How to determine objectively if a move is passive or aggressive? I'm doing research about how different conditions or situations affect the decision making process in chess. For example if the opponent's ELO ranking affects the average time used for every move. In the example, both variables are numerical and easy to obtain. However I struggle when it comes to define if a move is more passive or aggressive (specially after the opening theory).
I noticed that, independently of playing style, there are some external factors that make us play more actively (aggressively, taking more risk) or passively (defensively, taking less risk). I read some articles that say it depends on the current position and the analyzer "strength" to determine with certainty, but that is too subjective for my purposes. There must be some some objective cues to help me.
I was thinking about the mobility (as in how many moves the player or the specific piece have after the last move) or/and if it is making or stopping a threat. Are there other cues or methods I could use to define if a move is passive or aggressive?
Is there software where I can analyze a complete game and give me this kind of output? Perhaps not if the movement was aggressive, but maybe if it is making a threat or reaching more mobility than before?
I also know that some software like Chessmaster, uses AI "personalities" and some make passive or aggressive moves as their traits. Can someone explain how the software chooses a move that may not be optimal but a passive one?

Let me answer your questions precisely and technically:

Q: I also know that some softwares like chessmaster...?

Nobody knows for sure because Chessmaster is closed source. Fortunately, it's not hard to replicate Chessmaster personalities. There're several ways to do it:

Define different piece-square-table (PST) for each personality
Define different tuning parameters for each personality
Scale the attacking parameters and/or defending parameters with a constant
Give an appropriate Contempt value

It takes some work to create a new personality, but it should be just minor changes to a working chess engine.

The Stockfish engine had an UCI option for optimizating attacking and defending parameters. This was done by scaling the evaluation score accordingly. For example, if you scaled your own king safety score by a positive constant greater than 1, the engine would be more defensive.

Q: How to determine if a move is aggregative or defensive?

Tony, Brian and others gave good suggestions, but their suggestions are for human players and too abstract for a computer. If you want a computer to tell you whether a move is aggressive or defensive, you may need:

Null move
Monte-Carlo tree search

Null-move is simple and it's been implemented in various chess softwares. The idea is simple - if the move doesn't threaten anything, it should not be an aggressive move.

Monte-Carlo tree search goes even further. You can use it to determine the distribution of your payoff. If a move is aggressive, the margin error should be smaller. If a move is defensive, the margin error should be bigger.


What is a good flexible opening for beginner with white? After I learned the Sicilian, I started to love to play as black, while before it my win rate with white was bigger than black (as expected due to white first move advantage). When I learned Sicilian exists, I started to win a lot as black (also in my low level of play I rarely see Sicilian used against me...)

I don't bother learning all Sicilian variations, I just move the C pawn first, and 'go with the flow' as needed, and with experience learn some of the more unusual moves (like moving pawns or knights in counter-intuitive ways after I notice in analysis why they were good idea, and then I learn later that it is a named opening).

How I do that as white? Right now all I do is spam Wayward queen, that sucks, but seemly other players suck more and lose to it anyway, the problem is that Wayward Queen attack is entirely a gamble, if other player sucks, I win, if other player is good, I lose.

I want some better white opening I can rely on as beginner, like I do with Sicilian for black.

I know there is another question about white openings, but that question talks about lots of openings, I want ONE flexible opening I can rely upon and learn its variants as I play, like it happened to me with Sicilian.

From your question it seems to me that you should focus on learning general opening principles (control the center, develop pieces, don't move the same piece twice, castle...), study tactics and learn how to develop a plan. These will be useful in all kind of situations you encounter during a game and if you follow them you will end up playing an "official" opening naturally.

Studying openings is not useful for beginners because:

your opponents will rarely play the moves you learned
without knowing some general ideas you will basically only end up memorizing moves without understanding the ideas behind them (which is particularly useful if your opponent makes a worse move)
generally, opening knowledge only has a very small effect on the level of play and only becomes relevant at higher playing strengths, let's say from Elo 2000 or so

If you are happy with the Sicilian, by all means continue playing it, but be aware that this is among the most complicated chess openings out there and you are far away from understanding it.

As for what to play with white, I suggest to first figure out what kind of player you are, or what kind of positions (e.g. open/tactical, closed/positional...) you like. For instance what do you like particularly about the Sicilian?


Mate in One the Missing King The post "A mysterious mate in one" made me think of one of my last problems which is also a Mate-in-One with no black King:
    [Title "White to move and mate in one"]
    [FEN "1B1NB2K/P2RN3/8/1R6/1P5P/4P2Q/1PP2PP1/8 w KQkq - 0 1"]

All the white pieces are there but none of the black ones.
White (at the bottom) to move.
The position is legal, except that the Black King (and the Black King only) is not displayed. Find it - there is but one place.
Mate in one.

Your post is perfectly fine here, my friend. Chess problems and puzzles are on-topic here, and we do need more. All kinds of all sorts are welcome. We just need to bring them here!
I think that out of the 14 open squares on the board, only:

 placing the Black king on both a6 works!

This is because placement on the squares:

 a1, a2, a8, a4, b1, c1, c4, d1, d2, e1, e2,  f1, f6, f8, g1, and h6 all result in an illegal position. This is due to the fact that Black either has no last legal move if it is White's turn, or it would've been impossible for the Black king to get around the current White pawn structure. Thus, they are not options at all. This explains the "retrograde-analysis" tag.

Therefore, remaining the square works:

 with the solution checkmate being 1. Rd6#.


clock simultaneous exhibition In a clock simultaneous exhibition, would the exhibitor normally be given extra time to compensate for his/her walking time from board to board? The question was prompted by a scene in a movie (the "Lewis" mystery series) where the exhibitor would come to each board with the opponent's move already having been made and the exhibitor's clock running, make her move and then hit the clock and move on.  Although I realize there's a skill discrepancy, it would still seem to be a distinct disadvantage to the exhibitor otherwise, particularly in a large exhibition.  I have never seen or participated in a clock "simul" myself, which must be relatively rare.

The exhibitor usually gets more time. Not really to compensate for the time walking from board to board takes, but because he potentially has all of the clocks running at the same time!

The most famous clock simultaneous exhibitions were the ones in which Kasparov took on national teams, including those of the Czech Republic and Israel. According to this old Chessbase article, Kasparov had three hours for 50 moves and the Czech GMs two and a half hours per 50 moves, with half an hour added after 50 moves (he won this 5.5-2.5 over two days).

Usually the difference is larger, but I can't find a source.


Need help spotting whats wrong? Although I would prefer just figuring this out on my own I feel like I need a stronger or more knowledgeable player to help me out here. I keep seeing a lot of my losses are when I'm up in material, low on time and in the endgame. I just don't understand why this pattern keeps reoccurring. Although it may seem obvious that my endgame skills are the problem it just doesn't feel like that is all there is to it. Here I'll try post a couple of games as an example. I also can't seem to add annotation unfortunately which means it'll be harder to explain some of the silly errors I made. These loses always tend to be the most painful and cause me to sometimes even consider quitting all together.

I play as black in this game. Also note I was low on time in all these games (not saying as an excuse for losing)

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. d4 Nf6 c4 e6 a3 c5 e3 d5 Nf3 Nc6 Nc3 Be7 dxc5 Bxc5 b4 Be7 Bb2 O-O Be2 dxc4 Bxc4 b6 O-O Bb7 Qe2 a5 Rfd1 Qb8 b5 Na7 Na4 Nc8 Be5 Qa7 Bc7 Bxf3 Qxf3 Qxc7 Qxa8 Qxc4 Rdc1 Qxa4 Rxc8 Qxb5 Rac1 g6 h3 Kg7 Rxf8 Bxf8 Rc7 Qb1+ Kh2 Bd6+ g3 Bxc7 Qb7 Bd6 Qc6 Bxa3 g4 b5 g5 Ne4 Kg2 Nxg5 Qc3+ f6 Qxa3 Qe4+ Kf1 Nxh3 Qe7+ Kh6 Qxf6 Qf5 Qh4+ Qh5 Qf6 e5 Qf8+ Kg5 Qe7+ Kf5 Qd7+ Ke4 Qc6+ Kf5 Qd7+ Kg5 Qe7+ Kg4 Qd7+ Qf5 Qd1+ Qf3 Qd7+ Kh5 Qxh7+ Kg5 Qe7+ Kh6 Qh4+ Qh5 Qe7 b4 Qf8+ Kg5 Qe7+ Kg4 Qd7+ Qf5 Qd1+

Lost on time, I'll show one more even though I've got way too many examples of games such as these haha.

Playing white this game

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. e4 c6 Nf3 d5 Nc3 d4 Ne2 c5 c3 d3 Nf4 c4 Qa4+ Nc6 Qxc4 e5 Nxd3 f6 Nc5 Qd6 Nb3 Be6 Qd3 Qc7 Qc2 Bd6 d4 Bf7 Bb5 a6 16. Bxc6+ bxc6 17. Be3 Ne7 18. dxe5 fxe5 19. Nfd2 O-O Bc5 Rfd8 O-O-O a5 Bxd6 Rxd6 Nf3 Rxd1+ 24. Rxd1 h6 25. Kb1 Rd8 26. Rxd8+ Qxd8 27. Nxe5 Be8 28. Nd4 c5 29. Ndf3 a4 30. Nd3 Qc7 31. b3 a3 32. h3 Qa7 33. Nd2 Bh5 34. f3 Bf7 35. Nc4 Bxc4 36. bxc4 Nc6 37. Qd2 Na5 38. Ne5 Qb8+ 39. Kc1 Qxe5 40. Qd8+ Kh7 41. Qxa5 Qf4+ 42. Kc2 Qe3 43. Qxa3 Qf2+ 44. Kb3 Qe3 45. Qb2 Qd3 46. a4 Qd1+ 47. Ka3 Qd6 48. Qb5 Qe5 49. Kb3 Qd6 50. a5 Qd1+ 51. Ka3 Qa1+ 52. Kb3 Qb1+ 53. Ka4 Qa2#

some obvious mistakes here like one of the many was me trying to trade dark squared bishops when his one is absolutely terrible, I regretted that choice during the game immediately

Also just remembering that my nerves tend to play up sometimes or I get quite emotional during play which I'm confident effects the ability to focus or think clearly. Although I try to work on this problem sometimes it feels like it can't be helped and everything just becomes somewhat chaotic in my mind. Maybe its my ego or my strong desire to win or not lose that is causing this, I'm not entirely sure. Honestly all these games look to me like I shouldn't be playing this bad and its not showing my real skill but that is really only what I feel about it and in reality I did play those games and there is no excuse and I guess I have to take responsibility and I deserved to lose.

Here are my observations:

Both games are long. The average game lasts about 40 moves. No wonder you ran out of time!
I can see you know the principle that when you are ahead in material, trade down. However, both games involved your king being chased around by the queen. You are not trading the right pieces
You don't need to be up that much material to win a technical game

Advice:

Learn to play more efficient chess. I'm guessing it took you some time to figure out all the branches in the tactical analysis

I feel that you are trying to find the best move by calculation. I.e. that you are trying to see 5 moves ahead to see if you can win more material. What I believe you should do is aim to look 2 and a half moves ahead and base those moves on your evaluation. This is particularly useful in non-tactical situations.

For example, in your first game you win material and have to solidify. At move 31, you make life more complicated for yourself with 31...b5. Why not offer to trade queens with 31...Qe4, which needs almost no calculation? That move follows the principles and is in line with your evaluation of having to solidify and trade down.

When ahead in material, your first priority should be to trade queens. This is a big reduction in material and reduces the opponents counter attacking chances a great deal
Don't spend so much time gaining more material. Spend time either solidifying your position or reducing the opponent's counter chances


What is the English maxim for "Rather losing a material / piece, than losing a tempo / an initiative"? Chess, Xiangqi (Chinese Chess) and Go all highly value the tempo/initiative.

The Chinese saying "宁失一子,不失一先" literally means

  It is better to lose material/piece, than a tempo/initiative.

(宁=prefer; 失=lose; 一=one; 子=piece (e.g. pawn, rook, knight); 不=not; 先=initiative, tempo, momentum)

I understand the principle/tactic, but I don't know how to express it idiomatically. Is there an English maxim for it?

If there hasn't been an established proverb in English, we may invent some.

For example,

@T.J.Crowder:

"Damn the material, full speed ahead!"

@Remellion:

"Speed over greed"

Pros: rhythm.

Cons: The saying emphasizes to accept your own pieces' loss; while "greed" is about taking your opponent's pieces.

I might not understand the Chinese idiom correctly, but to me it sounds like--

"Lose the battle but win the war"

--which has the meaning of, it is better to sacrifice some small thing for the bigger picture (to me, that sounds like the crux of the Chinese idiom you shared).


Understanding The Isolani Pawn After reading Chess structures of Mauricio Flores Rios, I have some initial questions on the Isolani (or isolated queen pawn).
The author shows this diagram:

Later, he proceeds to giving White and Black plans for the game. Here my questions arise.

White is supposed to start a kingside attack.
I can see no reason why one would do that. I mean White does not have a majority of pawns in the kingside. I would not clearly start doing anything on the queenside but I am not sure why I should do it in the kingside.

Furthermore, if the reason for why this kingside attack is justified does not lie in the pawn majority, I cannot see why the pawn distribution would allow White pieces to be arranged so as to threaten the kingside. White can place a knight on e5 but he can also put it on c5 so it is unclear to me.

I have this very same question also regarding the following pawn structure:

Later, the author suggests placing the Queen and a bishop forming an attack on the b1-h7 diagonal as well as a bishop on g5. These are reasons to start an attack to the kingside but again I am not sure why the pawn structure would suggest doing this.

My second question is why Black is supposed to benefit from the exchange of White light-coloured bishop. I can see this bishop supports the d4-d5 rupture but it seems somewhat exaggerated to exchange it simply for that (maybe there is a better reason?).

To answer your first question, in these structures, white has more space and because of that, he can put his pieces in more advanced positions. Black's king is usually on the kingside in these positions which makes the e5 square a great square for a knight. If the knight was on c5, then black could play b6 and kick the knight out. When the knight lands on e5, f6 would be unwise by black because it greatly weakens the e6 square. Basically, these pawn structures result in more space which means it is easier to maneuver and therefore, start an attack. Also, these pawns are a short term advantage, and without quick action, black could quickly arrange his pieces to attack your d4 (and c4) pawn(s).

Black would benefit with an exchange of light squared bishops because of the fact that the e6 pawn blocks the activity of black's light squared bishop. White's bishop is very strong on the b1-h7 diagonal, therefore, in a majority of circumstances, it is favorable for black to exchange light-squared bishops.


I'm new to chess-what should be done here to win the game? [FEN "8/8/8/8/3k1KB1/8/8/8 w - - 0 1"]

I am new to chess and have no clue as to how to win this game. Which moves can be done with what is on the board in order to win? Could anyone explain?

This position is a draw, the game is over. It is not possible for either side to checkmate the other from this position, not even if the side with the bare king would try to help.
The same is true for king and knight vs king. A single knight or bishop without any pawns or other pieces is not enough to win the game.
With king and two knights vs king it is in theory possible to checkmate the other side, but it can't be forced. It's very easy to prevent the checkmate as the defending side. So that is essentially a draw too.
Two bishops, or a bishop and a knight, can force checkmate. It's not easy (especially bishop and knight, it has happened that a grandmaster fails to do it), but it can be done.
It's a better idea to always keep a pawn or two on the board so you can promote one.


Learning chess theory I have played a lot of chess in my childhood. And I'm quite a decent player as well. However I stopped playing for few years now. Only after I realized that there are lot of opening/middle/closing text book moves like 'kings Indian defense' etc. if I start fresh once again, how should I start learning these text book moves and implement it? There was no one to coach me in childhood so I never knew all this.

When you state that you are quite a decent player, exactly what do you mean by that? Do you mean that you have been producing relatively good results in actual chess tournaments, or do you mean that you usually win when playing against casual players? If the first description fits you, then studying opening theory may bring some value. In this case, you should try to understand why the moves are played in the opening instead of just memorizing variations, as the latter won't prepare you if your opponent steps out of theory. Look at famous games played in the opening and reflect over the moves that are played.
(Edit: And as r4 pointed out in his answer: don't be afraid to play the opening a lot!)

In the other case it will probably be completely pointless to study specific opening theory, as there are other things you need to learn first to become stronger. In this case it's better to review the basic opening principles about development, center control, piece activity and king safety, and follow them. In the vast majority of cases they are sound enough to give you an advantage against weaker tournament players, if you master them.


What are the most characteristic signatures if an opponent cheats in online game by using an engine? Sometimes I feel that a human, particularly a human of about my elo rating, would not ever play so.
I never used an engine in my life for cheating, but I think it is not so hard.
I think, most of the cheaters does not automatize "well". Thus, he has no way to step with the engine on the spot, instead if he switches to it, he needs to duplicate the state. This gets some time - maybe a minute - for him. After that, he starts to play astonishingly well.
If I experience this pattern, I report it, but there is a bitter feeling. Obviously reporting someone beause I lost is no good. I think I should do this only if I am sure, but I can never be sure.
There are rumors that chess.com has some very sophisticated technology to detect engine cheaters, but I doubt that they could really do it. I believe that they do their maximum (like utilizing some AI to measure the "human-ness" of the steps of the players), but I think anything what they could do, can be easily gamed (like using the engine only for some, critical steps of the party).
Do maybe some other patterns exist, which could raise the doubt?

There are a range of factors sites use;
Such as play style, move depth , skill level vs move skill level. Engines are emotionless and are willing to just commit.
Things such as ;

Move depth not comparable to skill level
Move Time being consistent eg 5 seconds per move (hard to demonstrate her)
Consistent string of flawless games

Move depth not comparable to skill level
I have the following of a game played recently in an club vs club tournament on Lichess. This juniors game was detected as having cheating in it. Whilst it was being played people were suspicious by the two particular moves highlight below.
This highlighted moves are something you would expect to see of players rated 2000+ and isn't a natural move to find especially for juniors. The human brain sees the rook move and discards it almost immediately as a Rook trading for a Bishop. I have reviewed the games since and found that the move list was 1 for 1 the entire time for black against StockFish 10
[White "White "]
[Black "The Suspect"]
[Event "Hyper Aggressive Sacrifices (Blitz 3|2)"]
[FEN "2krr3/ppp2ppp/2n3b1/4n3/2P3P1/P3PN1P/1P1NB3/2KR1R2 b - - 0 18"]
[StartFlipped "0"]

1... Rd3! 2. Bxd3 Nxd3+ 3. Kc2 Nf2+ 4. Kc1 Nxd1 5. Kxd1

Another Example from the same game;
[White "White"]
[Black "The Suspect"]
[Result "0-1"]
[FEN "2kr4/ppp2ppp/6b1/8/2P1P1P1/P3rB1P/1PKN1n2/3R4 w - - 0 24"]

1. Rf1 Rxf3! 2. Nxf3 Bxe4+ 3. Kc3 Rd3+ 3. Kb4 Rxf3 3. Re1 Nd3+ 0-1


Sherlock Holmes vs Professor James Moriarty, A Game of Shadow-Chess Game Position Reconstruction The chess scene between Sherlock Holmes and Professor James Moriarty in the movie Sherlock Holmes: A Game of Shadows is one of my favorite movie scenes of all time. What intrigued me even more was discovering the fact that the moves for this chess scene are loosely derived from a position that occurred in an interesting tactical game between Bent Larsen and Tigran Petrosian (Second Piatigorsky Cup, 1966). The position is as below -

    [FEN "r2q1rk1/pp2ppb1/3pn1Q1/3R4/2P3B1/4BR2/PP4PP/6K1 w - - 0 0"]
    [White "Bent Larsen"]
    [Black "Petrosian"]

Here, Petrosian, playing Black did not capture the White queen, but instead played Nf4, which also lost the game. If he had played fxg6, then we have the sequence of moves that resembles the movie scene.

    [FEN "r2q1rk1/pp2ppb1/3pn1pQ/3R4/2P3B1/4BR2/PP4PP/6K1 w - - 0 25"]
    [White "Bent Larsen"]
    [Black "Petrosian"]

    1. Qxg6 fxg6 2. Bxe6+ Kh7 3. Rh3+ Bh6 4. Bxh6 Rf5 5. Rxf5 gxf5 6. Bf7 Qb6+
    7. Kh1 Qxb2 8. Bf8# 1-0

Starting with Bxe6, in descriptive notation spoken out, that is -

  "Bishop takes knight check"

  "King to rook two"

  "Rook to king's rook three check"

  "Bishop to rook three"

  "Bishop takes bishop"

  "Rook bishop four"

  "Rook takes rook"

  "Pawn takes rook"

  "Bishop to bishop seven"

  "Queen knight three check"

  "King to rook one"

  "Queen takes knight pawn"

  "Bishop to bishop eight, discovered check...and (incidentally) mate"

The only problem is, the moves

  "Queen knight three check"

  "King to rook one"

do not occur in the movie version, which brings me to my question-

Construct a chess position where the moves in the movie version make sense.

This means that there should not be any "obvious" move better than the ones Moriarty (whom we can consider to be a good chess player) played in that position. Thus, a position like the one below is ruled out, because Moriarty doesn't have to played "Rook bishop four" as he played in the movie, but can simply play "Rook bishop eight checkmate"-

  [FEN "r4rk1/pp2p1b1/1q1pn1p1/3R4/2P3B1/5R2/PP1B2PP/7K w - - 0 25"]

  1. Bxe6+ Kh7 2. Rh3+ Bh6 3. Bxh6 Rf1# (3...Rf5?? 4. Rxf5! +-)

Moreover, considering the fact that Moriarty sounded very confident with his move "King to Rook Two", the position must not "appear" to be objectively bad for Black. At the very least Black should "look" equal or even materially better. EDIT: April 21 2014 2:35 PM GMT The same applies to "Rook Bishop Four" Moriarty saw the obvious line after RxR, PxR and BxP check, but probably missed Bishop to Bishop seven.

Note: Although Sherlock Holmes played Black in the actual game, for the purpose of this question, we can assume he was White.

Here is my current solution. For convenience and resemblance to the Larsen-Petrosian game, I have assumed Sherlock Holmes is White.

    [FEN "1q3rk1/2p1p1b1/r1Ppn1p1/3R4/6B1/4BR2/PPn3PK/8 w - - 0 3"]

    3. Bxe6+ Kh7 (3... Rf7 4. Bxf7+ Kf8 5. Bxg6+ Bf6 6. Bh6+ Kg8 7. Rg3 Nd4 (7...
    e6 8. Rh5 Be5 9. Rxe5 dxe5 10. Be4+ Kh8 (10... Kf7 11. Rg7+ Kf8 (11... Kf6 12.
    g4 Qh8 13. g5#) 12. Bh7 Rxc6 13. Rg8+ Kf7 14. Rxb8) 11. Bg7+ Kg8 12. Bh6+) 8.
    Rh5 Ne2 9. Rg4 Be5+ 10. Rxe5 dxe5 11. Be4+ Kf7 12. Rg7+ Ke6 13. Rg6+ Kf7 14.
    Rg7+) 4. Rh3+ Bh6 5. Bxh6 Rf5 6. Rxf5 gxf5 7. Bf7! (7. Bxf5+? Kg8 8. Be6+ Kh7 9.
    Bf5+ (9. Bf7? Qc8 10. Rh4 Ra4! 11. g4 Qxg4 12. Rxg4 Rxg4)) 7... Qxb2 8.
    Bf8# (8. Bc1+ Kg7 9. Bxb2+ Kxf7)

Explanation:

After Sherlock plays 1. Bxe6, Moriarty is confident that the game is a draw by perpetual, so he plays 1...Kh7 immediately. Moriarty is unwilling to enter the complications of 1...Rf7, which also leads to a draw but gives a very complex position. After 1...Kh7, the forced sequence of moves arrives till 6...gxf5 when Moriarty expects Sherlock to take the pawn on f5 and give a perpetual. Instead, Sherlock plays 7. Bf7 and now Moriarty realizes it's over.

The variations show why 7. Bf7 leads to mate but 7. Bxf5+ leads only to a draw for Sherlock.


Is there a low-end ELO Deflation? I've heard often about Elo Inflation among the top chess players, meaning that a player rated 2650 Elo nowadays is weaker compared to a player rated 2650 Elo player 10 years ago.
I'm curious if there's an opposite phenomenon on the lower end of the Elo bell curve:

Is a 1500 Elo rated player nowadays stronger compared to a 1500 Elo rated player 10 years ago?

I have this 'feeling' based on my personal experience but no data to back it up.

Update: I'm referring to FIDE Elo ratings.

These questions of rating inflation/deflation over time are very tricky to answer objectively. It is very easy to find mid-range players who will say something like "My rating today is about 200 points lower than it was 10 years ago but I'm just as strong if not stronger [spot the wishful thinking] therefore there must have been rating deflation at my level during this period". Full disclosure: I'm one of those mid range players :-)

To get more objective views (I think definitive answers are another, more complicated, matter) you have to look at how many players were above a given level today and 10 years ago and perhaps also the percentage of players who were above a given level today and 10 years ago.

That data is available via the FIDE rating website where it is possible to download rating data going back to 2001.

Here are the figures from the January 2019 and January 2009 lists:

January 2019
Players rated above 2650 = 109 (0.0335%)
Players rated above 2100 = 40940 (12.6%)
Players rated above 1500 = 224873 (69.1%)
Total rated players = 325306

January 2009
Players rated above 2650 = 75 (0.0756%)
Players rated above 2100 = 40044 (40.35%)
Players rated above 1500 = 98669 (99.4%)
Total rated players = 99232

Interpreting these figures is difficult, particularly the percentage ones.

If you just look at absolute values then there are a lot more players graded over 2650 today than 10 years ago and the same for players rated over 1500. This suggests rating inflation at both levels. I've also included values for players over 2100 because, intriguingly, these are almost unchanged.

If you look at percentage values then a much smaller percentage of players are rated over 2650 today than 10 years ago and the same for players rated over 1500. This would suggest  a great deal of rating deflation at both 1500 and 2650 levels. The deflation is highest, however, at the 2100 level (out of the three levels I have looked at).

However, I think the percentage values are problematic. First if you look at the 1500 level 10 years ago there are only 563 players with ratings <= 1500. I suspect that this is because the only FIDE rated tournaments for players below 1500 were tournaments like continental and world junior tournaments going down to levels as low as 1001.

By the way, the first player I can find to have had a rating just above 1500 was the Polish player Sebastian Kobus. His first rating was 1500 in January 2006. For 1000 it was Indian player Hakeem Nikhil with a rating of 1003 in September 2012. The first sub 1300 player was French player Michel Khechab with a rating of 1260 in September 2009.

There were, of course, a lot of players playing tournament chess whose strength was below 1500 but they were all playing nationally graded chess because there simply were no FIDE rated tournaments for players that weak outside the big FIDE championship tournaments. Those figures show that today over 30% of players have a FIDE rating of 1500 or below compared to just 0.6% 10 years ago.

My tentative conclusion is that there has been some rating inflation at the level of 2650 and above because there has been a 45% increase in the number of players rated over 2650 which I think cannot be accounted for by increasing number of chess players.

I think there has been a lot of deflation in higher mid-ranges (typified by the 2100 figures) because there has been some increase in chess playing numbers which is not reflected in higher numbers at these levels.

At the lower mid-range (1500) I think the data is unreliable 10 years ago due to the very small number of tournaments open to players of these levels and so it isn't possible to draw any conclusions about this level.

Regarding the data for players at the 2100 and 2650 levels I think this is reliable because I think FIDE rated tournaments were capturing most players at these levels.


Is it a draw by insufficient material if the board is K vs K, N & N? It isn't possible to force checkmate with King vs. King, Knight & Knight. A checkmate position, however, is still possible to achieve, so does that mean the 50 move rule applies, or does insufficient material mean insufficient material to force checkmate?

This is a complicated situation, and it is made even more complicated by the fact that USCF and FIDE rules differ slightly.

First and most importantly, the 50 move rule always applies.  If 50 moves are made without a capture or a pawn move, then the game is simply declared drawn.

The rules about insufficient material only are important when one side runs out of time.  Basically, the rule says that if a player runs out of time, and the opponent does not have enough material to mate, then the game is declared drawn instead of the side with time remaining getting the win.  For example, if black has a lone king and white flags while trying to mate with a king and queen, the game is a draw.  If there is insufficient material to deliver mate, an OTB game can also be declared drawn even with time on the clock if a tournament director is summoned.  This will only apply for cases like K vs K or KN vs K.  Usually it is not an issue because the opponent will simply agree to a draw.

So now to the specific case of KNN vs K:

FIDE

Under FIDE rules for standard tournament time controls, if the side with just a king runs out of time, then the side with KNN wins because a mating position can be constructed.  If the side with just the king avoids one move mates, however, then mate cannot be forced.

USCF

Under USCF rules, if the side with just a king runs out of time, then the game is declared drawn.  The USCF focuses on the fact that checkmate cannot be forced.

Online Play

Many online chess servers will automatically stop a game when there is not enough material left on the board to mate.  In the specific case of KNN vs K most servers do not automatically give a draw (following the FIDE rules).  One interesting case is KN vs KB when Playchess and ICC will stop the game and award a draw (not following FIDE rules) while Chesscube follows the FIDE rules and continues play.

Practical Play

Now for practical play, if you are defending with just the king, it is very easy to avoid mate for 50 moves, even if you have almost no time remaining.  Make sure that you don't move to a square where mate can be delivered next move and you will never be forced into mate.


What should a player do in blitz if he knocks a piece on to the floor after pressing the clock? This question is prompted by an incident in today's World Blitz championship in Moscow as described and shown in this tweet.

What happened was that Nakamura made a move, pressed the clock, on the way back from pressing the clock his hand caught his rook and knocked it off the board about 10 cm. He immediately picked up the rook and replaced it. This maybe took half a second.

His opponent, Sergei Zhigalko, thought for about 12 seconds before having a long look around, presumably to see if an arbiter was watching the game. Then after another 2 or 3 seconds he gestures over to the arbiter to call him to the board and indicates something with his hand. Finally 22 seconds after the incident he reaches out to pause the clocks. There then follows a long discussion between the players and the arbiters which suggests that Zhigalko was trying to claim an illegal move before the game continues with no action taken.

Nakamura acted perfectly correctly here IMHO, but what should he have done differently if instead of displacing the piece a few inches he had knocked it onto the floor requiring several seconds to retrieve and replace the piece?

The relevant section from the rules would be Article 7.4.1:

  If a player displaces one or more pieces, he shall re-establish the
  correct position in his own time.

The rules do not specify a certain procedure, but what I have seen happening in practice is: Player A knocks a piece over on his opponent's time. Player B is now allowed to press the clock to make sure he does not lose time. After the correct position has been reestablished, player A will press the clock again so player B has the move. I certainly don't feel the rules mandate that the arbiter needs to be summoned in this case.

If the displacement caused an unusual disturbance or the affected player is very low on time (<10sec), as an arbiter I would consider applying Article 12.5 regarding external disturbances and add something in the range of 20-30 seconds to the clock of the affected player.

The following objections could be raised, although I feel they are rather academic in nature:

It would be in the spirit of the rules if the person displacing the pieces would stop their opponent's clock and start his own again. However, I have never seen this happening and it may well be inadvisable to do that just for practical reasons, depending on the circumstances.
If the game is played with increment, the additional two clock presses add time to the players' clocks. Therefore, the clock settings (times and move counter) would be incorrect after such an incident. However, at least in the German-speaking chess community, Article 6.10.2 is generally considered to only apply in cases where there is a non-negligible time difference. As a rule of thumb, it should take an arbiter at most one minute to adjust clock settings. If the time differential to be corrected is smaller, the arbiter should not interfere. Additionally, the move counter of the clock is not a reliable indicator of the number of moves played.

In the comments, Article 7.5.3 has been mentioned:

  If the player presses the clock without making a move, it shall be considered and penalized as if an illegal move.

This article has been added fairly recently to make sure a player can be penalized for pressing the clock for no reason. It should not be applied if the player enforces the rules.

Making a move and then expecting to correct the position of a displaced piece defeats the purpose of the rule: The distraction by the missing piece is immediately affecting the other player.


How to learn an opening I'm a ~2100 Elo rated player at the moment, and lately I've been wondering about the best general way of learning openings, and eventually mastering them in some sense. Note that this question is not in the same spirit as the question What's a good way to learn opening theory?, already answered earlier.
My question is a general question about methods, in a few parts:

What are some good methods to pick up an opening you've never played before? Are there any differences in approach if the opening is somewhat familiar, or completely new (think going from the French to the e6 Sicilian as Black vs. going from the French to the Pirc as Black)?

If you've played an opening for a while, and you're not getting good results with the opening, how can you determine if the poor results depend on you not knowing enough theory/ideas or if it's more fundamental, like the opening not suiting your style?

How do you determine if an opening book/DVD/[Whatever thing that costs money] will help your understanding of an opening before buying it? It's not very fun to buy something that won't be very useful in the long run.

Is it even necessary to get books on openings to learn them? How much more difficult is it really to learn openings without books, and what are necessary things to consider if you're trying to learn an opening by studying games in a big database? How much does this depend on player level?

How much time is it reasonable to assume that it takes to master an opening on average? How much does this depend on the type of opening? Take, for example, the London system as White vs. the King's Indian Defence as Black, where the first is a "system opening" that's not very sharp, and the latter is incredibly sharp and complicated.

I don't think that this is the type of question that can have only one good answer, and I would hope to see different people mentioning their methods of choice for learning openings. It's not easy to learn to play an opening well, if you don't know what's necessary to learn. I mean, otherwise every grandmaster would be as good on the Black side of the Najdorf Sicilian as MVL.

Try to understand the key idea behind the opening, and try to relate each of the main moves to it. If you can't do this, you don't understand the opening.
First test the new opening by playing it against players weaker than you (in your case, <2000). If you are getting bad results, it means that the opening doesn't suit your style. Then test the new opening against players stronger than you (>2200). If you are winning more games that usual, the opening is "value added;" otherwise it's "back to the drawing board.
If I buy a book or DVD, it's because something I've seen makes a "lightbulb" go off in my head. If I don't have this "aha" moment, I don't buy the item.
The greater your strength, the less benefit you will receive from books, and the more benefit from your own study. If you are the "smartest kid in class," you won't benefit much from reading others' papers.
Depending on the opening, mastery could take from a few months to years. Some GMs spend a lifetime trying to understand one opening.


Is there a Web Service available for 6-piece endgame tablebases? I use the LokaSoft web service for 5-piece endgames, but cannot find one for 6 pieces.

BTW, by web service I mean a software function capable of being called over the internet (see http://en.wikipedia.org/wiki/Web_service), not simply a service being offered on the web.

We can find several website giving 6-piece endgame tablebase, the tricky part is probably the way you want the information back.
Here is 2 examples of endgame tablebase :

http://www.shredderchess.com/online-chess/online-databases/endgame-database.html
http://chessok.com/?page_id=361

In both of this example you can ask a position by putting FEN code, so there is probably a way to use it as a webservice. (Perhaps you'll have to use a script)

Also another suggestion, on the link section of http://en.wikipedia.org/wiki/Endgame_tablebase you can find Nalimove database and try to make it communicate with your software.


What does autopilot mean in chess? I've seen people saying things like "from now on this is just autopilot" or "autopilot from move 20"

I think overtheboard is mostly right, especially because your quotes seem to have this gist, but there is another aspect to playing on autopilot in chess, more often referred to as "playing by hand", i.e. without using you head.

If you reach a certain level in chess, in almost all positions a "typical" move represents itself to you, not necessarily the best move, but with high probability a decent move. This phenomenon is closely connected to the term priyome, which refers to standard positional responses and methods, that somebody with a certain amount of chess culture just knows.

So if somebody talks about playing on autopilot or playing by hand, he might just mean choosing natural strong moves without looking deeply into the position. Often this is enough to beat weaker players and it can be done in all kinds of positions, not just in easily winning ones or in forcing lines.


Why is castling here a mistake? I am back at chess after two years and am enjoying it a lot. I was playing and this happened after I checked a report at chess.com:

I have googled the importance of when to castle the king. Here I know castling isn't the best move, but why is it a mistake?

The engine is giving you an answer. Black plays ... Na5 followed by ... Nc4 which prevents White from bringing pieces over to the queenside, because of the White doubled pawns on c2 and c3. Which means the White king is now stranded by itself on the queenside.
Black is going to play ... c5 and bring the queen out to a5 or b6. On a5 it threatens ... Qxa3 with mate to follow. On b6 it's threatening ... Qb2 with mate.
What queenside castling has done is to put the White king into the line of fire, in a way that Black has at least two pieces converging to attack, and White has none. Even, if by miracle, White gets some pieces over to the a- and b-files, Black's other pieces will enter the fray much quicker and in much larger numbers: The a8 rook by pushing the a-pawn, the c8-bishop via d7.
The chess engine reckons White is going to lose at least a rook to stave off this attack (this is simply the difference between the position evaluation after queenside castling -6.27 versus the best move Nf3 which is evaluated to -1.74).
In logical terms, you castled into an attack on the queenside. With the centre as constricted as it is, your king was fairly safe remaining in the centre uncastled for the time being. You needed to develop the Knight to f3, and the bishop to e2, and take it from there.


The best move in this Crazyhouse position according to Stockfish I just played my first few games of Crazyhouse, and I really don't understand it. At one point I had this position.
[Title "White to move"]
[FEN "r2q1rk1/pbb2pp1/n1p1p2p/1p1nP3/2pPN3/P1P3P1/2BN1P1P/R1BQ1RK1 w - - 1 16"]

Black has no extra pieces, while I (White) have an extra pawn.
Stockfish 10+ on Lichess (depth 18), says I have an immense advantage of +11.2, it and recommends Nxc4, but I have no idea what general strategy is behind this move. I had instead chosen Qh5, which it does not even place in the top 3 moves but thinks is fine too after I make the move, and I know what I am doing with this move.
Upon playing out a few lines extending from Nxc4, I get the feeling that the chess engine may have been mistaken about its value. Is it unreliable for Crazyhouse, or is there some underlying strategy behind that move that I am not seeing?

I can not exactly reproduce it on the lichess analysis board, but the move Nxc4 still seems to be among the top 3-4 moves with a similar evaluation as the top moves. The main idea in this position should be to undermine the dark squares f6, g7, h6 on the king side. Nxc4 aligns well with this idea, since it opens up the bishop's attack to h6 and gives an additional pawn in hand, so after a subsequent P@f6 white still has another pawn for the attack.
The Stockfish fork used on lichess is far above human level in crazyhouse, so usually its analysis should be quite reliable, although it of course also is not infallible and might miss moves/ideas or misevaluate resulting positions.


Why is 1. Nf3 not nearly as popular as 1.e4 and 1.d4? The opening move 1. Nf3 is considered as a perfectly sound opening and it is popular, but not nearly as popular as 1.e4 and 1.d4. Here are my thoughts about this:

In most openings, white will make the move Nf3 sooner or later. Since white needs this move (in most cases) anyway, why not make it the first move?
White has much flexibility with 1. Nf3. Here are a few examples:

For 1. Nf3 Nf6, white may reply with either 2.c4, transferring to the English or 2.d4, transferring to Queen's Pawn Game.

For 1. Nf3 d5, white may continue with 2.d4, transferring to Queen's Pawn Game.

For 1. Nf3 c5, white may reply with either 2.c4, transferring to the English or 2.e4, transferring to Sicilian.

At the same time, white is not afraid of some weird replies such as 1. Nf3 e5 as replying this with 2. e4 is perfectly fine for white. Capturing the pawn may be fine for white as well.

Why then is 1.Nf3 not nearly as popular as 1.e4 and 1.d4?

It is funny since 1.Nf3 scores better than any other opening move per Mega 2020 at 55.5% winning percentage for white, compared to only 52.8% for 1.e4, 54.3% for 1.d4, and 54.4% for 1.c4.

I think a lot of it is psychological regarding the types of positions that can arise. 1.Nf3 is the most fluid of all the moves I mentioned, and I think that players simply like more concrete play than not. It also reduces what you need to memorize, or understand, if you go straight into a specific pawn formation with d4, e4, or c4.

I also think that at the lower levels, that fluidity can lead to positions that players, both players, but since it is white's choice, that he/she specifically is not as comfortable with since he/she can end up on his/her own in a hurry. You need to know A LOT more about transpositions into other openings, which is a major undertaking. The play is also more complicated, which drives weaker players away more.

At the upper levels, meaning 2700s, I do not believe that they are afraid of getting lost in the opening as easily, but there still may be an underlying desire to play
"their" openings, so they play more concretely.

One thing I do not believe is that after 1.Nf3 that 1...e5 is a valid response. White, having played 1.Nf3 probably likes d4/c4 openings, so is not likely to go into a double-king-pawn opening, but still has a great response:

 [FEN ""]

 1. Nf3 e5? 2. Nxe5!

Thanks for the gumball, Mickey! (from an old U.S. commercial for a Mickey Mouse gumball machine)

Based on my discussion with Phonon below, I am adding this chart that shows the flexibility of each main opening move that aims for the closed openings (d4/c4/Nf3). At the higher levels, this is a main reason, but at lower levels, I still believe that it is more about psychology, and believing that immediate occupation of the center is crucial. At lower levels this also can often put your opponent on unfamiliar grounds,


What is the highest number of different mates in 1 you can have in one (legal) position? A friend and I yesterday asked ourselves what the highest number of possible mates in a (legal) position is. We were able to come up with the following position which has a total of 76 unique mates in 1, but we then failed to improve upon this one.

Q3Q3/4K2Q/6R1/3R4/QB2k3/5R1N/2R5/QQ1Q1N1B w - - 0 1

Do you know if this problem ever has been solved and what the highest possible number is? It was hard for us to come up with a reasonably low upper bound so that I have no idea whether this solution is close to the maximum.

[FEN "1B1Q1Q2/2R5/pQ4QN/RB2k3/1Q5Q/N4Q2/K2Q4/6Q1 w - - 0 1 "]

105 mates — Nenad Petrovic, Sahovski Vjesnika 1947 (Chess Problem Database)

In this position any check is mate. There are 3 knight mates (c4, g4, f7), 23 discovered mates (14 moves for the rook on c7, 9 for the bishop on b5), and 79 queen mates: 1 on a1, 2 on b2, 3 on c3, 4 on c5, 6 on d4, 3 on d5, 6 on d6, 3 on e1, 2 on e2, 4 on e3, 4 on e4, 2 on e6, 4 on e7, 3 on e8, 5 on f4, 3  on f5, 6 on f6, 4 on g3, 5 on g5, 2 on g7, 3 on h2, 3 on h5, and 1 on h8, for a total of 105 mates.


Explaining knight move to kids I am currently teaching a kid (~6 years) chess and we started with the pieces.  While she had no trouble picking up the rules for the rook, the bishop, the queen and the king, the knight seems more difficult.

I explained that the knight takes two steps horizontal or vertical and then it makes a turn and one more step.  While with the other pieces she immediately "sees" which moves are possible, for the knight she is now counting, counting and counting.  I think she already got better and sometimes just "sees" where she can move, but often she does not.

Now I have the following questions:
Will this problem just vanish with increasing practice?  Or is the way I introduced the knight move not suitable?

Should I try and explain the knight move differently, e.g., more visually? In this case I would be thankful for any suggestions.  So far I have refrained from giving alternative explanation to avoid confusion.

This problem does vanish with time, but it takes longer depending on the person... Personally when I teach others about the knight movement I explain it with the "L" letter.

If they draw the letter L horizontally and vertically they will get all the squares he can go to. This is in my opinion simpler to understand as they will be using a letter they already know, it's not something they will need to learn in order to use it.

This would obviously not work if she does not know English letters, but hopefully this gives you an idea on how to make it easier.


Do you get an extra turn when you promote your pawn? If you promote a pawn do you get a second move to move it out of danger? Or do you still only get the promotion as your move and it becomes the opponents move?

Once you have promoted your pawn do you get a second move to move it out
  of danger?

No.

  Or do you still only get the promotion as your move and it becomes
  the opponents move?

Yes.

From the FIDE Laws of Chess:

  3.7.e When a player, having the move, plays a pawn to the rank furthest from
  its starting position, he must exchange that pawn as part of the same
  move for a new queen, rook, bishop or knight of the same colour on the
  intended square of arrival.

There is no discussion of extra turns.


What is the current theoretical state for the Chinese Dragon? I use this line a lot, as it tends to lead to interesting games, and I was wondering whether any advances in theory have been made here.

[FEN ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 O-O 8. Qd2 Nc6 9. Bc4 Bd7 10. O-O-O Rb8

Wikipedia

When black plays the Dragon, recently, the top players tend to choose 9.0-0-0 and 9.g4, instead of 9.Bc4. For example, Topalov-Lu Shanglei, Wei Yi-Lu Shanglei, Caruana-Nakamura and Karjakin-Nakamura.

According to the Game Database of ChessTempo, after 9.Bc4 Bd7 10.0-0-0, 10....Rc8 is the most popular choice. A couple of months ago, two books about the Dragon have been published, written by GM Jones. In Volume 1 he recommends 10....Rc8 and a couple of days ago, he used this move to beat GM Yu Yangyi.

However, according to the Game Database of ChessTempo, 10....Rb8 scores close to 50% with a performance of 2410, for players with an average rating of 2407. This indicates that 10....Rb8 is a good alternative for 10....Rc8.

White usually continues with 11.Bb3. After 11....Na5 12.Bh6 Bxh6 13.Qxh6 b5 14.g4, white does seem to be slightly better. Recent games of strong players are: Mamedov-Can, Ledger-Jones, Saric-Cvitan, Demchenko-Kanter and Georgiadis-Cvitan.
The same position can arise after 12.g4 b5 13.Bh6 Bxh6 14.Qxh6.

      [FEN ""]
      [StartPly "20"]

      1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3 O-O 8.Qd2 Nc6 9.Bc4 (9.O-O-O)(9.g4) Bd7 10.O-O-O Rb8 (10...Rc8) 11.Bb3 Na5 12.Bh6 (12.g4 b5 13.Bh6 Bxh6 14.Qxh6) Bxh6 13.Qxh6 b5 14.g4


What are good resources for how to play against the french as white? I have been looking all over the web for a good way to counter the french defense, but nothing really helps. If you have any suggestions please tell me.

The main problem you have playing against the French as white, particularly if you don't play it as black, is that there is just so much theory to learn. If you try and play either  the Tarrasch or the Winawer you don't know if you are going to get a wild tactical game or end up in a tame, boring Rubinstein. Your opponent makes the choice. Even if your opponent declines to play 3 ... de there are still many ways for black to play and they are ways where one small error can lead to an instant lost game.

Your best bet then is to either play the Advance variation with 3. e5 or the more boring Exchange variation with 3. ed. The Advance gives more scope for tactical play and the Exchange more scope for positional play, although you can still have sharp games in the Exchange. They just tend to have a longer fuse. Either one will leave you much less to learn than either the Tarrasch or Winawer with much less chance of a quick loss.

Whichever one you choose learn it thoroughly and stick with it.


The difference between Rad1 and Rfd1 I've always wondered, what are the main tactical and strategic differences between Rad1 and Rfd1 (or Rad8 and Rfd8 as black)? I know it's a subtlety, but my guess is there are some common principles that apply often.

When you move one rook to the center, the other rook, obviously, cannot cross it. If you play Rfd1, you cannot then play Rae1. And if you play Rad1, you cannot then play Rfc1. So, part of this decision is planning ahead and thinking about which other file you are likely to want a rook on.

Relatedly, if you play a move like Rae1, you are trapping your f-rook, often making it vulnerable to an attack from the bishop. Be careful before playing a move like that.

If the opponent has a bishop on g7, it is sometimes a good idea to get the rook off of the a1 square, especially if the center is not closed. This allows you to more easily play b3 or b4 without putting your rook in danger from the bishop.


In the United States, what are the universities and colleges with the best chess club? Webster University undeniably takes first place.

But I would like to know more American universities and colleges which have a big chess club.

The top four US college chess schools participate in the Final Four of College Chess. This year's (2015) participants were Webster University, the University of Texas at Dallas, Texas Tech University, and the University of Maryland, Baltimore County. Especially, the University of Texas at Dallas and the University of Maryland, Baltimore County, have consistently had very good results in the Pan American Intercollegiate Team Chess Championship in the last ten to fifteen years.

You can find other college chess clubs at the site of the USCF.


Why is ...e5 dubious here? [fen ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5?!

Why is ...e5 considered dubious for Black here, although it is considered sort of a refutation after the move 5.f3?! e5!

What's the big difference? If it is strong after 5.f3, it shouldn't be so bad after 5.Nc3, the pawn structure is the same.

The problem with e5 is that after 6.Bb5+ white will be able to play the manoeuvre Nf5-Ne3 which will result in an iron control of the d5-square. (Without Bb5 the knight on f5 could be taken by the Bc8).

The difference to the 5.f3 line is, that f3 doesn't control d5, so when the knight lands on f5 the counterstrike d5 will be possible.

[fen ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5?! 6. Bb5 Bd7 7.Bxd7 Qxd7 8. Nf5


Thoughts on this game, please I played the below recently in a U145 ECF (~U1800 FIDE) rapidplay, and would appreciate your thoughts. There are obviously lots of tactical errors, and please be kind on the last few moves which were played in a desperate time scramble by both sides, made worse by prize money almost certainly hanging on the game, but any constructive comments would be appreciated. The 1-0 result is because black tried Nxa3+ at the end missing the check from the white queen, and so losing on the illegal move rule,

Ian

[Event "?"]
[Site "?"]
[Date "2015.09.12"]
[Round "?"]
[White "Somebody"]
[Black "Somebody Else"]
[Result "1-0"]
[ECO "B08"]
[PlyCount "79"]
[FEN ""]

1. d4 Nf6 2. Nf3 g6 3. Nc3 d6 4. e4 Bg7 5. Be3 O-O 6. Qd2 Ng4 7. Bg5 h6 8. Bh4
c5 9. h3 Nf6 10. O-O-O cxd4 11. Nxd4 g5 12. Bg3 Nh5 13. Bh2 a6 14. Be2 Nf6 15.
h4 g4 16. Bf4 e5 17. Bxh6 exd4 18. Qg5 Nh5 19. Qxh5 dxc3 20. e5 Qb6 21. b3 dxe5
22. Bxg7 Kxg7 23. Qg5+ Qg6 24. Qxe5+ Qf6 25. Qg3 Nc6 26. Rd5 Rg8 27. Bxg4 Kf8
28. Rg5 Rxg5 29. hxg5 Qxg5+ 30. Kb1 Qg7 31. f3 Bxg4 32. fxg4 Rd8 33. a3 Rd2 34.
Qc7 Qg6 35. Qc8+ Kg7 36. Rc1 Qe4 37. Qxb7 Qxg2 38. Qxa6 Nd4 39. Qc4 Nxc2 40.
Qxc3+ {Black now played Nxa3+ and lost on the illegal move rule} 1-0

All that I have analysed from the above game are enlisted below. I don't know which side @Ian Bush was on, so I am making suggestions for both sides. Hope it helps. Here it goes:

FOR WHITE

White had a slight positional disadvantage in the game as early as move no.7 since by this time, Black had castled, king is in safety, king-side pieces well developed, but White had a centred exposed king, queen-side pieces developed before king-side pieces (against golden rule), center pawns e4,d4 not supported by any pawn.
White should have played 3. c4 which is more mainstream and allows White an early control of the centre which can add to his advantage in the middlegame.

o-o-o is not a good move because of the fianchetto bishop on g7 and also the centre is very dynamic. So white loses the opportunity to attack on the kingside early as Black has the option to blow up the center and rupture the attack.

Bf4 is dubious. Better is 16. Nf5 which attacks the g7 bishop and occupies much space on the king-side and if it is captured by the bishop, pawn recaptures and the kingside attack is easier for White now.

Bg4 is better and is followed with the idea of Rd5..h5..h6 which tries to mend the position.

f3 might have been replaced by 31. Qd6 followed by 31. .. Kg8 32. Bf3 going for a fightback.

Qh8# could have sealed the game however.

FOR BLACK

.. Ng4 seems premature. Developing Queenside pieces might have been better.

.. Qf6 would have been better, aiming for 31. .. Bg4 and 32. .. Rd8.

.. Kg7 is a blunder. 35. .. Rd8 is quite stable.

.. Nd4 was the best move.

Otherwise Black had a good game and the final position was almost equal , a little in favour of Black. However the game could go anyway because of White's passed pawns.


Good apps for engine vs engine matches I'd like to hold engine vs engine matches on my phone, and am looking for an app which could help me do this. Does Droidfish support matches between two different engines?

If not, could someone name an app available on Play Store (with a good UI) which, in addition to allowing the usual functions of game analysis and playing against engines, supports engine vs engine matches, the two engines being different?

In short, I want something like Droidfish, with an additional feature to hold engine vs engine matches, like one can on Arena.

https://play.google.com/store/apps/details?id=com.google.android.chess&hl=en

Chess for Android has it, and it's the more or less industry standard for running engine matches on an Android mobile device.

I'm not sure if Droidfish can do it, somebody else might answer you.


Do chess AIs still use old-style opening books? (See also this related question and this related off-site discussion.)

Do state-of-the-art chess AIs still normally start games in human-compiled opening books of master games?

Years ago, as far as I know, state-of-the-art chess AIs started games in opening books. That is, years ago, to choose their first few moves, rather than calculating, chess AIs instead consulted databases of master games.

Do chess AIs still do that?

If you wish to know why I ask, more than 20 years ago, I owned a dedicated chess computer like one of these. The computer would instantly play each of its first several moves, apparently without thinking. The computer would slow down and start thinking only after

it had exhausted the book or
its human opponent had made a poor move, deviating from the book.

Nowadays, however, playing on Lichess, where the Stockfish AI is available for post mortem, I notice no obvious sign that Stockfish were consulting anything other than its own analyses.

(One suspects that various interesting things could be written on the topic. My knowledge of chess AIs is limited. I may or may not have posed the question optimally. Therefore, feel free to interpret the question broadly at your discretion.)

Chess engines are, of course, able to analyse opening positions and come up with reasonable moves, but opening books still come with some advantages:

Moving instantly in the opening saves a lot of time, which can be spent on more complex moves later on in the game.
Some more subtle theoretical moves in the opening may be missed without an opening book.

In engine vs engine testing, the overwhelming majority of games are conducted starting from an opening position, but the engines themselves are not allowed their own books.

When playing a human, many chess applications use books, but delay their move anyway to give the impression that the program is thinking. This has the advantage of allowing said application to offer a greater variety of openings, whereas relying on the engine's analysis would lead to repetitive games.

In analysis, it is common for to only start from the first move made out of book, because it is likely that moves made in-book are reasonable.

Lichess is somewhat unique in that it uses the engine to analyse every move rather than using a book for the first moves. The analyses of many opening positions are stored in the cloud to avoid duplicating work in the opening (you may see, for example, "Depth 39 [CLOUD]").


Why develop knights before bishops? So, I've found the general advice that you should develop your knights before your bishops.
Reasons I think are:
1) The knights almost always go to the main squares (c3,c6,f3,f6) (or sometimes to d7 the black knight in the queen's gambit) but, generally, you know in advance that you are likely to want your knights there. However, the bishops you don't want to commit to a square and "reveal" your intentions.

Of course this rule has a lot of exceptions, starting with the ruy lopez Bb5, italian game Bc4 are better for white than 3 Nc3.

But I've seen this rule for example here1. In that quora question, 5 answers reference my intuition that i describe below. Here also argues that while not universal, it is recommended normally. Other authority sources were founded using this article , in that , it can be found that Emmanuel Lasker and Reuben both recommend it:

  Bring out your knights before developing the bishops.

Intuition: is not to commit /reveal information by moving the bishop, and since the knight has almost only 1 great square in most openings (c3,f3,c6,f6) then there is nothing to hide and sooner or later it will be needed there, so just move right now. Keeps the bishop options open.

Commitment (versus flexibility) indeed is the main reason for this piece of advice. In particular:

The first moves are (usually) all about fighting for control over the center. The knights are superior to the bishops in that regard because from their "natural" development squares, they have access to 2 of the central squares (e.g. a knight on f3 reaches both d4 and e5 - attacking and defending the center at the same time), while the bishops can control at most one (e.g. Be3 reaches d4 and Bf4 reaches e5, so the bishop can only attack or defend the center, but not both) unless they are fianchetto'ed, but that has the cost of two moves to develop instead of one.
Half of the options to develop the bishops in one move (Bf4, Bg5, Bc4, Bb5) makes them vulnerable to the opponent's pawns (Be2, Bd2, Be3 and Bd3 are safe) which might cause you to lose tempo, while the developed knights are usually safe from pawn attacks after their first move.
a bishop may attack a developed knight on the bishop's first move (e.g. 2...Nc6 3. Bb5), a knight cannot attack a developed bishop on the knight's first move. This slightly increases the value of developing the bishops only after a few moves.
never forget that this is just a broad rule of thumb, and there actually is a perpendicular one: To develop the pieces of one wing (typically kingside) before those of the other to enable you to castle as soon as possible. You will very often see the bishop on f1 to be developed before the knight on b1 (e.g. in the Ruy Lopez or Giuoco Piano), contradicting the rule to develop knights before bishops. From the fact that these two openings are by far more popular than the Four Knights, you can tell that these moves are very strong regardless!


Evans Gambit b4 loss I have already read the section here on the Evans Gambit but I still don't understand the value of sacrificing the b pawn unnecessarily, in the likely case that black's Bishop returns to the c5. White could have simply proceeded with c3, d4, gaining center control and attacking B. Why interpose losing a pawn? If it is to open the c1-a3 axis for B, then b3 should be played. Can someone explain why giving away the pawn, while black can simply take it and resume where it was, is a good move? Unless there is a need at that time that can be filled by giving away a pawn, I fail to see the value of this move.

Compare the position after 3...Bc5 to that after 4.b4 Bxb4 5.c3 Bc5 6.d4.

[fen ""]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Bc5 6.d4`

It's true that the Black bishop has simply returned to c5 and can retreat safely again, but note that that is all Black has gotten to do while White got in the central c3/d4 push. In simplest terms, the point of the Evans Gambit is that gain of time, getting in those moves to expand in the center (and open lines for potential development/attack) without Black continuing her development in the meantime. Such things usually aren't free of course, and here it has cost White the b-pawn. White has traded in a bit of material in attempt to have greater dynamic potential and the initiative.


Touch move rule loophole When I touch two pieces simultaneously, how will the touch move rule apply? How is this rule used for this situation? I could not find any resources to do with this situation.

When I touch two pieces simultaneously, how will the touch move rule
apply?

It will primarily depend on your intention, or rather what onlookers clearly perceive as being your intention.
Here's what the latest FIDE Laws of Chess have to say:

4.1 Each move must be played with one hand only.
4.2.1 Only the player having the move may adjust one or more pieces on their squares, provided that he first expresses his intention (for
example by saying “j’adoube” or “I adjust”).
4.2.2 Any other physical contact with a piece, except for clearly accidental contact, shall be considered to be intent.
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:
4.3.1 one or more of his own pieces, he must move the first piece touched that can be moved
4.3.2 one or more of his opponent’s pieces, he must capture the first piece touched that can be captured
etc.

The firs thing to note is that of you used two hands then that will be punished as an illegal move (article 7.5.4).
If it is clearly accidental then you will be permitted (required) to move the piece that it was clearly your intention to move. An example of this is something which sometimes happens to me when I reach across the board to move a piece on the far side and my forearm brushes and sometimes knocks over the tallest piece on my side of the board, my king.
So, that leaves cases where you deliberately touched two pieces simultaneously with one hand. There are two articles which deal with that in the laws, one more draconian than the other and so far less likely to be invoked.

11.5 It is forbidden to distract or annoy the opponent in any manner whatsoever.

If an arbiter saw you do this (deliberately touch two pieces simultaneously with one hand) then they would likely immediately warn you. If the opponent claimed that it was an annoyance you might receive more than a warning.
Repeat infringements would put you at risk of:

11.7 Persistent refusal by a player to comply with the Laws of Chess shall be penalised by loss of the game. The arbiter shall decide the
score of the opponent.

In extreme circumstances (I cannot think of any time this has been invoked) the arbiter could punish you under:

11.1 The players shall take no action that will bring the game of chess into disrepute.


Is this continuation of D85, Gruenfeld Defence, Exchange Variation, tenable? I am watching some commentary on the World Championship Games. This is from Game 1:

[FEN "rnbq1rk1/ppp1ppbp/6p1/8/3PP3/2B5/PP1Q1PPP/R3KBNR b KQ - 0 8"]
[White "Anand"]
[Black "Carlsen"]

The commentator states that Carlsen has several moves available to him at this point, including one which confuses me: 1. ...Bg4. I see that it stops White from castling, but after 2. f3 that Bishop seems silly. The pawn structure looks unfavorable but not fatally so after a bishop retreat. Alternatively, White can also play 2. Nf3, 2. Ne2 or 2. Be2 to set up an exchange.

What's the deal with 1. ...Bg4?

I have little idea about the Gruenfeld (hopefully someone who is more familiar or a better player than I am can give a more complete answer), but a few points you may have overlooked:

After 1...Bg4 2.f3, as you say the pawn structure is marginally weaker, but there's also a bigger problem of how white will develop the g1-knight. Nf3 is now impossible, Nh3 looks bad and if black's bishop stays on the c8-h3 diagonal he can then give white doubled h-pawns. Ne2 might look plausible,  but there's then a problem of how to move the knight from there. c3 and d4 can't be reached without a move vacating that square first, which will probably require other preparations as well, Nf4 too soon is dangerous as it could force white to make even more concessions in pawn structure if Bh6 is allowed, pinning the knight to the queen. Finally, g3 is a poor spot for the knight as the g6-pawn takes away two future squares and e4 is already being taken up by a pawn.
In grandmaster praxis, a draw with black is a respectable result, and trading off the bishops after 1...Bg4 2.Be2 gets black somewhat closer to this result.
1...Bg4 2.Nf3 gives white doubled pawns after the exchange, and the half-open file that results isn't that useful as it faces onto a reinforced pawn. It also leaves the knight on e2 (assuming white does not want to lose castling rights or lose the d4 pawn) with the same problems as mentioned above.


How are chess variations meant to be read This is a sample position from a book (no further details are given to avoid copyright issues).

I can read the first line and follow it in my mind, departing from the figure. But the continuation in the 2nd and 3rd line is too much. I cannot look at the figure and remember what pieces are supposed to be in different squares, much less do it in a proficient way (i.e. I might place a non-existing bishop in a square in my mind, but not realizing which other squares he is threatening).

However the book is not for advanced players. I wonder how are readers supposed to follow these comments and variations, if you are supposed to use a physical board with pieces, or if you are supposed to visualize all that in your mind and the problem is that I need more practice on that.

Visualization usually improves as you get stronger, and there are exercises that can be done to improve it.

When following lines in a book, most players use a board,  and sometimes two. The second one is used to explore those side variations,  without having to constantly reset the board and play from the first move. This can be done with either physical boards, or software, which makes it easier to follow a variation,  then go back to then main line with just a mouse click.


Best strategy for analyzing chess games played by a kid I am looking for ideas on how to have my 9 year old son analyze his chess games. Is there a software that he could use?  He may not want to analyze the already played games on a chess board by himself.

Beyond the fact that it's easier to go backwards and forwards through a game and try out variations on a computer than on a physical board (it remembers where the pieces were), software probably isn't very relevant because it's usually rather hard to interpret what the software is saying. Often it will highlight tactical blunders, which is fine: you look at the moves it gives you and you see that you could have won a knight or your opponent could have taken your rook.

However, computers are very poor at giving strategic guidance, which is what most beginners really need.  Avoiding gross tactical blunders is mostly just a matter of practice (and, OK, it's plenty enough to win most games against other nine-year-olds). But, to get any farther, it's not enough just to play aimlessly but without blunders.

If you're an OK player yourself, you can probably offer much more to your son than any computer could. If you don't feel that you're a good enough player to teach anything much to your son, I'd say that your best options are to either both learn together (your greater intellectual maturity will help you structure things and choose what to do next; his greater ability to soak up everything like a sponge will help to push you both) or to enroll him in a chess club where somebody more experienced can take on that teaching role. If he's really keen, you could even hire a coach for him.

Thanks to JiK for a helpful comment that was edited into this answer.


CLI tool to let chess engines play each other I'm looking for a command-line tool to let two chess engines play a game or a tournament against each other. The tool should support UCI and/or the xboard protocol and it should allow to save the game as a PGN.

I could only find GUI programs for that purpose. Aren't there any commandline tools that can do that job?


Which variation of the Grunfeld Defense for White will lead to the most strategic and least sharp position? [fen ""]

1. d4 Nf6 2. c4 g6 3. Nc3 d5

After 1. d4 Nf6 2. c4 g6 3. Nc3 d5, which variation of the Grunfeld Defense leads to the most solid and strategic position? If possible, I prefer a variation with possibilities for a minority attack. The Exchange Variation (4. cxd5) is too sharp and contains too much theory. If possible, there should not be loads of theory.

Maybe 4.e3 is an interesting idea against the Grünfeld. Usually, black answers with 4....Bg7, but it should be noted that black can transpose to the Slav defence with 4....c6.

After 4....Bg7, white has two interesting options: 5.Qb3 and 5.cxd5.

5.Qb3 is probably the most popular continuation, attacking the pawn on d5. If black plays 5....dxc4, then white should be slightly better after 6.Bxc4. After 5....c6, a Slav defence-like position arises, which black players probably want to avoid. Therefore, 5....e6 is the most common response. Then, white can (temporarily) stop black from castling with the interesting move 6.Qa3!?, which has been played by several strong grandmaster like Nakamura (against Caruana), Ivanchuk and Dreev. After 6....Qe7?!, white obtains a clear advantage after 7.Qxe7+ Kxe7 8.b3.
The idea behind 5.cxd5 is to answer 5....Nxd5 6.Nxd5 Qxd5 with 7.Ne2 and 8.Nc3. This line has been played by several grandmasters, including Kramnik (in a rapid game against Svidler) and Andreikin.

Although my suggestion has some ideas and has been played by many grandmasters, it is far from the most principled continuation against the Grünfeld. Nevertheless, I believe it has some venom and could be a good try to surprise your opponents.

  [StartPly "7"]

  [FEN ""]
  1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 (4...c6) 5.Qb3 (5.cxd5 Nxd5 6.Nxd5 Qxd5 7.Ne2) e6 (5...dxc4 6.Bxc4) (5...c6) 6.Qa3 Qe7 7.Qxe7+ Kxe7 8.b3


Non chess specific game AI that learns any game and can play chess? There is another question that asks "Has anyone ever written a chess program that does have insights of its own" that question is about a chess only game AI. I am asking having to learn the rules of the game, pieces, board size, etc. The program should be able to learn any board game, checkers, go, etc. Computers programmed by humans are better at chess than humans. Any computer programmed by itself (via some self learning algorithm, where even the rules have to be learned, i.e. number of pieces, board dimensions, piece move rules, game objective, etc) playing any good at all? Let's ignore that the self learning algorithm would have been devised by a human...

If you know of any such generic game AI engines, please post references to them, at least their name. Thanks!

http://rebelscience.blogspot.de/2011/02/intelligent-computer-chess-part-i.html

This is the blog of a guy who tries to do what you describe: Create an artificial intelligence that learns to play chess purely by trial and error. I don't think he ever got very far. He also believes that the old testament contains coded information on how to create an AI …

It is surely possible to create an AI that learns to play chess from scratch, but I doubt it would ever be any good (Though this General Game Playing stuff doesn't learn the rules, the deepmind company atari AI does.). The reason is that chess is a tactical game and calculating tactics requires extremely optimised code. That's nothing you just stumble into after playing a few million games.


What is the reason (if any) for 1.e4 c5 2.Nf3 d6 3.Nc3? As title above, what is the point of playing 3.Nc3 (before d2-d4) after 1.e4 c5 2.Nf3 d6? Compared to the “normal” 1.e4 c5 2.Nf3 d6 3.d4?

[fen ""]

[Variant "Standard"]
[ECO "B50"]
[Opening "Sicilian Defense"]

1. e4 c5 2. Nf3 d6 3. Nc3 { Less common move } (3. d4 { Usual move })

It basically just stalls for a move before 100% committing to the open Sicilian. For example, suppose you were playing White and hated facing this Sicilian (1.e4 c5 2. Nf3 d6 3.d4 cd 4.Nxd4 Nc6). You could use the move order you described and after 3.Nc3, only play 4.d4 if your opponent doesn't play 3...Nc6. If they do play 3...Nc6, then go for some Closed Sicilian.

Also in online bullet some people have done the 3.Nc3 move order against me because it takes half a second to realize what's happening and then play 3...Nf6 instead of 3...cd.


Omega Gambit For white My question is about Omega Gambit.

[Title "Omega gambit"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1. d4 Nf6 2. e4 Nxe4

Is it too dangerous for white? what are the ideas for white? And what is the winning percentage for white? Is it still played among titled players?

Is it too dangerous for white?

Yes.

  what are the ideas for white?

Try to use your open lines and get good piece play, I suppose. Black is already better, though (up a central pawn with no weaknesses), so you shouldn't expect to succeed.

  And what is the winning percentage for white?

In my database it is 19%.

  Is it still played among titled players?

No, and it never was (I can find only 2 games where it was played by someone with a rating over 2200).


If there was a perfect play from both sides, but each player was allowed to do 2 moves every time, would white win? Imagine a game where players are allowed 2 moves instead of one. If there were perfect play from both sides, would White win?

This chess variant you are talking about is Marsellais Chess. I infer that you mean that White has two moves to start with. If this was so, White would have an advantage(a refined version of this variant gives White only 1 move on the first move to null the opening advantage). So White would probably win. However, this is not certain, as we have not written a sufficiently strong engine for this yet.


Scandinavian Defence queen e5 I'm new to chess (around 1000), and I like to practice the Scandinavian defence. I started to check the theory related to it, and I've never seen a single source talking about this queen move after Nc3.

[FEN ""]
1.e4 d5 2.exd5 Qxd5 3.Nc3 Qe5+

I guess it's a bad one, otherwise they would mention it. But why is it a bad move? I've been playing this since I started (unconsciously) and I see no particular drawback (I just need to be careful not to make my queen stuck).

I understand that this opening violates the rule of development, but I don't feel the late when I play it. I often find a way to harasa my opponent (maybe it's because of my low rank, it becomes more visible at high rank?). Here are 2 variants I often end up with. As you can see I develop as good as white and I have even the queenside castling (almost) ready.

When defending with bishop:

[FEN "eoui"]
1. e4 d5 2. exd5 Qxd5 3. Nc3 Qe5+ 4. Be2 Bg4

When defending with knight:

[FEN ""]
1. e4 d5 2. exd5 Qxd5 3. Nc3 Qe5+ 4. Nge2 Bf5 5. d3 Nc6

This is a bit trivial as an answer, but too long as a comment. You claim that you can develop "as good as White" but that is simply not true. White begins by interposing the Bishop 4.Be2. You play 4..Bg4. It is now a mistake to play 5.Nf3 because 5..Bxf3 spoils whites Pawns and makes his King insecure. But 5.d4! also gains a development tempo, and forces Black to choose one of the two moves that does not lose a piece.

If 5..Qe6, then I would choose 6.Bf4 from among many good moves. Then 6..c6 7.Qd3
and the contrast between positions is huge.

If 5. Bxe2, then Nxe2, with a similar outcome.

Perhaps you were only concerned about losing a tempo to Nf3 and forgot about d4? I think that White is close to winning. Even if not, you have a long and perilous defence to look forward to.


Why do you put a knight or pawn in front of a fianchetto bishop? I've been asked whats the point of blocking the bishop with a knight or a pawn and don't know how to answer. It seems like quite a strange idea to fianchetto and not as straightforward and logical as putting it on a natural diagonal such as on c4.

This is a typical Sicilian Dragon position.  The fianchetto Bishop controls the long diagonal which helps protect the King, by protecting the h8 square and providing luft, and attacks the opposing King.  The Bishop is able to control two center squares while one posted on c4 can only control one center square.
The Knight does currently obstruct the Bishop, but can move with devastating effect, Nxe4 uncovers an attack on the d4 Knight.  In lines where there is a Pawn blocking the Bishop, King's Indian Defense/Attack, the Pawn is pushed to release the Bishop or the Pawn is used for a kingside attack.  The Bishop is often in the way of the Rooks, but does still provide good defense for the King.

[fen ""]
1. e4 c5 2. d4 cxd4 3. c3 d3?! { (0.00 ? 0.75) Inaccuracy. Best move was dxc3. } (3... dxc3 4. Nxc3 Nc6 5. Nf3 e6 6. Bb5 a6 7. Qa4 Qc7 8. O-O Nf6 9. Re1 Ng4 10. Bxc6) 4. c4?! { B21 Sicilian Defense: Smith-Morra Gambit Declined, Dubois Variation (0.75 ? 0.15) Inaccuracy. Best move was Bxd3. } (4. Bxd3 Nc6 5. Nf3 Nf6 6. O-O e5 7. c4 Bc5 8. a3 a5 9. Nc3 O-O 10. Bd2 d6) 4... g6 5. Nc3 Bg7 6. Qxd3 Nc6 7. Bf4 d6 8. O-O-O Nf6 9. Bg3?! { (-0.24 ? -1.12) Inaccuracy. Best move was Qd2. } (9. Qd2 O-O 10. Nf3 Be6 11. Kb1 Qa5 12. Ng5 Ng4 13. f3 Bxc3 14. bxc3 Nge5 15. Nxe6 Qb6+) 9... O-O 10. f4 Qa5 11. Kb1?? { (-1.06 ? -7.19) Blunder. Best move was a3. } (11. a3 Nd7) 11... Nb4 12. Qd2?? { (-6.81 ? -12.80) Blunder. Best move was Qe2. } (12. Qe2 Nxe4) 12... Nxe4 { White resigns } 0-1

The Bishop plays a secondary role.  By controlling the long diagonal, it does support the attack.
By looking at Dragon games, especially Rxc3 sacrifices, you will find that the Bishop is excellent at attacking along the long diagonal.


What are the motivations behind pawn moves on a and h files? Sometimes when there are no clearly optimal moves, a computer or a human master player would push their pawns on a and h files (the edges of the board), for no clear reasons.  What would be the motivations behind such moves?

The question is extremely open, as these pawns may be moved for many reasons depending on the position you are facing. In a general sketch, you may consider five kind of a and h pawn moves:

To create some luft for the king, that is, avoid once and for all the back rank threats.

[FEN "r5k1/5ppp/8/8/8/8/5PPP/1R4K1 w - - 0 1"]

In this position, neither rook can leave the back rank, because if they do Rb8 for white or Ra1 for black are checkmate (this is called to have a weak back rank). For this reason, it is useful to move h4 for white or h5 for black, in order to be able to escape via h2 or h7 if the rook leaves the back rank.

To attack the enemy castled king, as opening the h file usually comes with dangerous threats of infiltration with the major pieces near the king.

[FEN ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 O-O 8. Qd2 Nc6 9. Bc4 Bd7 10. O-O-O Rc8 11. Bb3 Ne5 12. h4 {This is a main line in the Yugoslav Attack of the Dragon. The plan is to go full aggression on the kingside: blast open the `h` file, play `Bh6`, exchange bishops and continue `Qh6` with mate threats on `h7`. To parry all the threats that white will make, precision is essential, since many good looking moves are actually horrible blunders.}

To gain space, either by a further advance of an adjacent b or g pawn or by avoiding a piece to be pushed away by a pawn.

[FEN ""]
1. e4 c5 2. Nf3 g6 3. d4 cxd4 4. Nxd4 Bg7 5. c4 Nc6 6. Be3 Nf6 7. Nc3 O-O 8. Be2 d6 9. O-O Bd7 10. Qd2 Nxd4 11. Bxd4 Bc6 12. f3 a5 {This is a main line in the Maroczy Bind of the HyperAccelerated Dragon. With this move, black makes sure the `b4` advance that white wants to make is delayed at least for some moves. Moreover, as is seen in the following moves, this allows black's knight to get a comfortable home in `c5`, as for the moment he cannot be dislodged.} 13. b3 Nd7 14. Be3 Nc5 {And white will have to prepare his plan of gaining space on the queenside thoroughly.}

Another fact (credit to JiK for pointing it out) that encourages the move of an a or h pawn before moving the corresponding b or g pawn is that the former often do not leave behind as big holes (or any holes at all) as the latter. This is because the pawns on the edge on the board only protect one square on the 3rd/6th rank, and many times the bishop pawn wasn't moved and already covers it, or in the event of leaving a hole, the queen's knight's file usually is away from the main action, so it may not be very important (one should consider very carefully whether leaving a hole in front of one's king).

To defend against pins in order to drive away enemy pieces or to take away a concrete square from them.

[FEN ""]
1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. d3 Nf6 5. c3 d6 6. O-O O-O 7. Bb3 a6 8. Nbd2 Ba7 9. h3 {This is a main line in the Giuoco Pianissimo. With the last move, white avoids the unpleasant pin of the `c3` knight by `Bg4`. This also creates some breathing space for the king, but that is not the main idea behind the move. The reason it is played now and not a few moves before is mainly because you are prioritizing piece development.}

To preserve a bishop from getting exchange (credit to Dag Oskar Madsen for pointing it out). Usually bishops are slightly better than knights, and giving your opponent the bishop pair would require to play with extra care in the endgame.

[FEN ""]
1. d4 Nf6 2. Nf3 g6 3. Bf4 Bg7 4. e3 O-O 5. Be2 d6 6. h3 {This is a main line in the London system. With the last move, white gives the `Bf4` a retreat in the event of `Nh5` while keeping it on the `h2-b8` diagonal, helping to tighten the grip on the dark squares. The reason `Nh5` earlier (when white pushes `e3`) does not work so well is because it allows a chronicle weakening of black's kingside, and the reason `Nh5` does work if `h3` is not played is half-positional half-tactical.}

This last position is quite complex, if interested you may want to look at this link for some variations.

Conclusion:

It's important to bear in mind that every move should be useful, as you must contribute to the global synergy of your pieces in order to achieve a better position. Usually at master or computer level, when they do not find the optimal move (although the computer usually does) or placement for their pieces, they always tend to achieve some kind of positional advantage, and those listed above are mainly of this kind.

EDIT: Examples have been added and a fifth case has been added.


Shogi without Japanese characters (kanji) On Wikipedia all the rules of Shogi are described, but as a reference I find that the Japanese characters (kanji) get in the way and the explanation is otherwise very wordy and unconcise.  Is there an online resource that describes Shogi where kanji are not used or are only given as supplemental (instead of essential) information, or can someone give such a description as an answer?

Ideally the description would be as concise as possible and have diagrams where appropriate (board setup, piece movement).

I think a turn-based multi boardgame site called brainking supplies information which is close to what you want. http://brainking.com/en/GameRules?tp=69


A cool problem by Godfrey Heathcote I didn't get a thought of a better title :)

I am trying to solve a problem which is white to move and mate in 2 moves.

To be frank, I am not asking all problems here. On my own I solved more than 50 and stuck up in nearly 15 (don't worry I will not ask all here itself, I am still trying to solve them)

[FEN "8/qQ5p/3pN2K/3pp1R/4k/7N/1b1PP/8 w - - 0 1"]


Seeking GM-level coverage of a typical pawn structure I was wondering if there is a top level coverage of plans for Black in the below pawn structure:
[fen "8/pp3ppp/2p2p2/8/3P4/8/PPP2PPP/8 w - - 0 1"]

Or this one:
[fen "8/pp3ppp/2p2p2/8/2PP4/8/PP3PPP/8 w - - 0 1"]

I know similar ones arise from Caro-Kann, but have also seen it in many other openings where White plays Bxf6.
Computer claims equality, or a slight edge, but I would like to "hear an opinion" from top GMs if possible.

Vallejo has a great series (Spanish only) in chess24 about the Caro-Pirc, which covers this particular structure. Note that the dynamics of positions with those two pawn structures are probably very different from one another (a ...c5 break by Black would have a very different impact on each case. Similar ofr the pressure on the semi-open d file)
"Engine claims equality" does not make much sense when referring to the pawn structure itself, since many different factors will determine the actual evaluation of a given position.


Does 4.Ng5 in Two Knights Defense have a name? Just like the title says, is there a name for the line starting with 4.Ng5 in 1.e4 e5 2.Nf3 Nc6 3. Bc4 Nf6 4. Ng5 called?
Wikipedia article https://en.wikipedia.org/wiki/Two_Knights_Defense, does not give a name.
This Youtube video https://www.youtube.com/watch?v=rKoZkrBWDbU refers to 4.Ng5 as The Knight Attack, but I searched for it and I don't see other references to The Knight Attack.
Also, often people refer to 4.Ng5 as Fried Liver attack, which I believe is incorrect, since Fried Liver attack arises later in the game, after 1.e4 e5 2.Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 Nxd5 6. Nxf7.

I think the name for 4. Ng5 is Knight Attack. There isn't a specific name, because it leads to more specific openings, like the Fried Liver Attack, Polerio Defense 4. Ng5 d5 5. exd5 Na5 (trying to prevent the sacrifice), the Traxler Countergambit 4. Ng5 Bc5, and more. It's just like how 1. e4 e5 is called the open game. There isn't a specific name for it, because it will lead to more specific opening.


Are there illustrative examples where a conventionally "bad bishop" leads its side to a win? I was looking the Chess glossary and two words brought curiosity : bad bishop and big pawn. Where the later being the condition that occurs when you have a bad bishop. One thing i noticed was bad bishop was always defined on end game reference. I don't understand why? Can't you have bad bishop or a big pawn mid-game or relatively early game!(?)

 Found these images for bad bishop and big pawn on Wikipedia:

Hence, I wanted to know if there were any games where big pawn leads a chess player to victory (When enemy has a good bishop) at an international stage?
or rephrasing the above as "occurrences where bad bishop was more significant to victory than a good bishop?"

My understanding is that we call a bad bishop a "big pawn" especially in the endgame to emphasize the fact that the bishop cannot be considered a full piece in these situations. It can't move much. It is very passive. Having such a bishop is a long term handicap.

You are right, these situations can also occur earlier in the game, but there is always a hope that a passive bishop can be traded or become more active when the position opens.

For instance, in the Dutch Stonewall, the Bc8 is a bad bishop but you can try to trade it by playing Bc8-d7-e8-h5 or via a6 in some cases. Having such a bishop earlier in the game is a handicap, but calling it "big pawn" would be too definitive, the bishop can live again!

*"Occurrences where bad bishop was more significant to victory than a good bishop?"

In the early stages of the game this is very possible and I'm sure we could find examples in the Dutch Stonewall or in the French defense where the Bc8 wins the game. In the endgame, I guess this will only happen if the opponent makes a mistake to turn a bad bishop into a winner.

Here follows an example, where the bishop in e6 is a "big pawn". White could have taken advantage of that and won the game. But in the end, after White's mistakes, the "bad" bishop wins the game!

[Title "Max Euwe vs Vera Menchik, Hastings 1930/31"]
[fen "6k1/1p3ppp/4b3/2Pp4/8/4P1P1/B4PPK/8 w - - 0 1"]

1.Kg1 Kf8 2.Kf1 Ke7 3.Ke2 Kf6 4.Kd3?! (4.Bb3!! {Dvoretsky} 4... Ke5 5. f4 Kf5 6. Bd1! {arriving just in time to cover the g4-square} d4 7.Bc2+! Kg4 8.exd4 Kxg3 9. Ke3 f5 10. Bd1 Bd5 11. Bf3+-) 4... Ke5 5.g4 g5! (5... Bxg4? 6.f4 Ke6 7. e4 Ke7 8. Bxd5+-) 6.g3 Bxg4 7.f4+ gxf4 8.gxf4+ Kf6 9.Bxd5 Bc8 10.Bf3? (10.e4!?) Ke7 11.Kc4 Kd8 12.Kd5 b6! 13.c6? (13.Bh5=) Kc7 14.Ke5 Be6 15.f5 Bb3 16.Kf6 b5 17.Kg7?? (17.e4!=) b4-+ 18.Kxh7 Bc2 19.Kg7 b3 20.Bd5 b2 21.Ba2 Kxc6 22.f6 Kd6 23.e4 Bxe4 24.Kxf7 Bd5+! {The "bad" bishop in action!) 25.Bxd5 b1=Q 26.Kg7 Qg1+ 27.Kf8 Kxd5 0-1


How to write a simple chess engine to statically evaluate a position? I want to evaluate positions statically. So I've written a code which evaluates from a FEN string.

However it is a tedious to copy FEN and then paste for a complete game. So I wanted to know if it is possible to write such a code which can run with WinBoard and which could evaluate the current position statically.

It does not need to generate moves,be able to play a game, deep evaluation ,quiescent search etc.

I'm also not interested in performing King Safety/Mate Threats.

So the program should just give me only a number as output when loaded in WinBoard.

Is there a simple way to perform such a task or a simple enough engine I can modify to do this?

Why can't you just make a Winboard chess engine, but evaluate a position statically??

You will need to follow the Winboard protocol:

  https://www.gnu.org/software/xboard/engine-intf.html

Although everybody uses alpha-beta/nega-max pruning, but Winboard doesn't know your code. All you need to do is just give an evaluation score from your static function.

Your "engine" will wait for the go Winboard command. Print thinking output like:

  ply score time nodes pv

where score will be your static evaluation score. Your engine doesn't need to make a move, Winboard will wait forever for a move. You can always setup a new position in Winboard.


Probability of given position/piece configuration I'm currently working on an image based FEN generator. I found a paper doing the same and they have used Stockfish to  calculate  the  most probable piece configurations.
Now I wonder if Stockfish has this functionality or if they implemented it on their own. Does anybody know more about this, as it would be extremely helpful for my project?

On pages 7-8, the paper gives information on what they did.

Utilizing a chess engine: We utilized the open-source Stockfish engine, which  allows us to calculate the most probable piece configurations. By calculating the prob-abilities of all possible configurations, we could choose the most probable candidate (see Figure 7). Additionally, we strengthened this method by utilizing large-scale chess game statistics in the manner proposed by Acher and Es-nault Acher and Esnault (2016).

Utilizing a chess engine: We utilized the open-source Stockfish engine, which allows us to calculate the most probable piece configurations. By calculating the prob-abilities of all possible configurations, we could choose the most probable candidate (see Figure 7). Additionally, we strengthened this method by utilizing large-scale chess game statistics in the manner proposed by Acher and Es-nault Acher and Esnault (2016).

This makes literally no sense to me- SF is just an engine, and can't exactly give stats on most probable piece configs, and even if the researchers wrote some code to do such, it would be different than the most probable ones in human play.
My suggestion would be to use CQL on some database and search for each configuration.
Alternatively, SCIDvsPC (free) and ChessBase (paid, and quite expensive) can search for these sort of configurations as well, so you might want to use those.
As for what database to use, my recommendation would be Caissabase (free)