Central control disliked by engine in 1.e4 e6 2.d4 a6 3.c4 Recently I played a chess game that started with the moves: 1. e4 e6 2. d4 a6 and then I played 3. c4 which according to Stockfish is inaccurate.

[fen ""]

1. e4 e6 2. d4 a6 3. c4

What is the reason for that? How is this situation any different in essence from the King Indian defense for instance in which White occupies the center right away with 1. d4 Nf6 2.c4 g6 3. Nc3 Bg7 4. e4 ... ?

[fen ""]

1. d4 Nf6 2.c4 g6 3. Nc3 Bg7 4. e4

It's not inaccurate whatsoever. 3.c4 is just as good a move as 3.Nf3, 3.Nc3, etc. In general you should take what engines say that early on with a grain of salt, unless the position is already extremely tactical. What was the evaluation drop when you played 3.c4, and what depth was Stockfish thinking at? For me, at depth 27 Stockfish 10 goes down from 0.58ish to 0.48ish, which isn't significant on move 3.


What are the minimum required pieces for checkmate in 3d chess? Assuming the rules of millennium 3d chess, what are the minimum required pieces for checkmate?

I realize this is an extremely difficult question, but in regular (2-dimensional) chess, we have rules of thumb for when two players should draw during the endgame.

A few examples of these kinds of scenarios (in 3d chess) would be much appreciated.

The following are minimum involving various pieces:

King + Queen
King + Rook + Any Piece
King + 2 Bishop
King + 2 Knight

This is only the theoretical minimum to actually mate. Whether or not it is possible to force a mate in this situation is a different question. You can see these mates by placing both kings in a corner, one on board 1, and the other on board 3.


...e5 in response to the Keres Attack? TL;DR Has a quick ...e5 in response to the Keres Attack been well-analyzed somewhere?

Kasparov famously ditched the 5...e6 Scheveningen move-order for a 5...a6 Najdorf move-order during his 1984 match with Karpov, primarily so as to avoid problems against the Keres Attack, 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.g4 (at least that's how I remember the story being told in various accounts). I don't often see the Scheveningen move-order in top tournaments, but I recalled having seen Hou Yifan do so recently, and having faced the Keres Attack. For instance, in the 2012 Unive tournament, there is the interesting game Nakamura-Hou, won by White:

[fen ""]
[Event "16th Unive Tournament"]
[Site "Hoogeveen NL"]
[Date "2012.10.23"]
[EventDate "2012.10.21"]
[Round "3"]
[Result "1-0"]
[White "Hikaru Nakamura"]
[Black "Yifan Hou"]
[ECO "B81"]
[PlyCount "97"]

1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.g4 h6 7.Rg1
e5 8.Bb5+ Nbd7 9.Nf5 a6 10.Bxd7+ Qxd7 11.g5 Nxe4 12.Nxg7+ Bxg7
13.Nxe4 Qc6 14.Qd3 Ke7 15.gxh6 Bxh6 16.Bxh6 Rxh6 17.Qe3 Rh5
18.Rd1 Bf5 19.Ng3 Bxc2 20.Nxh5 Bxd1 21.Kxd1 Qd5+ 22.Ke2 Qxa2
23.Qg5+ Kd7 24.Qf5+ Ke7 25.Qc2 Qa5 26.Ng3 Qb5+ 27.Kf3 Qc6+
28.Qe4 Rh8 29.Nf5+ Kd7 30.h4 Qb5 31.Rd1 Qxb2 32.Nxd6 Kc7
33.Nc4 Qb5 34.Nxe5 f6 35.Rc1+ Kb8 36.Rb1 f5 37.Qxf5 Qd5+
38.Qe4 Rf8+ 39.Ke3 Qc5+ 40.Qd4 Qxd4+ 41.Kxd4 Rf4+ 42.Ke3 Rxh4
43.f4 Kc7 44.f5 Kd6 45.Ng6 Rh7 46.Rd1+ Kc7 47.Kf4 b5 48.f6 Rf7
49.Ke5 1-0

Despite that loss, at Wijk aan Zee 2013, there was the game Harikrishna-Hou, in which Black was the victor:

[fen ""]
[Event "Tata Steel"]
[Site "Wijk aan Zee NED"]
[Date "2013.01.23"]
[EventDate "2013.01.12"]
[Round "10"]
[Result "0-1"]
[White "Pentala Harikrishna"]
[Black "Yifan Hou"]
[ECO "B81"]
[WhiteElo "2698"]
[BlackElo "2603"]
[PlyCount "110"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e6 6. g4 h6
7. h4 e5 8. Nf5 Nc6 9. Bg2 g6 10. Ne3 Be6 11. Ncd5 Bxd5
12. exd5 Ne7 13. Qe2 Bg7 14. Qb5+ Qd7 15. Qxd7+ Nxd7 16. Bd2
Rc8 17. Bb4 Nc5 18. O-O-O O-O 19. h5 Bf6 20. Kb1 Kg7 21. Nf1
Bg5 22. Ng3 b6 23. Bxc5 bxc5 24. Ne4 Rcd8 25. hxg6 fxg6
26. Rh3 Rf4 27. Ra3 Rxg4 28. Bf3 Rf4 29. Rxa7 Rxf3 30. Nxg5
hxg5 31. Rxe7+ Kf6 32. Re6+ Kf5 33. Rd2 g4 34. c3 Kg5 35. Re2
Rdf8 36. Rxd6 Rxf2 37. Rxe5+ R8f5 38. Re3 R5f3 39. Re5+ Rf5
40. Re3 R2f3 41. Ree6 Rf6 42. Re5+ R3f5 43. Rxf6 Rxe5 44. Rf1
Rxd5 45. Kc2 Rf5 46. Rg1 c4 47. Kd2 Rf2+ 48. Ke3 Rxb2 49. Ra1
g3 50. Kf3 g2 51. Kg3 Rxa2 52. Rb1 Kf5 53. Kh2 Ke4 54. Rd1 Kf3
55. Rd6 Ra5 0-1

After both Nakamura's 7.Rg1 and Harikrishna's 7.h4, Hou immediately makes a second move with the e-pawn, turning her Scheveningen small center into more of a Sveshnikov/Kalashnikov structure. I guess this makes sense, despite the slight loss of time, since Black is responding to White's early kingside action by switching gears and staking more of a claim in the center. And as someone who sometimes plays things like the Kalashnikov, I find this approach intriguing.

So finally, my question:

  Has this ...e5 approach against the Keres Attack been the subject of any GM-level analysis? If so, where? And what are the basic conclusions?

Sorry, not precisely a GM analysis of this line, but

I have found chessgames.com to be useful in this regard. Scroll down in the link, there may be some GM analysis in there. :)
http://www.chessgames.com/perl/chessopening?eco=b81

Also
http://www.chesspub.com/cgi-bin/yabb2/YaBB.pl?num=1309987842/0


Coordinate-style move output from chess engine, to control robot I'm using gnuchess to decide which move a program should make, and I'm using its output to control a robot arm (to execute the move on a real board).

However, gnuchess outputs SAN (Standard Algebraic Notation), such as "Nf3". To control the robot arm, it would be much more helpful to have a coordinate-based notation, such as "g1-f3".

My question is:

Is there a way to get gnuchess to output coordinate-based notation? I know it can accept such notation as input (human-supplied move).

-or-

Is there existing software (or detailed algorithm) that takes
 (a) a SAN move
 (b) a .eps board
and produces:
 (c) a coordinate-based move?

I use Linux, and here is how I get gnuchess to make its (SAN) move recommendation:

Use gnuchess to decide on next move.

reads current position from file named $1 (.epd format)
decides what move to make (as white), using gnuchess
prints out move
also stores resulting board in dgt.chess.nextpos (.epd format)

rm -f dgt.chess.nextpos

printf "solveepd $1\nepdsave dgt.chess.nextpos\nquit\n" |\
gnuchess |\
grep -a 'My move is' |\
sed 's/My move is : //'

I don't know how you would do that in gnuchess, but you could do little programming yourself in Python. This Python package would do that for you. It's main page has what you want:

>>> board.push_san("e4")
Move.from_uci('e2e4')
>>> board.push_san("e5")
Move.from_uci('e7e5')

You have the move string and chess board. It shouldn't be hard for you.


Is there any free software to automatically analyze and annotate games? I'm looking for free software that automatically analyzes and annotates chess games (post-mortem), preferably marking blunders, suggesting good alternatives, pointing out missed tactics (forks, pins, skewers, removing the defender, etc.). Preferably it should also generate some printable output (e.g. PDF) so one could ruminate away from the computer, and in front of a chess board. What do you guys use for this?

Chessbase will do what you're describing (enter the game, then tell it to annotate), but it is not free.

Scid is a free alternative database program, but it will not automatically annotate your game.

See here for more discussion: http://www.chess.com/forum/view/general/is-there-any-free-software-to-analyse-the-completed-game


Josh Waitzkin on trading pieces ('the art of the trade') Based on: Josh Waitzkin Chessmaster Strategy Section 6 "The Art of the Trade." A video can be found here.
[Event "From Josh Waitzkin Chessmaster Strategy Section 6 'The Art of the Trade'"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "-"]
[Black "-"]
[Result "*"]
[SetUp "1"]
[FEN "r2q1rk1/p4ppp/1p2p3/2p5/2Pp4/PP1Pn2P/3QPRP1/RN4K1 w - - 0 1"]

1. Nc3

Situation

Josh says "2 possible solutions" are a4 and Qc1. Technically, he doesn't say they are the only possible solutions.

My thought is to play Nc3 in this position. The chess.com says engine says Nc3 is the best (as in not unique) move.

Actually, I probably would've done something like b4, but Josh really said that one has to calculate several moves ahead. So, after some deep calculation, I came up with Nc3. I figure the idea is that you realize that black's knight has only 1 defender and then you calculate this counter-intuitive move of seemingly hanging your knight to see if you can really pull off this knight exchange (if black were to attempt to exchange), among others.

It turns out Josh didn't even seem to do calculations with either a4 or Qc1. He just laid out plans assuming Black wouldn't make any move.

Questions:

Actually, is Qc1 is merely "good"? 3 of the best moves that the chess.com engine says (either by saying the move is best or by telling what is an alternative) are Nc3, Qa2, and a4. Is Qc1 strictly inferior to Nc3, Qa2, and a4, and, so, Josh is actually wrong here to prefer Qc1 to a4?

1.1. Josh says a4 weakens white's pawn structure. Good point, but I don't know. The engine says Qc1 is just 'good'.

1.2. Well I think the only 2 queen moves here are Qc1 and Qa2. I guess Qa2 is more active than Qc1. I don't know.

1.3. Another thing to note: Maybe Josh mistakenly said Qc1 instead of Qa2. After this correction, perhaps we can then talk about a4 vs Qa2 and then say Qa2 is better.

Wait so what exactly is the calculation here? I was expecting we do (WOLOG the Qc1 thing) Qc1, think of black's move, do a response, etc. In the end Josh just showed how the white knight could go Nd2 to Nf1.

Since you explicitely requested an answer...
I don't own that Waitzkin book, but merely judging from your excerpts his pedagogical talents are as doubtful as White's position here :P
First of all, Black might cement in his octopus on e3 with e5, f5, f4, after that an exchange on e3 makes White's plight only slightly better. Insofar your 1.Nc3 makes very much sense, since Black is a move short for the above plan now. But tactics always trumps strategy (which is what Waitzkin misses to highlight - also your other question, which you asked me to contribute on - maybe later :-) - is highly tactical in nature), and the critical line is of course 1...dxc3 2.Qxe3 Qd4. White won't exchange since a protected Pc3 would be a disaster in the endgame. So, 3.Qc1 a6 (Black wants to cement with b4 then) 4.a4 b5 5.cxb5 axb5 6.axb5 Rxa1 7.Qxa1 c2! 8.Qc1 Ra8!! 9.e3(!) Ra1!! 10.exd4 Rxc1+ 11.Kh2 Rh1+! 0-1. This line might have more holes than an Emmentaler as I calculated it even without a board (and 2350 was my ELO 30 years ago...), but it should show you the tactical dangers after 1.Nc3. It might thus well be that objectively White must grin and bear it and play Qc1,Nd2,Nf1 and play possum awaiting the incoming pawn storm at the kingside. a4,a5,axb6 exchanges a rook but then only Black invades the queenside (as long as the Ne3 is present, the Rf2 is factically out of play).
Lessons learned: If a GM says "play X", it might be he has subconsciously calculated a lot of Y that is quite as relevant as long-time positional considerations. And you rarely find those lines explicitely in a textbook. ("Hey, why should I axe trees for the lines after Y? It obviously loses after 10 moves!")
P.S. I wouldn't play White even if Waitzkin gave me five quids :-)


Blindfold game records of chess and xiangqi According to Wikipedia,  Timur Gareyev played 48 opponents with a mask before his eyes and sitting on an exercise bike, resulting in 35 wins, 7 draws, and 6 losses. On the other hand, the record for blindfold xiangqi is only 26 opponents. It seems that it is extremely difficult to improve this record even by one game.

I am wondering what makes the difference in the number of opponents? I do not think it is because xiangqi is more complicated than chess.

It could be as simple as the relative popularity of playing blindfolded. In chess playing blindfolded goes very far back. There are reports of islamic scholars playing blindfolded chess of three games simultaneously more than a thousand years ago. In modern times blindfold exhibitions have been a staple of chess events. As records tend to be improved in small steps, maybe xiangqi just didn't have enough events of this type yet, to get to a similar number of games.


Is there a good example of a paper chess book converted to an ebook? With Epub, or other ebook formats, one can take advantage of the format and do things that are difficult to do in a paper book. Hyperlinking, extra diagrams, more page breaks - what else? Most books for kindle I can find on amazon have been "converted" from paper books, but have identical content to their paper counterparts. Is there a good example of a popular/good chess book that is much easier to study on electronic device?

It depends on what you mean by an "electronic device", but there has been ebook versions of chess books for quite some time, from publishers like Everyman, although admittedly these are nothing like regular ebooks. Of course your device must be capable of running CB reader or an equivalent that can open the chessbase format files.
On the more practical side of things, chess books don't sell very well and formatting even the printed copy is a lot of work. QualityChess has no intention of producing ebooks that can be easily copied:

Q: Will your books be available as pgn or ChessBase e-books?
A: As long as it is easy to copy these forms of readers, it makes absolutely no sense. Why other companies choose to do this is a mystery.


New chess variant (opinion required) I have just came up with a new chess variant.
The variant works like this.
So, the player starts with a match with a computer (not-so-powerful one)
If the player wins the match, he gets to use the computer as his advisor.
And then, the player, with the new advisor goes up the ladder and challenge a more powerful computer. And so on and so forth.

What do you guys think about this variant? Will this give the human player an advantage? Do you think that the World Chess Champion can win the Best Chess Program (Stockfish) using this system?

I have got this idea from a chess match of GM Daniel Naroditsky+Rybka vs Stockfish match. IMHO, the computer has already won the human-computer chess rivalry. But if human players can subdue weaker chess computer and then use them against stronger computer, it would be another way of saying that human can still beat computer.

Principally I like your idea. I really like it. I could even imagine to implement something like that just for fun sake. However, there are some problems:

At a certain stage, an average player with a strength of about 1400 will just end up copying his engines moves in an extremely tactical position, which he doesn't understand.
If there is an ELO difference between the engines of only about 50 points (what's pretty common, especially in the higher levels), one could easily win by luck (since a higher ELO doesn't necessarily mean a 100% win chance) or even by just playing as white. This issue however can be fixed by giving opponents with about 200 ELO more, so one's not going to win by his engine itself.
Humans usually rather play with other humans, since they're more predictable. An average machine sees almost every trap in one or two plies, while humans may overlook it. "Playing for tricks" is essential, especially in quicker time controls.
One might struggle to proceed further at a certain level. It's unterstandable, that it becomes boring to play (and lose) to the same engine over and over again.

Sorry for my bad english, I'd appreciate any suggestion. (:


Deleting multiple games from a large PGN file I have spent around half an hour searching Google and I have not found what I am looking for -perhaps I did recognise it as what I needed if I had come across it. I have just recently downloaded SCID and decided to add all of my games from Chess.com as a starter to a database.

After combining all the separate PGN files into one, I used the utility that comes with SCID to convert it into the SCID database format. Along with the output of that utility is a file -.err format- of errors -if any- that occurred during conversion. While the number of errors I got is not much, it is large enough for it be a complicated process if I went through and deleted the games by hand.

An example from the first three lines of the error file (1 game):

my_games.pgn:(game 383, line 10658) Error: Invalid FEN: rnqkrbbn/pppppppp/8/8/8/8/PPPPPPPP/RNQKRBBN w EAea - 0 1

my_games.pgn:(game 383, line 10658) Error reading tag: [FEN "rnqkrbbn/pppppppp/8/8/8/8/PPPPPPPP/RNQKRBBN w EAea - 0 1"]

my_games.pgn:(game 383, line 10663) Error reading move in game graffitivisuals - walidmujahid, 2012: Ng3

Is there a utility out there where I could simply pass my PGN file though it and specify the game number -multiple- to delete. I am still new to SCID, so perhaps did I miss the fact that SCID has something that can help with this matter?

Any guidance on this would be most appreciated.

Post Script: GitHub was among the places that searched for such a utility, though, without fruition. If, perhaps, there is a script that comes remotely close to doing what I described, or perhaps even does exactly what I need, any guidance towards that script would also be most appreciated.

Maybe use the free Chessbase Reader and import/open the file. That might work.


Is chess a good game to fight against gambling addiction? I read a couple of poker books and I thought I could win, which was not the case.

Fortunately for me I have a decent chess level, 1930 in rapid, and I simply changed poker books for chess books and returned to the club. I have not lost a lot, but I realized if I don't win money why play something I enjoy less than my favourite game since I was a child.

As the game is helping me not to gamble, I wonder if it is documented from a medical point of view similar cases where chess helped.

I have seen plenty of people, who are addicted to chess, as it can become very time consuming if you take it seriously. So yes, it could easily help people swap an addiction that most would see as potentially more detrimental for one that is more healthy.


What was Fischer's preparation for tournaments? Surely he didn't follow the old cookie-cutter formula of take a day off before game day, play blitz matches, or some other standard ritual?

Any sources?

This is a question for people who knew him well personally. Anyway Fischer lived and breathed chess almost daily since the day in which he learnt the rules, until well into the first match vs. Spassky, so we have no reasons to believe that he changed his lifestyle before tournaments, i.e. he constantly played and studied chess, at least until his life's main mission changed and became the one to "unmask the Jewish conspiracy". But this happened after the first match vs. Spassky. However it is evident that the mature Fischer was aware of the importance of being fit physically, so we have to suppose that he did some exercise, especially before important matches and tournaments.


Why the extra rank on each side in 4 player chess? Why do we have an extra rank (the red lines below) on each side in 4 player chess on? What could be the possible logic?

(screenshot is taken from chess.com)

As SmallChess notes, the rook pawns would be able to capture on the first move. That in itself wouldn't be a problem, since the player can just capture back, but then we have a situation with two half-open lines where the pawns are pinned against the rooks behind them. That's a lot of tension already after the first move, and on the flanks, which is quite rare in normal 1v1 chess.

I'm not sure how to visualize this, but if red takes the blue pawn, and blue responds by capturing with their rook, yellow's king's rook pawn is pinned by the red rook (and attacked by the blue pawn) and green's king's rook pawn is pinned by the blue rook (and attacked by the red pawn).

@RemcoGerlich notes another very early possibility for two players to gang up on the last player, by capturing two of their pawns on the first move. Perhaps this is part of a general problem with 4 player chess...


What are the latest ideas for Black against the Samisch King's Indian Defense? I am always afraid of the Samisch variation of the King's Indian. It's the main reason why I switched to Chebanenko Slav (or ..a6 Slav, or Kamsky's Slav). But my opponents seem to be always prepared against the Slav. So after few months of unsuccessful Slav, I am going back to King's Indian Defense.

[fen ""]
[StartFlipped "1"]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6. Be3 Nc6 7.Qd2 e5 8. d5 Ne7 9. Bd3 Nh5 10. O-O-O f5 11. exf5 gxf5

After gxf5, Black's position is scary.

Thanks!

According to the Game Database of ChessTempo, after 6.Be3, there are 3 main variations:

6....e5: 1970 games
6....Nc6: 1651 games
6....c5: 1335 games

After 6....e5 white's main moves are 7.d5 and 7.Nge2. After 7.d5 black has two options: 7....c6 (counterplay on the queen side) or 7....Nh5 8.Qd2 f5 (counterplay on the king side). After 7.Nge2 black's most common move is 7....c6.

After 6....Nc6 the most popular move is 7.Nge2. After 7.Qd2 black often plays 7....a6 (the very best move in my opinion), and black seems to have excellent results after 8.0-0-0 (simply too dangerous in my opinion) with 8....b5 or 8....Rb8. The main line 8.Nge2 Rb8 actually transposes to 7.Nge2 a6 8.Qd2 Rb8, leading to a complicated position, where black has 2 plans: b5 or e5.

After 6....c5 black should be ready to play

the pawn sacrifice after 7.dxc5. The statistics in the database suggest that black has enough compensation for the pawn.
the Benoni positions that arise after 7.d5 or 7.Nge2 Nc6 8.d5.

In order to make a choice between these 3 options, you can search some games of strong players to see which type of positions suits your playing style the most.

      [FEN ""]
      [StartPly "11"]

      1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 Nc6 (6...c5 (7.dxc5)(7.d5) 7.Nge2 Nc6 8.d5) (6...e5 7.d5 (7.Nge2 c6) 7...Nh5 (7...c6) 8.Qd2 f5) 7.Qd2 (7.Nge2 a6 8.Qd2 Rb8) 7...a6 8.O-O-O (8.Nge2 Rb8) 8...b5 (8...Rb8)


Stretching the tournament rules, re: capturing pieces Building on this question about tournament etiquette:
What is the etiquette (or tournament rule) for the act of capturing a piece?

Suppose I want to capture a piece but am not sure which of my pieces I'd like to capture with. Is it legal to remove the opponent's piece from the board, then think for 15 minutes before completing the move (i.e., placing my chosen piece on the square previously occupied by the enemy) and pressing the clock?

I know it's probably disconcerting to my opponent (and not good etiquette). I wouldn't do this intentionally. At this point I'm just asking about legality.

Your opponent has the right to view the board also when it is your turn. If you did this and your opponent complained to the arbiter after a minute or two you would face sanctions. Probably just a warning for a first offence, then a time penalty and if you continue repeating the tactic eventually you would forfeit the game. This loss would be graded as such.


Is 1. d4 Nf6 2. Nf3 e6 3. c4 d5 called Queen's Gambit Declined when there is no gambit offered, let alone declined? I understand that the opening 1. d4 d5 2. c4 e6 3. Nf3 Nf6  is called Queen's Gambit Declined. But how about 1. d4 Nf6 2. Nf3 e6 3. c4 d5? There is no gambit offered, let alone declined. Is it still called Queen's gambit declined?

Yes, it is still called the Queen's Gambit Declined. That's just the name of the system, regardless of the move order used to reach it. However, it is not the QGD before Black chooses to push 3...d5.


Cancel match chess online If I played chess online, there is an option to cancel the match. Does official chess game allow it or what rules define it?

You can't cancel the match once it is started. Your only option is to resign in such case.

You're referencing something called "abort" where the match is ended with no result for either side. There is no option to "abort" in modern competitive chess, but it is worth mentioning that a few decades ago it was the norm to adjourn games that took an unreasonably long amount of time (i.e. played long into the night). It would be resumed at a later time convenient to both players.


AlphaZero and the revenge of the Artificial Intelligence Answering this question, @SmallChess offered this answer:

  Before Google's chess journey, the chess engine community believed:
  AI chess will not beat classical programming because neural networks
  (or other models) run much slower.

I was looking for a reference to this quote. Did someone make this
prediction in the past?
I have another, perhaps more fundamental question related to another part of @SmallChess' answer:

  AI machine learning is not new to chess. There were serious attempts
  before Google established. Unfortunately, nobody had the
  determination, skills and resources to do a good job.

Is it possible to pin down precisely what they have done better than others? Could it be simply that they use a lot more of computing ressources than before?

Subsidiary question: For a layman, who doesn't know how to compare TPU
    and CPU, instead of 4 hours, how long would Alphazero's training
    have taken with Stockfish's configuration? (44 threads on 44
    cores - two 2.2GHz Intel Xeon Broadwell CPUs with 22 cores instead of a single machine with 4 first-generation TPUs. See
Supplementary Materials for    their Science paper.)

Pretty much everybody. The reason being that it is STILL slower. The evaluation function for alphazero has WAY more variables so despite more computing power, alphazero can only calculate a fraction of number of positions than stockfish. However the evaluation function for alphazero is much much better due to self-learning and also takes forever to calculate.

https://arxiv.org/pdf/1712.01815.pdf

Consider this. Google used 5000 super computers to train the AI to play before the game. Now consider what happens if you give stockfish access to 5000 super computers to think for 4 hours and if it memorized all those lines.

The issue comes down to computing power.
Not in your lifetime.

It is a bit difficult to find Ghz to tflop conversions but consider this.

https://www.pugetsystems.com/labs/hpc/Intel-Core-i9-7900X-and-7980XE-Skylake-X-Linux-Linpack-Performance-1059/

28 cores on 2.6Ghz gives about 1.123Tflops. So for 88 cores running at 2.2Ghz each is around 3Tflops. So your system gives around 3Tflops.

Now I can't find any information on the first generation TPUS but the second generation TPUs have 180 Tflops each.

https://en.wikipedia.org/wiki/Tensor_processing_unit

So 1 TPU = 60 of your systems. So 5000*60*4 = 1200000 hours = 136 years.

Also should clearly show how unfair the alphazero vs stockfish match is.

Edit: I made a mistake, you said 2 22 core systems. My calculations had 88 cores. So you would need to double the previous total to 272 years.


What are the options for solving puzzles online and tracking progress? I am looking for an advanced set of puzzles and the ability to track progress, similar to chessok (which looks good, but is not free, and the selection of puzzles is limited compared to their offline courses). My skill level is >2000 ELO. Are there any alternatives to Chessok?

ChessTempo allows for unlimited solving of tactics problems with a free membership. It has a large database of problems drawn from games, and it tracks your solving statistics along with your individual tactics rating. Also, you can track your progress on two sorts of problems: untimed, or where the elapsed time for solving factors into your performance rating.


Question on promoting pawns to queens If you have two queens (original and one promoted) on board and the original queen is captured....can you promote your next pawn at the eight rank to queen again?

Yes, you can.

Fide rules 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.
This is called the square of ‘promotion’. The player's choice is not restricted to pieces that have been captured previously. This exchange of a pawn for another piece is called promotion, and the effect of the new piece is immediate.

(bold by me)


What should the practical meaning of "blunder" be? There have been questions about the reliability of computer evaluation, and famous cases in which computers miss-evaluate positions have been given. What I want to ask is more related to the practical aspect of the evaluation, rather than its effectiveness.

As humans, we may find moves that put our opponents in deep trouble, or lead to positions we may personally enjoy, even though computers may label this moves as blunders. A classical example is Tal's knight sacrifice in the sixth game of their match. Humanly speaking, the move may be considered brilliant due to the creative inspiration it shows, and the practical effects of it (for the position gets complicated and rich in tactical motives, in which Tal felt comfortable). To a computer, though, it is disastrous; artificial intelligence can not feel discomfort nor prefer certain positions above some others, and quickly finds the correct refutation to the sacrifice.

In a practical sense, for a player looking to eliminate blunders (which is a goal dictated to many beginners), what does this actually mean? Is it correct to label as a blunder all refutable moves that severely worsen one's position, as engines do? Or is it more appropriate to use the word blunder in a more pragmatical sense, by referring to refutable moves that severely worsen one's position, and whose refutation can be actually achieved by a human opponent? In other words, how pure should the concept of blunder in chess be?

I know the question is somewhat philosophical, and I do not expect definite answers.

The definition of the word is rather subjective, since it depends on how much you value objectivity vs practicality. I think it seems reasonable to take both aspects into account. For example, a move that gives up a pawn on the spot (and offers no compensation) could be considered a blunder. Objectively it's clearly a poor move, and practically it's easy to refute: the opponent just takes the pawn, and that's the end of the story.

Meanwhile, a move that objectively loses 2-3 points, but forces the opponent to play 10 difficult moves in a row in order to exploit it (and if they don't play these moves, they will be much worse), may be considered "interesting" or "dubious". Objectively the move is even worse than the previous example, but practically there's a high chance it will work.

Judging the practicality of a move also depends on the time control of the game. In a blitz game, you can get away with a lot more than you could in a long OTB game. But you could also get away with a lot more in an OTB game than you could in a correspondence game with engines. The example above with giving up 2-3 points would definitely be labelled a blunder in correspondence.

So all in all, a blunder could be considered a move that is clearly objectively bad, but also rather easy to refute in an actual game.


The number of nodes from your perft results is identical to Stockfish (1486), so I think your implementation is correct.

How you report the individual moves is unimportant. The format is not part of perft, you can report it any way you want, Stockfish can do it anyway it wants. There is no standard. There is no rule that you have to report the root moves or the leaf nodes. This is implementation defined. In my own implementation, I'd just report 1486.

You just need to get the number correct.


Chess tactics software which can read files Lichess publishes tactics problems which can be downloaded from database.lichess.org.
The file is in csv format. Which software can be used to read and play positions from this csv file?

The format of the file is described here. According to this, the name of the columns are: PuzzleId, FEN, Moves, Rating, RatingDeviation, Popularity, NbPlays, Themes, GameUrl.
I do not know of any software to deal directly with this type of file. But (I see you're a software engineer) it's not difficult to write a snippet to convert the csv file (mainly columns FEN and Moves) to a pgn file that could be opened with any chess database manager.


Go for an isolated pawn I am having trouble deciding whether I should allow getting an isolated by pushing d5. For instance, this is one of many such positions:

[FEN "rn1q1rk1/pp2bppp/2ppbn2/8/2PP4/2N2N2/PP2BPPP/R1BQK2R w KQkq - 0 1"]

Right away, I can tell that I control more space with such an advance, and I also force my opponent's light-colored bishop to retreat.

Furthermore, I get another open file, but still that does not convince me.
In theory, the isolated pawn should enable me to have a dangerous attack on the kingside but my bishops are not occupying any terrific squares. Another reason which deterred me from playing d5 is that this pawn would become very vulnerable.

After forcing the e6 bishop to c8, I think that I am only forcing Black to fianchetto their bishop, which would exert pressure on the isolated pawn.

All in all, I am not sure how to tell which factors outweigh the others in the push of the d5 pawn so I can decide if such move is correct or not.

Your understanding and judgment about a couple of things is way off.

First, you really need to understand that all isolated pawns are not created equal. If it were on an open file, then you need to worry about it becoming a weakness more (frontal attack by rooks, in particular), but here, because after d5 cd; cd it is shielded by the pd6, it is hard for black to attack d5, let alone win it. Also, again, you are mistaking the famous "isolani" positions, which is an isolated d-pawn on the open file, which can often go to d5 and create k-side chances. This is not that position. This gains space, which in some types of positions can lead to an attack if the center is closed, but here, although I like d5, there are too many open lines in the middle to hope that a k-side attack will work.

I like d5 because it gains more space, and you will have the excellent d4 square for the Nf3 after you finish developing a bit more. That is a tangible and relatively permanent plus in your position.

If you do not do it now, black should play d5, and the position is closer to level. It is now, or never, and you are not losing anything on your development because black has to move the B twice also.

Positions like this typically will come down to who can seize the e-file. Even though the c-file is also open, in practice, it is not as important as the e-file. If you can double rooks, and black cannot oppose them, often due to his pieces tripping over each other in the lack of space, you will win. Also, then, and only then, you may be able to execute that k-side attack with Re3-g3 or h3.

Also, after d5 cd; cd, there is no really good square for the B to go to. c8 undevelopes it, d7 and the Q or N also want that square. f5, and Nd4 will come with tempo. g4, and white will play h3 and either gain the B pair, or at least gain luft with tempo.

Lastly, I also noticed that black's q-side will be vulnerable after the B goes to e3. For the Ra8 to move, then a6 will need to be played, and then maybe Nc4-b6 might happen. Also, if Na6-c5, black might try to secure the N with a5, and then b5 could lead to something.

All, and all, as a Master for 34 years, I really like d5.

The following is in response to the question below. It was too long to just add in as a comment.

First, let’s discuss the idea of Bc8 with b6 and Bb7. It is very bad for the following reasons: You are talking about spending three moves to reposition the B to b7, and you weaken c6, which white will get to soon. Nd4 supported by an eventual Rc1, and then the N will go to c6 severely cramping black. A white Nc6 will be absolutely intolerable, so you will be forced to spend yet another move to trade the Bb7 off for it. This will create a strong passed pawn for white on c6, and it will then expose the black pd6, which will then be on an open file, and possibly give white use of d5 for a piece, although there is no immediately good piece that could go there. Of course, white will not play Nc6 until he is sure that it will not simply be lost. In addition, all these moves are sure to put you way behind in development.

This Nd4-c6 idea protected by a pd5 is a very common idea, and compare it to Yusupov-Kuzmin 1981 (PGN below). Go through that game around the move 15.Ne5. The threat of e5 forced black to take drastic measures, but try to make other reasonable moves, and see just how much that N hinders black, and look at what happens when he takes it because he cannot tolerate it. Neither is a good option.

I do not like the B going to g4 because as white I am happy for you to trade it off on f3 giving me the two Bs. Also, if I do not lose a tempo playing h3 (“luft”, which is German for air, meaning you will not be able to backrank mate me later), which will probably be helpful later, that is another small plus. Chess is a game of accumulating small plusses at least when playing similarly-rated opponents. I am also a very positional player, and like closed and semi-closed positions, so that type of position is right up my alley. I am willing to make your position uncomfortable, and wait for you to crack.

This game comes from the 11/26/2008 version of ChessBase.

[Title "Artur Jussupow-Gennadi  Kuzmi, Moscow, URS Team Tournament-ch15 Final A Tournament, 5/16/1981"]
[FEN ""]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Nf3 O-O 8. Be2 c5 9. O-O Nd7 10. Bg5 cxd4 11. cxd4 Nf6 12. Qd3 b6 13. Rac1 Bb7 14. d5 Qd7 15. Ne5 Qd6 16. Nc6 Qd7 17. e5 Nxd5 18. Nxe7+ Kh8 19. Bf3 Rae8 20. Rfd1 Rxe7 21. Bxe7 Qxe7 22. Bxd5 Rd8 23. Qb3 Bxd5 24. Rxd5 Rxd5 25. Qxd5 Bxe5 26. g3 Bd6 27. Qd4+ Qe5 28. Rd1 1-0


Capture the c-pawn, so the opponent has an IQP but improved development, or let them push the c-pawn and form a queenside majority? This dilemma occurs in a variety of positions.

[FEN "r1bq1rk1/pp1nbpp1/5n1p/2pp4/3P3B/2NBPN2/PP3PPP/R2QK2R w KQ - 0 10"]

Here, it's white to move, and white has to choose between:

capturing black's c5 pawn, giving black an isolated queen's pawn, but we improve black's development with tempo,
make a developing move, thereby allowing black to play c4 on the next move, which creates a queenside majority of pawns, and can be dangerous later in the game.

This position is from Vasile vs. Voiculescu, where white chose to play a developing move (Rc1), and subsequently resigned after black eventually promoted the c-pawn.

Examples of famous players facing similar dilemmas: Short; Dreev; Giri.  They have different positions and make different decisions.

Question: How do we decide whether we should do 1. or 2.?

Here, I don't simply mean in this specific position.  I'm seeking general guidelines (or rules) as to when it is better to take, and when it is better to not take.

A few general guidelines:

Take if your opponent has to waste a move to recapture. Normally this happens once your opponent has moved the f8/f1 bishop. In the position you posted, Black can take back with the knight and continue developing.
Don't take if you've got a powerful position and are planning some aggressive attack. An attack often requires a good structural foundation in the centre, so taking on c5/c4 would compromise that.
Take if there are a few pieces exchanged off, since your opponent's extra activity from the IQP will be less dangerous without many pieces. Take especially if the queens are off, or if your opponent is missing their dark-squared bishop (assuming your opponent is playing Black).
Take if your opponent is behind in their queenside development. Undeveloped pieces ==> less activity ==> less danger from an IQP.
Don't take if your king's position is compromised. The last thing you want with a vulnerable king is to have your opponent get more activity for attacking.

These rules don't always work, but it's useful to take them all into account before making a decision.


How does one memorize a chess game? I study games from books, and would like to retain some of them in my memory, especially the opening part. I also want to remember my own games (I play about 5-10 tournament games - mostly against >2000 ELO rated players, and some rapid ones here and there). Are there any particular techniques or tips?

In my experience, memorization of chess games simply came from improvement. I first realized that I could remember the games of past tournaments when I was around 1600 ELO, and as I improved my visualization became sharper and I could recall games played years ago. My advice to you is to have the games notated and not just read, but play through them regularly. This repeated process of playing the moves of a game will help you retain the information necessary for you to recall the game in the future.


Are score sheet booklets allowed to be in use? Is it allowed to use a score sheet booklet for notations (with a recording of previous games), as opposed to a single "stand alone" sheet?
Reasons for not allowing this may, of course, be due to the possibility of cheating, for example, by having opening line reminders on previous pages and making use of them during the game. On the other hand, one may also have such notes in one's pocket, and I don't believe there's a prohibition against this, only against the usage thereof.

According to an annotated version of the FIDE rules, it's banned in some tournaments, which presumably means it's not banned in all tournaments.  The relevant annotation says:

  Article 11.3.1 has resulted in some tournaments banning the use of scorebooks.  Where these are allowed arbiters should ensure that players do not refer to earlier games.

I've never played in a FIDE tournament, but I've played in USCF tournaments. The relevant USCF rules are similar to the FIDE rules. A tournament can prohibit using scorebooks, but in my (amateur) experience they don't; probably many tournament directors are happy to not have to provide as many scoresheets.

USCF rule 15A (similar to FIDE rule 8.1.1) states that you are to record your moves "on the scoresheet prescribed for the competition".  This is clear, but it's also only relevant if the competition prescribes a scoresheet.

USCF rule 20B (simiar to FIDE rule 11.3.1) states you are forbidden to "make use of" notes or recorded matter - it doesn't prohibit having them in a place where you can't see them. Generally a notation booklet will be open in such a way that you only have the current game visible, and not any previous games. Browsing notes on previous pages would of course be cheating, but it would also be fairly obvious to your opponent and any bystanders.  The only legitimate reason to flip a page after the game has started is if you get to move 50 or so, and by that time any opening notes would be rather useless.

While USCF rule 15G (similar to FIDE rule 8.3) does state that the scoresheets are property of the sponsoring organization, I've never had a tournament ask me to rip a page out. I get the feeling that this rule is mostly there so a player can't refuse to show it during a dispute, and it allows the arbiter/TD to insist that the opponent be able to use it to fill in his own sheet.

And finally, the USCF sells these score books on their website, calling them "A must for the 'organized' tournament player!". Presumably, they would not do so if it was ordinarily illegal to actually use them for their intended purpose.


Is it necessary to write your calculations? I have heard many times that while you're doing endgame studies,you should write your calculations,like candidate moves,variations.Is it really necessary?Can't i just check each variation one at a time in my head without having to write it down.

No.  You could do it if it helps you.
I would not waste the time writing it down when I could be using it to learn something else.


Strategies for dealing with chess burnout? I am wondering if anyone else has faced chess burnout. Do you have advice? I am a novice enthusiast (~1400) but, with a wife, child, and job, do not have the opportunity to dedicate as much time to it as I would have in my youth. Because of this I have mostly been playing correspondence chess online, which I am sure is contributing to burnout. Being tied to 50+ games at once against fairly faceless opponents is not conducive to passion for the game I am sure.

Some ideas I have had:

Play more OTB and find better live opponents. I always enjoy the game more and play better when it is personal, like a dance or a good conversation. I have found clubs intimidating but I think at this point I need to bite the bullet and go for it... at my level I am by no means good but I definitely have trouble finding challenges against casual players.

Teach (what little I know). Generally speaking, pouring into others helps motivate and inspire the teacher as well. Maybe I should start a chess club at the local library? (Just to be clear, I have no delusions of grandeur with my measly 1400 but one can always teach basics or facilitate, right?)

Have any of you successfully dealt with burnout? What were your experiences and what would your advice be?

It sounds like you simply crave some human contact in chess, and that is understandable, oh, and much more fun.

Starting a club, or getting involved in state chess "politics" is certainly one way, but it is a much bigger undertaking with more responsibility. Think hard about this commitment before you do this.

Helping kids at a school, possibly your child's school, is another. If you do attempt to teach, focus on the rules and basic tactics, which you can get straight out of a book. Give them a few puzzles each week, but go through them yourself first before you go over them with the kids. If you have any questions about certain avenues of defense for a particular problem, then you can go over it with Stockfish first so you are ready to answer their questions. You can also see if some local Master would come in and give a talk, play a few games, or give a simul. I have done this quite a few times over the years just because I like kids, and thus, did it for free.

Another think that came to my mind first, and that is go to a club, and make friends with someone, who is close in rating, and invite each other over to your homes, and play for a few hours (or all night...I did that a lot when I was first learning) every week, or couple of weeks.

I would finish the correspondence games, and get away from that. When i started playing in 1980, correspondence was still chess. Now, it is who is better with a computer program. I can see why you do not find much fun in that.

Playing tournaments is also a way to meet up with people, who you will see many times over the years.

Good luck, and let us know what you decide to do.

P.S. You could also take lessons yourself as that would also fit the bill.


Can we say for sure that Black's king has not moved? The following position appears as the 7th puzzle of Raymond Smullyan's Arabian Knights, a book about retrograde analysis.
[FEN "3qk2r/p2pp1bp/bpp2n2/8/3N3Q/1PN1P1P1/P1PPP2P/3K1n2 w - - 0 50"]

The conditions given are that "both [of White's] castles [rooks] captured on the same row, Black['s] queen's castle [rook was] captured by a pawn, and king's bishop given as odds." The stipulation is that you must find where White's rooks were captured.
I puzzled over this for quite some time, then gave up. Very early in the solution, it is stated that "Since the Black king has not moved..." However, I do not see how this can be inferred from the position. Is it necessarily true? Couldn't the Black king and queen have moved out of the way of the Black rook (which was captured on e3), and then moved back? I do not see "non-movement of the Black king" among the conditions or anything about Black being able to castle.

The conditions you gave are incomplete. The conditions include that black (to move) can castle; it's hidden in Smullyan's original problem text.

From the English book, last paragraph of the problem statement:

  Just then, however, news came that Black was about to castle. [...]

A clearer problem statement from the Retro Corner:

  Schwarz (am Zuge) darf noch rochieren. [...]

Black (to move) can still castle.


Will going to more chess tournaments and playing the Open section make me stronger and more experienced chess player? I'm currently a Class B (1600). I rarely play at chess tournaments, but this year I have been playing at a lot of tourneys. Will going to more chess tournaments help me gain experience and make me a stronger chess player, especially if I play stronger people?

No. Playing against those who can easily defeat you will not make you stronger. And it will hose the Open section, too, as you are effectively a "bye". If am referring to tournaments where there is a vigorous Open section, of course. When I played in the NY State championship, the Open section was all 2200+ and included IMs and GMs.

There are a few threads here on how players can improve. Search for them.

In a nut shell:

Work tactical exercises
Attend your local chess club and

a. play in your section

b. ask better players (+400 rating over yours, if possible) for help with analysis, and
Find an instructor to help you with specific weak points.
Once you are established at the chess club, you and an opponent can play a rated match. That is, you and your opponent can play a rated best-of-5 match or whatever. Choose an opponent who is 100 or maybe 200 points over you for a real challenge. You'll need your club's TD's approval.


UCI go with depth and movetime Is it possible to perform analysis with stockfish for a given depth, but stop in case it is taking longer than a specified time?

Something like this:

go depth 17 max movetime 10000

or

setoption name MaxMovetime value 10000
...
go depth 17

I don't think it's possible to do it in the UCI protocol. Fortunately, it's really easy to do it yourself. For example, in my SmallFish app (http://www.smallchess.com), to save the phone's battery the app would send the "stop" signal to the engine after a minute of analysis. The command is very simple:

stop

You will just need to create a timer yourself and send the stop signal to terminate the search immediately.


Is there a concept of 'good' knight and 'bad' knight? We've all heard about the concepts of 'good' bishop and 'bad' bishop.

[FEN "r1bqk1nr/ppp2ppp/2np4/2b1p3/2B1P3/5N2/PPPP1PPP/RNBQ1RK1 w kq - 0 5"]

In the position above, the white knight at f3 does not have access to either of the centre squares d4 or e5. Can this knight be considered a 'bad' knight? Is it best to have developed it to f3 or would e2 be a better square for this knight?

I'll answer this in three parts: the literal question, the concept of badly-placed pieces, and the particular example you give.

Bishops are the only piece for which the nomenclature "good" and "bad" is idiomatic. That is because the set of squares a bishop can theoretically travel to is inherent to it; a dark-squared bishop can never ever go to a light square, so if the position is such that you'd like to have a bishop on light squares, you're out of luck and your bishop is "bad". On the other hand, if you have a badly-placed knight (or queen, or rook), there's almost never something preventing you from theoretically eventually repositioning it on a good square. So people generally don't use the term "bad knights".
(People sometimes speak of endgames with a "good knight versus a bad bishop", but this is more a figure of speech meant to call attention to the fact that the bishop is bad and the knight cannot be.)
Pieces can of course be badly placed, but except in the case of a bishop of the wrong color, they are just referred to as badly-placed pieces. In fact an excellent strategical rule of thumb is to always consider improving the position of your worst-placed piece.
However, in the position you present, the knight is doing just fine on f3. It supports an eventual d4 (probably with the support of a pawn on c3), which if played at the right time could be very powerful, opening up the center. It puts pressure on Black's pawn on e5, dissuading him from playing the analogous move ...d5. And in some circumstances it could jump to g5, putting pressure on f7 or h7 (especially after Black has castled).


Karpov vs Kasparov, Game 41 In the common literature, it appears as truth that Karpov missed the winning a6! instead of Rxd1 on move 33, Game 41, in the first Karpov vs Kasparov match. But is the following position, derivate from above, really winning?
[Title "Black to move"]
[FEN "8/P3R1pk/7p/8/r4p2/1N5P/1b3PP1/6K1 b - - 3 46"]

If both sides make the best moves, it is a win for White or a draw?

White has to be precise, but I consider this position won.
The general plan Rd7 to prevent the bishop from reaching d4, bring the king to the center (net part of the plan, but this is always a good general plan and tends to restrict black's king), then find a path to get the knight to either b5 or b6.  Keeping in mind to not exchange too many pawns or to allow a perpetual, white should (IMO) easily win.


How do I know what chess books to buy? I have a lot of my own chess games in pgn format, Im wondering if there is a tool that examines my games and suggests what books I should buy to improve?

Full disclosure: I am answering my own question. I recently finished the alpha version of an app that maps chess games to diagrammed positions in chess books (https://www.thechesscite.com/).

The primary goals is to help you to make better choices about what books to buy and to help chess authors cite their colleagues. My other goal is to streamline how you study chess.

See more on the site. I’m still very early in development but have a lot of features planned. Hopefully I’ll see a little interest from the chess community and grow the tool over time. Would be happy to take feedback; however, be aware there are some minor quality of life issues I already know about, and I am a one person team. I'm eager to share this tool even if it's just getting started.


in silman's book, question about open files and global exchange In a book from J.Silman, I found this position:

 [FEN "r1qr2k1/p2bppbp/3p2p1/1p1P4/3B1P2/1B3Q1P/PPP3P1/3RR1K1 b - - 0 17"]

 1... Re8 2. c3 h5 *

It deals with the rooks, white managed to semi-open the e column and will deploy a massive attack on it. My question is : why black does not play e7-e5? After dxe6 the white pawn is sufficiently attacked by black's forces, and if there is a global exchange on e6, the weakening of the black's castle does not seem to be dangerous.

It seems to me that after e5 and exchanges on e6 and g7 the d6-pawn is hanging ...

 [FEN "r1qr2k1/p2bppbp/3p2p1/1p1P4/3B1P2/1B3Q1P/PPP3P1/3RR1K1 b - - 0 17"]

 1... Re8 2. c3 e5 3.dxe6 Bxe6 4.Bxg7 Kxg7 5.Bxe6 Rxe6 6.Rxe6 fxe6 7.Rxd6


How did classic masters like Alekhine and Anderssen practice tactics? How did classic masters like Alekhine and Anderssen practice tactics? Surely there was no chess.com or chesstempo at that time. How did the masters back then manage to increase their tactical awareness?

In Joosep Grents's wonderful biography on Paul Keres, there is a brief first-hand account of tactics training in that time period. For background, Paul was a contemporary of Alekhine and almost played him for the World Champion title, but the match never materialized.
Here's what Paul Keres had to say about training tactics in the 1930s (emphasis mine):

I used correspondence games, above all, for experimental purposes,
often opting for very risky opening lines and attempting, at all cost,
to create complicated positions which I could use to train my tactical
skills... It is easy to notice a bias toward tactics in these games,
while there are still considerable problems apparent in solving
strictly technical problems.

The article notes that at one time Paul was playing more than 100 correspondence games at once.


Cheating On Lichess? I was playing a game on Lichess the other day and all the sudden the system ended the game, awarded me the victory, and said "Cheating by White detected".    How in the world could you cheat on the Lichess site ?    Does anyone know what this means?    My  rating  is 1250 ...... who would bother to cheat against me ?

How could you cheat? This is what the Lichess terms of service say about it:

  Cheating. We define this as using any external assistance to
  strengthen your knowledge and, or, calculation ability to gain an
  unfair advantage over your opponent. Some examples would include
  computer engine assistance, opening books (except for correspondence
  games), endgame tablebases, and asking another player for help,
  although these aren’t the only things we would consider cheating.

The most common form of cheating is using an engine. I don't know the details of what Lichess does, but cheating detection can consist of comparing a player's moves to those proposed by various engines, and based on statistical analysis one can come up with criteria for when the player's moves were "suspiciously similar" to an engine's.

Lichess also allows people to register bot accounts, but those must be clearly labelled as bots. So I suppose that another form of cheating could be to create a bot account and pretend that it is a human.

I also found this old FAQ:

  How are cheaters identified?

  A:

  Using the suspicious games themselves. The degree to which computer players differ in playing style and strength, to most human opponents
  that rely on them, is in most cases enough to reverse-engineer
  information from the game beyond what moves were made.
  Using the player's other games. A player's profile shows all their games, including games where it is apparent that there was no
  cheating. Games where a player cheated and games where a player did
  not cheat have very different results when reviewing them using a
  chess engine (or Lichess' computer analysis feature).
  Using the player's history. On every player's profile are public graphs of rating and average history, game database exports upon
  request, and win to loss ratio.
  Time statistics. Anyone can see the public time consummation information for games, i.e., the time-per-moves.
  A statistical analysis of the suspected user's playing behaviour. This statistical analysis is only visible to the lichess team.
  Copying and pasting the suspicious game(s) into an engine and seeing how similar the moves are.


Playing Styles of Fischer and Botvinnik They say Botvinnik had 'scientific' approach to chess and Fischer's style was crystal-clear.

What does it mean?

Could you please enunciate about the styles of these masters in a more lucid way?

Botvinnik believed in peer review.  He would write up annotations for his games, and publish them hoping for feedback from other players.  He also recommended to his students that they annotate their losses, and also look for mistakes in the games they won.  These elements are all part of his 'scientific' approach.

Fischer always kept the endgame in mind, preferred bishops over knights, grabbed pawns if he thought he could get away with it.  Mikhail Tal would wait until the time control drew near, and then suddenly start to complicate the position, trying to induce his opponent into blundering.  Fischer was much more straightforward, playing the board more than the man, not indulging in psychological ploys as much (at the board anyway).  After the game was over, his opponent would look at Fischer's moves, and think they looked obvious in retrospect.  These are the factors that make his style 'crystal clear.'


Why are these moves recommended? I am playing chess on the chess.com app with the top three suggested moves:

I am an amateur. I get the basic idea that developing your knights is a common, good thing early in the game, but why is that specific pawn move a7-a6 recommended? The queen could take it, but it’s protected by the rook.

The point is that 4...Nc6 could be met with 5.Bb5, when the knight is pinned and it's likely White will exchange it off with Bxc6. Without the c6-knight, Black will lose some influence over the key d4- and e5-squares. Playing ...a6 before developing the knight aims to prevent this.

Of course there's a trade-off here, since Black is spending a tempo just to prevent a relatively innocuous exchange.


What is the strongest chess engine working on Arduino (Atmega328)? What is the strongest chess engine working on Arduino? Or does any engine work on it?

Not every chess engine works on Arduino as it doesn't run a conventional *nix operating system.

There's a list of chess engines that do work here:

http://chessprogramming.wikispaces.com/Arduino

Updated url from Fabian's comment:

https://www.chessprogramming.org/Arduino#Chess_Programs


What's next after first 5 months and 700 points? I started playing chess in July. I was at a 600 rating on Chess.com for a month. I started playing seriously in August and have played regularly (at least a few blitz and rapid games everyday). Currently, I am rated 1300 on Chess.com after 800 games(10 minutes). I seem to have moved past my blundering days (although still blunder every now and then). I also play shorter games on lichess (rated 1400 on blitz).

I haven't really read any literature yet. I started reading Logical chess by Chernev. I play the games out on the board and they are fascinating but I don't see how I can improve with them. Also, I do puzzles on lichess frequently. I haven't seen any significant changes in my thinking process recently when I play games. What's the next thing I should do?

My goal really is to be able to create and execute longer plans in the game while being able to read the opponents plan and defend. I was told this corresponds to the ~1900 rating range, so that would be my target (rating wise) by the end of 2019.

This is an open-end question. My recommendation is join serious face-to-face tournaments where you play games at the classical time control. Playing blitz is fun, but not a good idea for learning chess.


Creating a New Neural Network for chess I'd like to have my own chess engine similar to Leela for personal use. I’d want it to have a decent strength, let’s say 2k, and be able to play with it.

I'm wondering if I can use Leela to create a new network that is trained on select number of games (essentially supervised learning instead of self play). Basically, it will be a network that can train on games of past masters such as Tal, Morphy etc. Any help is appreciated.

I have done some Deep Reinforcement Learning so I can tell you that making a NN is not the way forward here and it is far from easy. If you manage to take the NN of LC0 as it is and train it with another algorithm (according to how you want it), you can get your training software. Even designing this algorithm would be difficult.

The point here is that LC0 NN is capable of having a strength matching 3900 levels. It learns patterns in chess very efficiently. If you want a strength of 1600 or 2000 or whatever your rating is, it's definitely more than capable. Maybe you would need a new NN if you want a strength of 4500. Intelligence is already out there. You just have to customize it for your needs.

A much more practical thing would be to try to beat LC0 snapshots of past close to your rating. They should be available on lc0 site, you'll have to make the appropriate frontend. But you can get an easier version by trying to beat stockfish levels on lichess. Maybe you can request the lichess community to add more levels at smaller intervals or make some more yourself.

Earlier engines like Fritz and I guess the very old Deep Blue itself were trained on GM games so this is not anything new. Self play is much stronger and you'll be able to feel playing many levels how NN itself learns patterns step by step.

P.S. Such a thing would help Carlsen, Anand and others much more as you can learn through books but they can't. They can try to beat 2900 LC0 but you can learn from books. Everytime they crush the opponents who write the books we read.


Is there a description of the files used by USCF ratings reports? When a USCF rated tournament is submitted for rating, the tournament director submits to the USCF a set of dBase III files (.DBF files) that include the tournament data.  I've never seen a description of the structure of those files anywhere - I mean, I know they're dBase files, but as far as the fields and such.  Does such a description exist?

A long while back, I was talking to someone at the USCF who worked on the website and online tournament submission, who told me that there was in the planning stages an XML-based format for submitting tournament results, and that it was in limited testing at that time.  I've never seen nor heard anything else about this since then.  Is anything like this still in progress?  Is there a description of that format anywhere?

Google turned up many ways to read or convert DBF files as well as detailed descriptions of the contents.

See the gory details here
https://en.wikipedia.org/wiki/.dbf#File_architecture_overview

and yet more gory here:
http://www.dbase.com/Knowledgebase/INT/db7_file_fmt.htm

with more details still at this site
http://web.archive.org/web/20150323061445/http://ulisse.elettra.trieste.it/services/doc/dbase/DBFstruct.htm

yet another view of the DBF file
https://www.dbf2002.com/dbf-file-format.html


Another good chess problem [Title "The Chess Monthly, 11/1860, Helpmate In 3 Moves (Version)"]
[FEN "6R1/7q/8/5k2/3K1B2/8/8/8 b - - 0 1"]
[startflipped ""]

Now, in this chess problem by Samuel Loyd, both sides work together for a checkmate.  If Black is to move first, how can White give mate in 3 with Black's cooperation?

Nice one:

 1 Kf6 Ra8! 2 Kg7 Bb8 3 Kh8 Be5#!  ("Indian theme")


How did the Grand Prix Attack get its name? The moves 1. e4 c5 2. Nc3 Nc6 3. f4 characterize the Grand Prix Attack in the Sicilian defense.

     [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

     1. e4 c5 2. Nc3 Nc6 3. f4

How did the Grand Prix Attack get its name?

From this page, I quote

  The Grand Prix Attack got its name from the many strong British
  players who used it on the Grand Prix Circuit in the 1980's

As Remco Gerlich said, It was used by British players on the British Grand Prix circuit. Weekend tournaments that also have a combined standings.


Promotion transition What is the point at which promotion occurs?  Does the pawn as it enters the 8th rank become a promoted piece as it enters or does it have to occupy as a pawn then be promoted?  If promotion occurs as it enters then a pawn would not be blocked from moving to the 8th rank if some piece was in its way.

When a pawn reaches the 8th rank, it then must be promoted to a Queen, Rook, Bishop or Knight.
The pawn can capture normally to reach the 8th rank. IE fxg8=Q, but as we know the pawns don't attack pieces whom are directly blocking them so captures straight is not an option.

According the the FIDE 2017 handbook promotions can be done in numerous ways:
4.6.1 the pawn does not have to be placed on the square of arrival,
4.6.2 removing the pawn and putting the new piece on the square of promotion may occur in any order.
4.6.3 If an opponent’s piece stands on the square of promotion, it must be captured.
It is worth noting that incorrectly promoting in Blitz or Rapid games results in a loss by illegal move according to the official rules.


What is the maximum Elo rating that Magnus Carlsen could have if he loses the 2014 WCC to Anand? What is the maximum Elo rating that Magnus Carlsen could have if he loses the World Chess Championship 2014 to Anand? Would this result from a 6.5-5.5 result or would the relative rating change mean that if he lost more quickly that would be better? Also, are the players playing 12 rounds regardless of the current score?

In a hypothetical situation where Carlsen knew that he was going to lose the match and his number one priority was to preserve his rating points, then his best option would be to lose as quickly as possible. As pointed out in this question (EDIT: Values updated as per JiK's comment below), Carlsen will lose 1 rating points for each game he draws with Anand. The only way that he could extend the match and not lose points in the process would be to win as many games as possible before losing.

Assuming Anand wins with the minimum possible score of 6.5/12, Carlsen will lose a minimum of 17 points (11 draws x 1, 1 loss x 6). This does not change if draws are replaced by a win for either side.

However, if Anand was going to win with a draw and 6 wins, then Carlsen stands to lose
 37 points. If Carlsen somehow knew this would be how Anand would win, then he could attempt to interpose as many of his own wins (up to 5) as possible, ameliorating the loss somewhat. Even in this situation, Carlsen's best result remains a net loss of 17 points.

EDIT: And to answer the question as it is worded in the title: Carlsen's rating (assuming no results outside the WCC match are counted) would be no more than 2863.0 - 17 = 2846.0


Would a classic full time armageddon tiebreaker be balanced? I think that classic chess and rapid chess are two quite different kinds of sport. The classic chess title was undecided this year 2018.

Why not use the armageddon rule, that black wins if tied in exchange for a white time advantage, in a classic format? Say for example normal classic time rules for white, but in total only 100 minutes with no increment per move and no additional time after move 40 for black. Could something like that be fair or is it too easy for black to force a drawing position during the first 40 moves? Is armageddon all about blunders under time pressure?

That wouldn't make any sense. In a long game between two 2800+ players, a draw is always very likely. Carlsen and Caruana understand exactly how to steer a game to a draw.

Whoever gets Black would have a winning advantage before the game even started.


How can I "see the board"? I often get into stupid blunders, get myself into pins and threats that I don't see on time etc.
How can I avoid that ?

Learn chess geometries and patterns. For example,
if two of your pieces stand on squares of opposite colors (or along a diagonal with one square between), then the pieces cannot be forked by a knight; and if the pieces will remain there for several turns, then they will remain mostly immune to that threat.
Learn more chess geometries and patterns. For example, a bishop is often an eventual threat to attack any foe that stands on its diagonal, even if, say, two pawns standing on the diagonal currently block the attack. If the bishop remains on the diagonal for several turns, then a player can see the potential, eventual threat, all along the diagonal.
Learn further chess geometries and patterns. For example, if your opponent has only one bishop, if you have chosen a square of the opposite color on which to place your rook, then the problem that the bishop might eventually capture the rook is less worrisome.
Observe that items 1, 2 and 3 are all positional in nature. An opponent of intermediate ability—say, ELO 1500—may see less of the board than you think; but if he or she has positioned his or her men on squares on which it is hard for you to develop threats against them, it can seem as though the player sees the board in a way you do not.
Know where your hanging (unguarded) pieces are—knights, bishops, rooks and queen. Pay special attention. Whenever you have an unguarded piece, the opponent might develop a tactic against it. That's okay. No chess player can guard all pieces at all times, but if you cannot hold the entire position in mind at once (I cannot, either), then you can at least hold certain features of it in mind. Hanging pieces are often an important feature.
Avoid wasting tempos. When you make a pointless move, this usually affords your opponent valuable time to exploit weaknesses in your position. When all your moves are purposeful, by contrast, your position might still suffer weaknesses—even weaknesses of which you are unaware—but your purposeful moves may deny the opponent the opportunity to exploit the weaknesses insofar as that your moves have forced the opponent to defend rather than attack.

Much of my answer is indirect, but you can see the board better when you have arranged the board such that there are fewer things on the board that are necessary for you to see. This is what positional play is about.


Compiling Stockfish to disable own castling while allowing opponent castling For artistic purposes, I would like to create and study engine games in which only one side is able to castle.
For this, I need to compile a version of Stockfish which never castles, and doesn't consider its own castling in its calculations, whereas calculates with castling for the opponent.
I have gone through the types.h file and found the following:
enum MoveType {
  NORMAL,
  PROMOTION = 1 << 14,
  ENPASSANT = 2 << 14,
  CASTLING  = 3 << 14
};

enum CastlingRights {
  NO_CASTLING,
  WHITE_OO,
  WHITE_OOO = WHITE_OO << 1,
  BLACK_OO  = WHITE_OO << 2,
  BLACK_OOO = WHITE_OO << 3,

  KING_SIDE      = WHITE_OO  | BLACK_OO,
  QUEEN_SIDE     = WHITE_OOO | BLACK_OOO,
  WHITE_CASTLING = WHITE_OO  | WHITE_OOO,
  BLACK_CASTLING = BLACK_OO  | BLACK_OOO,
  ANY_CASTLING   = WHITE_CASTLING | BLACK_CASTLING,

  CASTLING_RIGHT_NB = 16
};

What can I do to disable castling in moves and calculations of Stockfish?

There is no need to compile your own version of Stockfish for this.  Instead you can just start from a position that omits castling rights for one side or the other. The FEN for the initial position without castling rights for White is
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w kq - 0 1
and the FEN for the initial position without castling rights for Black is
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1
The FEN can be entered into Stockfish using the UCI command
position fen FEN
where FEN should be replaced by the FEN in question.


Mouse vs Touch performance for bullet chess Though I have played chess for a long time, only picked up bullet chess very recently. And with better results than expected. However, as I play at random times I find myself playing in different settings:

With a mouse
With an Ipad (touchscreen)
With a smartphone (touchscreen)

What surprised me is that the mouse does not significantly outperform the alternatives.
Though I am struggling to analyze this numerically, I feel that the mouse is by far best when making planned moves (especially something like a4-a5-a6-a7 or Ra1-Ra2-Ra1-Ra2...) where the smartphone is faster for making unexpected/semi expected moves (typically allowing me to build up pressure in the midgame where I kind-of know what kind of moves to make but cannot commit to an exact order in advance).
Now my question:
Are there any evaluations on touch vs mouse speed/accuracy for 'normal people' done beyond the scale of an individual? Especially for different kind of moves?
This is more a question of curiosity, but perhaps there could be practical applications. For instance, if the results are conclusive I might get some of the top players to test using a touchscreen instead, or if the switching is not to bad this could even be done for just the midgame.

What have I tried:

As mentioned I tried it myself
I searched online, found plenty of individuals who say one option or the other is better. Also found several statements specifically about the mouse being faster in a pre-move setting.
I checked what (top) players do in chess and other games. Most of them use a mouse, however this may simply be because they cannot afford to be slower at expected moves/pre-moves.

I am still thinking on how to investigate this myself. Of course chess based analysis would be the best, but perhaps it is sufficient to tap into more general research on device control.

Your question is interesting. I think I can share my experience because I am playing bullet for quite some time now. I used to use a touchscreen (Galaxy Tab S5E), but for the last couple of months, I am using a mouse.
Both of them have benefits as well as drawbacks to their side. The best benefit for the touchscreen is reachability with accuracy. You can touch wherever you wish to and that too with accurate (assuming you are using 5.0+ inch touchscreen). On the other hand, the mouse is fast, but not accurate and may also "slip" in the crucial move (often known as mouse-slip).
So, the question is why is the mouse still the favourite option to major chess players?
The answer is "Polling Rate". An average wired gaming mouse offers a polling rate of 1000 Hz, compared to 120Hz touch refresh rate from the touchscreens. And this plays the crucial role in bullet because of each millisecond counts in it. So, I think, it's important to choose almost 10x faster equipment, though it's not that accurate.
Last but not least, Hardware. I ran lichess lag test on Google Chrome in my PC  [Windows] as well as in the official android app [Pixel 3A XL]. Both of them were connected to the same wifi network. Though the lichess-server latency was the same in both devices [0.1 milisecond], "Network between Lichess and you" (i.e ping) varies significantly from mobile (181ms) to PC (103ms). So, clearly, mouse in a PC is more superior choice than the touchscreen, at least for me.
Thank you.


Connecting Chess Engine with a Java program I wanted to make a 1 player chess game.

The idea is:

The move made by the player would be displayed on the GUI.
It is sent to the Chess Engine in its own specific understood form.
Then the result of the Chess engine would be taken and then made visible on the GUI.

Currently I have made no progress on it and am on a dead end. My current program on Java lets 2 players play with each other. The program manages the rules that have to be followed and which moves are illegal. But for a single player game I wanted an AI for my game that can take inputs and give outputs. I searched online for various open source chess engines like Stockfish. But found nothing about using it in my program.

I tried to work on to create my own engine but it was quite a challenge for me. Hence connecting it with an external AI is the only solution I think there is.

Let's break it down:

You have a working Java chess board that you can use to move pieces
You want a chess engine (engine is a more precise term than AI)
You want to download Stockfish and use it
You want to invent a new protocol or technology to communicate your chess board with the Stockfish engine

To me, your question is really:

How to connect an external chess engine such as Stockfish within my own chess GUI in Java?

Useful old posts in this site:

Chess Engine API
What is the optimal way to use Stockfish programmatically?

Basically, what you need to do is:

You shouldn't invent your own technology, you should study the UCI protocol. http://wbec-ridderkerk.nl/html/UCIProtocol.html is a useful reference. I can get you started, do this:

Download Stockfish
Open Stockfish in a console/terminal, don't double-click on it with your mouse
Type ucinewgame and then go movetime 1000. Do you see Stockfish's move?
Read the protocol specification and learn how to analyze a position, and the output format.

Write a UCI output parser. Parse whatever information you want.
Use the information to make a move on your chess board.

The only technical difficulty I can see here is to establish a "connection" between your GUI with the engine. This is done by creating a new process, running the engine.

  https://stackoverflow.com/questions/2006035/how-to-create-a-process-in-java has information on how to do it.

Once you have the new process, you can establish a simple standard input/output pipeline. https://stackoverflow.com/questions/27081918/java-how-to-send-a-value-to-child-process-using-outputstream has the details. Ask on Stackoverflow if you're not sure.


recommend a book on mid-game plan and board evaluation Could someone recommend a book on mid-game strategy please?

Things I am especially interested in are

Make plans (and foresee opponents plan and stop it)
Evaluate current position
Evaluate positions at the end of calculation

I guess 2 is somewhat blended in 1 and 3. My problem is that even though I may be able to do some evaluation for the current position, it's very hard to do the same at the end of each variation I calculated. So I'm looking for both a more involved way to analyse current position and also a quick way to roughly evaluate positions down the line. (Or maybe practice is the only way?)

Thanks.

(Not really interested in tactics as this is not my bottleneck)

"The Art of The Middle Game" by Keres and Kotov comes to mind.  And an older book,"Strategy and Tactics in Chess" by Max Euwe, was long considered a classic in this area. Of course study always has to be combined with practice.


How to handle resignations from unlost positions when learning? I played a game against bemeurer, a friend of mine who's learning chess. He's only got me to play against but he's learning quite quick.

Of the 8 games we played so far, I won all of them. Most quite easy, but this last one was a tough fight. We play on Chess.com, which has a chatbox.

[fen ""]
[Site "Chess.com"]
[Date "2016.03.25"]
[White "bemeurer"]
[Black "Pimgd"]
[Result "0-1"]
[WhiteElo "741"]
[BlackElo "1259"]
[TimeControl "1 in 3 days"]
[Termination "Pimgd wint door opgave"]

1. Nc3 e5 2. a3 Nc6 3. e4 Nf6 4. Nf3 d6 5. Bb5 a6 6. Bxc6+ bxc6 7. d3 d5 8. Bg5 dxe4 9.dxe4 Qxd1+ 10.Kxd1 Ng4 11.Rf1 h6 12.Bh4 g5 13.Bg3 Be6 14.h3 Nf6 15.Nxe5 c5 16.h4 gxh4 17.Bxh4 Be7 18.b4 cxb4 19.axb4 Nd7 20.Bg3 Bxb4 21.Ne2 Rg8 22.c3 Bd6 23.Rg1 f6 24.Nxd7 Bxd7 25.Bxd6 cxd6 26.Nd4 h5 27.Ke1 h4 28.Kf1 h3 29.gxh3 Bxh3+ 0-1

Upon making 29. ... Bxh3+, I said "haha, now I get a free rook". My opponent expected that it would have been a rook trade, like 29. ... Rxg1 30. Kxg1.
With 29. ... Bxh3+, I expected that he'd be forced to play 30. Ke1, leaving me to play 30. ... Rxg1+, 31. Ksomewhere, Rxa1. Seems like I actually get 2 rooks. After that exchange, the game is obviously lost for White.

So upon 29. ... Bxh3+ and my exclamation, he resigned. Whenever a game ends, we talk about it in a chatroom here on stackexchange, so that I may explain to him how he played and why I am doing what I am doing. To me, it seems he's growing quite well, but I'd like to be able to hand him a fair victory one day.

During the analysis, it seemed that we had actually missed 30. Ke2, and as a result, my opponent resigned even although the reason for resignation was not true.

In a competition, I'd happily take the win, but here, it's not useful for me to take wins - right now I am the better player, and me winning doesn't change that. I've been wanting to play a fair endgame against him to train his skills in that area, but this resignation throws that idea out of the window.

With the game resigned, however, I went and tried to take an analytical look at the game.

[fen ""]
[Site "Chess.com"]
[Date "2016.03.25"]
[White "bemeurer"]
[Black "Pimgd"]
[Result "1/2-1/2"]
[WhiteElo "741"]
[BlackElo "1259"]
[TimeControl "1 in 3 days"]
[Termination "Pimgd wint door opgave"]

1. Nc3 e5 2. a3 Nc6 3. e4 Nf6 4. Nf3 d6 5. Bb5 a6 6. Bxc6+ bxc6 7. d3 d5 8. Bg5 dxe4 9.dxe4 Qxd1+ 10.Kxd1 Ng4 11.Rf1 h6 12.Bh4 g5 13.Bg3 Be6 14.h3 Nf6 15.Nxe5 c5 16.h4 gxh4 17.Bxh4 Be7 18.b4 cxb4 19.axb4 Nd7 20.Bg3 Bxb4 21.Ne2 Rg8 22.c3 Bd6 23.Rg1 f6 24.Nxd7 Bxd7 25.Bxd6 cxd6 26.Nd4 h5 27.Ke1 h4 28.Kf1 h3 29.gxh3 Bxh3+ 30. Ke2 Rxg1 31. Rxg1 Rc8 32. Kd2 Rc5 33. Rb1 Bc8 34. f4 Ra5 35. Rb6 Kd7 36. Rb1 Kc7 37. Rg1 f5 38. Rg7+ Kb6 39. exf5 Bxf5 40. Re7 Bg4 41. Rf7 Bh3 42. Rg7 Bf5 43. Re7 Bg4 44. Rf7 Bh3 45. Rg7 Bf5 46. Re7 Bg4 47. Rf7 1/2-1/2

It gets stuck on positional repetition with an online chess engine called "GamboChess JS 6.0". Given that the positional repetition is made by white I guess black is playing the stronger position, although it does seem like White is in control, black is just responding to that and white can't break through so they just decided to repeat forever.

Now that I have run a chess engine on the game, though, I can't really go back and offer to play from the last position. I already know my moves based on the chess engine's suggestions, and either my opponent will play the chess engine moves leading to a boring draw, they will slip up letting me win, or the chess engine isn't seeing all the moves it should and the analysis is useless.

I have three main questions:

How to handle situations like this, where the person you're teaching resigns, and you think it was okay, but afterwards in analysis it turns out it had gone either way?
Was the position after move 29 actually lost for White?
How to convert a position into a score using chess engines, so that there's a measure we could quickly use to decide who had the advantage?

I can split the questions up into several questions if needed (if that's the case, then please answer just question 1).

1) Unwarranted resignations happen on occasion even in tournament play, sometimes even in a won position.  If your student does this in an instructional game, it's a teachable moment.  In the present game, you might learn too: saying
"haha, now I get a free rook" during the game is distracting the opponent,
which is against the rules whether or not you in fact do win a free rook;
if you hadn't said that then your student might well have found 30 Ke2 and defended the resulting endgame, rather than resigning out of an abundance of
trust in the teacher.

2) Looks like an inferior endgame for White: material is equal, but Black has a distant passed pawn already supported by the Ra8, and also the Knight, though centralized, may have trouble against the Bishop and the a-pawn.  31...Kf7 seems like a better try than 31...Rc8, but I can't judge whether it's actually winning.


What are good openings to study to get more experienced players out of their comfort zone? Sometimes I end up getting the opportunity to play a friendly game with someone who has played a lot more chess than I have; these games seem more fun and interesting for everyone (and I seem to end up with a better chance of winning) when I can push play away from common positions without incurring a big early disadvantage. Are there openings that I can study to accomplish that more dependably?

You can play a surprising opening, which your more experienced opponent has probably encountered very rarely, like a gambit or a rare sideline. Theoretically-wise you will stand on more even ground then. Even better, since you will play this line often, you will have more practice with it than him, improving the odds even more. But usually such openings are seldom played for a reason, at example because they are unsound, or you have to remember very complicated lines, or they offer less winning chances than competing opening systems. There are so many such opening systems (there are even periodicals dealing exclusively with them) I don't list any of them over others.

Apart from this general thought I would suggest a more detailed approach. Try to understand what the exact nature of the advantages of your opponent (or what your own disadvantages) are and act accordingly:

Tactically much better than you?  => go for quiet lines with focus on strategic plans,
use closed systems with few tactics so you deny him the use of his
advantage
Much better theoretical opening knowledge? => use sidelines
and shaky gambits, and pray he doesn't know those ugly refutations
and critical lines
Strategically much better? => choose simple
systems and learn the ideas behind them thoroughly. You will close the
gap soon and know the resulting structures as good as he.
Generally better in every aspect? => play what you like
most and learn from your defeats

A word of warning, though. For a competing mind this might sound like a clever plan. True, it is fun to spring a surprise weapon at a stronger opponent and gain a victory this way. But, and this is a big BUT, in the long run your goal is probably to become a better player over time, and this means gaining a deeper understanding of all the chess topics. Remember you can't get better at tactics by avoiding them ;) When your opponent leaves his comfort zone, he may play weaker. But leaving your own comfort zone makes you stronger - in the long run!


What is the algebraic notation for the bishop? Let's say that I have a pawn at b2 and a bishop at d2 and I want to capture the pawn on c3 with my bishop. The expression I used is bc3. However, it uses my pawn at b2 to capture the pawn at c3. I then tried b2c3, but it did the same.
How do you use bishop to capture the pawn at c3 with algebraic expression in this case?
[FEN "rnbqkbnr/pppp1ppp/8/8/8/2p5/PP1BPPPP/RN1QKBNR w KQkq - 0 4"]

1.Bxc3 (1.bxc3)

The expression I used is bc3

Lowercase letters ALWAYS refer to pawns/files. Uppercase ALWAYS refers to pieces. You need to use Bxc3 for "Bishop at d2"xc3.


Algebraic notation avoiding ambiguity rank or file preference In the following example (and similar situations you can make up), both queens can capture the knight. If for instance the queen on f5 takes the knight, this could be written as: Qfxd3 or as Q5xd3. Is there a preference/guideline/law/... for using one or the other notation in this case? I am specifically interested in notations made by humans in a normal game situation, not in PGN notation.

8/8/8/5Q2/8/3n4/4Q3/8 w - - 1 1

This would be Qfxd3.

From wikipedia (emphasis is mine):

  When two (or more) identical pieces can move to the same square, the moving piece is uniquely identified by specifying the piece's letter, followed by (in descending order of preference):

  the file of departure (if they differ); or
  the rank of departure (if the files are the same but the ranks    differ); or
  both the file and rank (if neither alone is sufficient to identify    the piece—which occurs only in rare cases where one or more pawns
  have promoted, resulting in a player having three or more identical
  pieces able to reach the same square).


What is the point of time increments? I am having difficulty understanding the purpose of increments in time control. What is the point? If it just adds more time to the game, why not simply make the game that much longer? I am aware that I am missing something fundamental here. Apologies for this complete newbie question!

It depends on what you mean by "increments". If you are referring to something like "playing a game in 10m + 4s", then the main reason is preventing that a player with a huge material advantage (v.g. king plus rook versus king) doesn't lose on time. With the increment of 4 seconds after each move is made, the player with the advantage will have no problem winning the position. Without increment, if the advantageous player has something like 1 or 2 seconds on their clock (and provided the other player has plenty of time, or just much more than a couple seconds) they'd probably lose on time -which usually is called "getting (dirty) flagged" in games without increment.
This is a somehow famous example of an online game in which Gata Kamsky was (dirty) flagged in a 3 minutes game without increment, with just one rook and king per side.


How Do Top Engines' Achieve Large Search Depth Im new to programming chess engines. I have implemented a transposition table, search tree, and alpha-beta pruning, an can analyze ~80000 boards per second. However, even with alpha-beta search, when I increase the depth of the search by 1, it analyzes approximately 20 times as many boards and takes 20 times as long. Therefore I can only search 5 to 6 moves deep, which is clearly terrible. How is it that top engines can analyze 20+ plays deep? Even if I could analyze 100x as many boards each second, that would still only get me 1.5 more plays deep, so I don't think my board analysis speed is that big a factor.
Also, are there any books that you would suggest for a good introduction to chess programming?
Thanks in advance.

I am not a specialist about programming chess engines, but the notions of depth is a little bit misinterpreted. "Depth" is somehow the maximal value reached by the engine during his search but the engine is absolutely not searching in every position with a depth of 20 moves. Modern engine uses heuristics to determine line of play and reducing the number of positions to analyse.

I don't precise way to do so but I can imagine that line of play with too much imbalance are not completely analysed by the engine, for example.

One point as well is about the evaluation function of your algorithm, if the function is too time-consuming then the algorithm would run longer as well.

One thing is about the transposition table (TT), you need to check if the TT is not becoming too large which would result into some memory issues.

I really believe that the number of positions to analyse at each step is strongly bound by the way of choosing which position to analyse or not.

I think you know the chessprogramming wiki, but there is a lot about improving searching on http://chessprogramming.wikispaces.com/Search.

I hope I've helped you :)


Losing against lower rated opponents I play many blitz games on Lichess per day, 5 + 5 and up. When I play my A game, I can beat any 2000+ player with ease, like today. Sometimes 2200, but I don't play them much.

Anyway sometimes like what happened last week, I lost many back to back matches against various 1500, 1400 and even 1200! My rating dropped just like that to 1600, perhaps less, now I'm at 1850 looking to be back at 1900 maybe 2000 soon as I'm on a winning streak.

That's the only reason I'm not 2200 player, coz one day I might win against 2200, next day I might lose against 1200. I'm mostly play queens gambit or sicillian, no crazy oppenings.

Does that happen to all of you or is it just me? I play too many games per day, is that why this is happening to me?

I noticied that if I play one game or two, every few days I can win more high rated player with ease. I noticed that if I play many games per day I start feeling numb and anxious and stop seeing the board. is it just me or did anyone played totally rubbish after many games?

I think I have chess addiction, if there's such thing, where I continue to play until I start losing and then play and lose more and it's so annoying.

Chess can honestly be a very tiring game since it takes a considerable amount of brain power to play. You simply play worse when you play a lot of games in a row compared to several over the course of a few days because you're just tired, it happens to everyone to a certain degree. The last thing you mentioned is called going on tilt, its a common occurrence in gaming where a lose can be demoralizing and cause you to play worse which may cause you to lose again and continue the cycle. The best way to deal with tilt is just take a break. Also if I understand you correctly you were talking about blitz chess, in my opinion blitz chess is more inconsistent compared to normal timed chess as in the time factor will give you a greater chance to beat a higher rated player compared to if you were playing normal time control chess but also a higher chance for you to lose against a lower rated opponent. I think fatigue and all those other factors I mentioned could play a part of you losing to "weaker" opponents.


How do you keep chess fun when your opponent constantly beats you? How do you keep chess fun when the only person that wants to play against you beats you all the time? I am struggling to want to keep playing, because I get smashed all the time, and it is not fun anymore.

There are many people who want to play chess with you. You can play chess online! Online sites such as chess.com and lichess.org will match you with opponents of similar rating so you should win about 50 percent of the time. Furthermore, playing online as well as studying chess will immensely improve your chess, and maybe you'll play your friend again and this time you will win!


When should you trade to prevent castling? The main question I have is about a game I played. What do I need to know about how to take a piece so that my opponent's king can no longer castle?

In the following game, I played Bxd2+ to do so. The Stockfish lines seem nonhuman.

[FEN "r1b2rk1/1p3ppp/2pp4/p1q1p1bN/P1P1P3/1PP3Q1/3N1PPP/R3K2R b - - 0 1"]

1... Bxd2+ {I played this to keep the king in the center.} (1... Bh6 2. Nf6+ Kh8 3. Qh4 d5 4. g4 Qe7 5. g5 gxf6 6. gxh6 Rg8 7. cxd5 cxd5 8. exd5 {Why would black want this?}) (1... f6 2. Nxg7 Kh8 3. Nh5 Rg8 4. Qd3 Bxd2+ 5. Qxd2 {Why would black give up the g7 pawn and then take the knight allowing the queen to capture back instead of what I played forcing the king to move?})

The problem with that move is a number of things.

You gave up the bishop pair.
His attack on your king is stronger than yours on his king, and you traded off a defender.
You have no time to go after his king since yours is threatened with mate on the move.
Already with three minors traded, his threats aside, there might not be enough firepower to attack his king with impunity.

Keeping a king in the center is only part of the idea behind keeping a king in the center. You need to be able to open more lines to attack it, and that also requires having other pieces that are already somewhat trained on the opposing king already. Once the king is stuck, you either need to be able to open lines immediately with pawn play, or an additional sacrifice. If you cannot do that, you should question the trade, and ask if you are simply trading your good piece, in this case a B with some good scope, for a worse piece, in this case a barely-developed Nd2.

In your line with 1...Bh6, your line is best play for white per the computer, and in that line, white is barely holding it together. At the end, there is 8...Rg4 9.Qh5 Bd7, and that is advantageous for black, so that is why he would want that. Black's K is quite safe on h8 there, but where does white go with his? The Qh5 is also not comfortable, and in some lines Rf4 and Bg4 are threats. White is walking a very fine line there. From there, if black can find a way to open the position just a little, the white king will come under a strong attack.

 [FEN "r1b2rk1/1p3ppp/2pp4/p1q1p1bN/P1P1P3/1PP3Q1/3N1PPP/R3K2R b - - 0 1"]

1... Bh6 2. Nf6+ Kh8 3. Qh4 d5 4. g4 Qe7 5. g5 gxf6 6. gxh6 Rg8 7. cxd5 cxd5 8. exd5 Rg4 9. Qh5 Bd7 {White is walking a very fine line here. From here, if black can find a way to open the position just a little, the white king will come under a strong attack.}