an tactical line against the Closed Sicilian as White is attempting to avoid this sort play by keeping the center relatively closed/semi-open. I wouldn't characterize the play as Black playing purely positionally on the queenside and White "pummeling" black on the kingside - there are a variety of plans for both sides in the resulting middlegames. Black's expansion on one side of the board can be just as effective if not more so than White's attack on the king. An aggressive approach isn't limited to tactical play. I can recommend an approach that may make this concept more evident.

Against 1. e4 c5 2. Nc3, I have played 2...a6 in the past. Black's idea is quite simple - as he knows he's going to be playing on the queenside anyway, he decides to expand there before developing any of his kingside pieces. He usually follows up with moves like b5, Bb7, e6, and d5. This is certainly an aggressive reply to the Closed Sicilian, and can be defined as a positional one as well.


Why do GMs repeat moves instead of offering a draw? Watching recaps of the 2021 Candidates Tournaments, so many games end in consecutive repeating moves. I have a general impression that lots of top level games are drawn by repeating moves. Why do the grandmasters do this instead of offering a draw?

A repetition giving the opponent the opportunity to claim a draw is a de facto draw offer but not a de jure draw offer.
What does that mean? Well the "de facto" part means that in practice it has the same effect as a formal draw offer while the "de jure" part means that legally it is not a formal draw offer.
Psychologically it makes a subtle difference but practically it makes an important difference. The difference is the legal aspect. Why is this important?
According to article 11.5 of the FIDE Laws of Chess:

11.5 It is forbidden to distract or annoy the opponent in any manner whatsoever. This includes unreasonable claims, unreasonable offers of a draw or the introduction of a source of noise into the playing area.

Normally arbiters interpret this to mean repeated draw offers in a small number of moves. That is why you are instructed to notate your game as follows in Appendix C.12 -

C.12 The offer of a draw shall be marked as (=).

Repeating the position does not constitute a formal draw offer and so cannot be part of a claim of disturbance due to repeated draw offers.

What do you think the psychological difference is?

When you ask for a draw you are a supplicant. It's like you are asking for a favour. "Will you please give me a draw?"
When you repeat the position you are saying something completely different which is why in some positions the experts advise you to repeat once (so no possible draw offer) to demonstrate dominance, let the other player know who is the boss.
If you are a much lower rated player and you repeat twice in a forcing situation you are effectively saying "What ya gone do, punk? Repeat and give me the draw? Or deviate, play a bad move and give me a chance to win?"
I have won several games with that exact tactic. It's surprising when it works but some players have more ego than common sense. It's like their response is something like "No way am I accepting a draw against you. I'm so much better than you that I can beat you from a losing position". I have to admit I've been on the opposite side too. I've played a bad move rather than accept the draw and I've paid the price.


Developing the king before developing most of your pieces I saw this opening for the first time and was amazed by the position of the white king.
[FEN "?"]
[startply "21"]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. h4 h6 5. g4 Bd7 6. h5 e6 7. f4 c5 8. c3 Nc6 9. Nf3 Qb6 10. Kf2 O-O-O 11. Kg3

In this position, white made one knight move, two king moves, and no moves with the other pieces. Usually, we should castle early and hide the king in a safe corner. In this opening, white does the opposite by moving his king to g3 in the opening stage before developing most of their pieces. Is it really a good idea? Are there any other openings that you develop your king early in the game?

Don't try this at home. ;-)

First of all, a simple LiChess search gives this is B12 Caro-Kann Defense: Advance Variation, Tal Variation, i.e. it has even a name and is legit.
Second, 8 games listed, with IMs playing it, so it's still rare.
Third, standard Black move is Kb8. He doesn't even try to immediately throw everything except the kitchen sink at the white king!
And that is because the king is rather safe there. Usually you now would try the can opener g6 or f6, but it's not so easy as the king side of Black is underdeveloped and White can keep the relevant files closed. Black can't simply pile up major force, and already Steinitz said you need a force plus to storm the defense.
This is caused by the large space advantage of White at the kingside.
A concrete advantage of wK on g3 is that it does something useful (protecting g4) and avoids something annoying (tactics on e1, pins on g1...).
Note that the center is totally barricaded, otherwise it would be suicide.
Summing up, yes, in this concrete position (modern chess is hyperconcrete) it might be a good idea.

Concerning your last question (are there other variants?), this could be easily answered by a search in a Megabase. Steinitz Gambit of course comes to mind immediately.


Is there a common list of steps to analyse/annotate one's game? What is the best way to annotate one's game to derive the most instructive value out of it? In the search for critical positions - do you start from the beginning, or from the end (last move)? When do you consult a computer engine or computer database? Has any coach ever come up with a comprehensive guideline describing how to do this?

As Andrew points out in a comment, the subject of your post overlaps substantially with an earlier one, whose answers address the general mechanics of analyzing one's own games, and would probably be of use to you. I'd like to address just one small part of your question that doesn't overlap:

  In the search for critical positions - do you start from the beginning, or from the end (last move)?

Now whether a position in a game is "critical" or not isn't some objective feature of the position itself, but is rather a function of the position and the player who faces it. What I mean is: many a position in which you or I would say that we have a critical decision to make, Capablanca or Fischer might recognize it as trivial, and in other positions where we might blindly think there's nothing important to consider, players like them might say instead that there are deep considerations to be made.

So I don't think you need to be going through your game after the fact (forward, backward or any other way) trying to identify what the critical junctures were. You know what positions you considered critical when you were playing the game (when you agonized over choosing between two moves, when you spent a looooong time thinking, etc.), and those are critical points where self-analysis can be especially beneficial.

One habit you could get into is making a note of such moments on your scoresheet while you're playing (circle the move, make an X, whatever). Then not too long after the game, try to record as much of what your thought process was at those points. Later on you can look at what you were thinking during the game in a fresh light, and try to find improvements to your in-game mental analysis. Speaking to another part of your question: checking yourself with an engine is a good idea, but you should try to catch your own mistakes first, and only then let Stockfish or whatever show you all kinds of things you never considered or noticed.


During the 1984-1985 Karpov-Kasparov match, what was Karpov's initial weight? When discussing whether chess is a sport, I have often used that Karpov lost a reported 22 pounds (10 kg.) during the match as a point to show that chess can be physical. While 22 pounds is significant, I think it is even more significant because Karpov was a man with a very slight stature, meaning it was a much higher percentage of his total weight than if he had been a 250-pound man, but nowhere have I ever been able to find what his initial weight was.

Does anyone know Karpov's initial weight at the start of that match, or even his final weight, which would also tell us that information?

Here is one such story.

That's a lot, if validated. Karpov was rather slight at the time, something around 60kg or less, so that represents something under 20% of his body weight.

And actually, that's consistent with other facts, given that was a 50+ game match. Fabiano Caruana says he can drop around 10% of his body weight during a difficult tournament. (Said to an ESPN reporter.) Robert Sapolsky, a Stanford researcher, has measured some players at burning 6000 calories per day in a tournament.

Another unverified data point is Rustam Kasimdzhanov losing 17 pounds at the 2004 championship.

A lot was made of this recently, made "sexy" because Magnus Carlson sought the advice of Olympic trainers for his physical conditioning, but it's not a new discovery. Petrosian would also drop a lot of weight during the championship match cycle, and other champions like Botvinnik and Spassky made getting in physical condition an important part of their match preparation.

ESPN, NPR ("The Chess Grandmaster's Diet"), Men's Health, seems like every magazine got in on it last year.

I don't have anything verifiable on the Karpov bit, but the other work I've seen, taken with the comment from Caruana, means I'll accept it as true until someone can disprove it. It's been verified to happen to players other than Karpov, so why not him?


Should Black avoid the Two Knights Defense because of the Fried Liver Attack? It seems like the Fried Liver Attack is too much for black to handle, so it seems it is best to avoid the Two Knights Defense as Black.  An example of the Fried Liver Attack is below and Black just seems lost.  Is there something Black can do?

[FEN ""]
1. e4 e5
2. Nf3 Nc6
3. Bc4 Nf6
4. Ng5 d5
5. exd5 Nxd5
6. Nxf7 Kxf7
7. Qf3+ Ke6
8. Nc3  Ncb4
9. a3   Nc2+
10. Kd1  Nxa1
11. Nxd5 Kd7
12. Re1  c6
13. Qf5+ Kd6
14. Qxe5+ Kc5
15. Nc7 Kb6
16. Nxa8#

In Two Knights defense black doesn't have to play 5...Nxd5?! The main line is 5...Na5, where black sacrifices a pawn, but gets active play for compensation. The game could continue like this:

[FEN ""]
1. e4 e5
2. Nf3 Nc6
3. Bc4 Nf6
4. Ng5 d5
5. exd5 Na5
6. Bb5+ c6
7. dxc6 bxc6
8. Be2 h6
9. Nf3 e4
10. Ne5 Bd6
11. d4 exd3
12. Nxd3

Besides 5...Na5, Black also has 5...Nd4 and 5...b5.

A very interesting continuation is the Traxler attack (4...Bc5!?):

[FEN "r1bqk2r/pppp1ppp/2n2n2/2b1p1N1/2B1P3/8/PPPP1PPP/RNBQK2R w KQkq - 6 5"]

Black does not defend the f7-square, and it first might look like a blunder, since 5.Nxf7 leads to a fork. However black has plenty of attacking resources after 5...Bxf2. Therefore, white usually plays 5.Bxf7, black is down a pawn, and loses castling ability, but has some compensation due to semi-opened file and piece activity.


My question is about inconsistencies in Stockfish 7 outputs I have the Stockfish 7 engine loaded. I was playing through a variation of the Ruy Lopez [Open Berlin Defense], up to move 15,  using SFish. I let the engine run to a search depth of 25, and selected the best move. A short time later, I played the same sequence of moves and, at move 10, the suggested move and subsequent line of play had changed. On the first analysis, it suggested 10.Nc3-e2, and on the second run through, it came up with 10.Nc3-e4, and the followup line was, of course, completly different. So, why the difference between the two runs? And if the engine analysis is going to change from one day to the next, how can we know for sure what the objectively 'best' move is in any given line of play?

Many expert chess engine users (such as correspondence chess masters) advocate using more than one engine to analyze a position, because each has strengths and weaknesses.

Generally, Stockfish is considered strongest in positions with tactical elements, while Komodo is biased toward positional / strategic strengths.  Neither is a broad-spectrum solution.

As other responders have indicated, there's a lot of squishiness in the output of engines when there aren't any forcing lines, or transpositions are possible and undifferentiated.  Engines do a fair amount of pruning, which saves computation but introduces problems with "horizon". The horizon is the depth of moves the engine will look at a variation that leads to a disadvantage. Such a variation may have a redeeming comeback move at the end, but may be just long enough that the engine gives up analyzing the line before it reaches the comeback move, because it's over the horizon.

On its way to a "final" evaluation, the engine is essentially approximating.  That is, it evaluates the position, adds a few more moves and looks at the position, evaluates for the "best" move based on those, shifts to the next position, adds a few more hypothetical moves and evaluates, shifts, and so on.

At any one particular instant, the engine may be just about to shift from one evaluation of the position to another, even while the depth you're specifying is being reached.  If you terminate the analysis manually (i.e. pick a move and make it, or just hit the Stop button), you may get a different "best" move recommendation in one millisecond, and another one a millisecond later, even at the so-called maximum depth.

The best way to ensure consistency is to run the engine by itself in analysis mode using software such as Fritz.  The engine will evaluate the actual moves of a game (or an opening variation) offering improvements. The computation behind the improvements will be strictly limited by depth or time, as you specify.  If you let the engine terminate the search at each position, you should get consistent (deterministic) results. Unfortunately, although it will annotate the improved variation at each position, this approach involves the engine resetting its analysis with each move/position of the move score that is analyzed.  It won't move from improvement to improvement to improvement, leaving the game behind.

To get that kind of result, you need an engine tournament.  Give two identical engines a starting position (such as the Berlin or Moscow Variations of the Ruy Lopez) that you want to improve from, set their limits as discussed, and let them duke it out. Play at least a dozen games, and see if anything shakes out.  Two cautions:

This is time-consuming (but at least it's not your time), and
As you go further and further from known theory, the less likely that you'll ever see that position in an actual game played by anyone other than these engines, for the reasons discussed above.

BTW: As far as I know (and my research supports this), non-deterministic algorithms are not used in Stockfish or any other major engine.  The reasons for this are self-evident - if you're looking for a solution to a deterministic problem, you use a deterministic approach.  Stochastic approaches are only better in stochastic problem domains, or where a deterministic model is unavailable or problematic in itself.

As far as analysis depth goes, there's a point of diminishing returns that's determined by what you're trying to accomplish.

In different types of positions, the evaluation function of any engine will tend to stabilize at different points.  For one type of position, there will be no noticeable difference in the evaluation or the recommended "best" move after about 20 ply.  In another, you may need to hit 26 or 28 ply for the move to stop changing, and the evaluation function to stabilize at a terminal value to 2 significant digits (e.g. 1.87, instead of 1.86 or 1.88).

Clearly, if your goal is the perfect move / best evaluation accuracy, then if you can only choose one depth/time parameter limit, instead of a stability limit / sensitivity threshold, then you need one large enough to accommodate the most positions where the evaluation continues to be unstable to greater depth/for longer analysis time.  You need to aim high.

But there's a tradeoff.

In an actual game, as the game proceeds, the probability increases exponentially that one or both (human) players will play a non-optimal move.  Since the engine only calculates optimal moves, this means that in quiet positions (and in some complex tactical ones) the engine's choice of a move and the actual move played will almost always diverge, even if only slightly. It will also do so surprisingly frequently, often as many as a dozen times in a game even between GM's. This is, in fact, one of the indicators that TD's use to figure out whether a player at a tournament is getting outside help from an engine.

Because of this, if you're comparing a variation that an engine analyzes with a line that humans might actually play, the longer the variation, the more likely it is that the tail of the variation will only match the humans' moves when there is a forcing line.  In fact, unless the line is forcing, a fair amount of the time not even the opponent's first reply will match the engine's expected optimal reply.

The more unclear or quiet the position, the shorter the useful tail of an analyzed variation will be, even if the opponent replies with the expected move.

So, if you're analyzing a murky or quiet position or opening, and you're curious to know whether an engine could possibly play a line better, then have at it. But if you want to know if it's possible to find a single winning line given the replies that the opponent would actually end up playing, the real odds start to look like a craps game as the variation gets longer.

That said, there are ways to optimize how you use the calculation time as you analyze a game or an opening variation.

As @GeorgeJempty indicated, you can get much better results at 35 ply (ply are half-moves; 12 ply is 6 moves for each side) than you will at 25.  However, I use Stockfish on a Quad AMD at 2.9 GHz, and the positions where I need to go even 26 ply deep to find a hidden winning move that were missed at 25 ply are very few and far between (something on the order of 1 in 1,000).  For me, that's simply not worth the extra compute time it takes to find it.  What's more, the resulting improvement is almost certainly going to be negligible, because the probability that the opponent would have made the corresponding replies shrinks to zero, and the resulting end position would never appear.

In other words, the longer the move sequence, the greater the probability that any analysis will be overtaken by events.  This is one reason that even Grandmasters rarely calculate beyond 12 ply (except in endgames), and often only calculate to 4 or 6, relying on positional intuition instead.

As for how much of a difference ply depth makes at extreme depths, I have some background in the problem.  When I'm screening games for analysis targets (by this I mean trawling through large sets of them to find ones that had interesting highlights suggesting they're worth deeper analysis), I use just 23 ply. My configuration can get through about 10 games an hour at that clip, so I can process about 750 every night.  Once I find these, I then reset the depth to 25, and rerun the analysis on those selected games.

Obviously this approach would only make sense if I'd tested it, and I have. I've run a few experiments to test the merits of different depths, and the settings I use turn out to be optimal for the compute time I'm willing to allocate.  Only about 1 in 50 games turns out to have an interesting feature that shows up at 25 ply but gets missed at 23.  Clearly, that suggests that some of the games I screened out using 23 ply would also have shown such elusive features if they'd screened in instead, and subsequently been processed at 25 ply.  That's just the opportunity cost of the rate at which I choose to process games, and for my purposes, there's so much low-hanging fruit I don't really need to go climbing trees.

I would definitely take advantage of every CPU on your PC's chip, though. Most of the world's PC's computational power is incredibly underutilized.  On my configuration, at 1 CPU Stockfish does about 1K positions / sec, while at 4 CPU's, it runs over 4K positions / sec.  That quadrupling of the rate really tells when you're data mining, as I am.

To reiterate, I would also turn to Komodo for analyzing openings and quiet/murky positions as a comparative tool, and you should find that with one of the two engines the evaluations stabilize tolerably soon, at around 22-23 ply for most positions.