Books for chess traps I have seen (and studied) some books on opening theory. They basically deal with chess openings and various lines in which those openings can transform into. But I haven't found a book which completely focuses on opening chess traps. I want to learn chess traps which originate from various openings. I have looked online and found traps like "Legal trap", "Fishing pole trap", etc. Can someone recommend me a book or even some other online material(s) which basically have a compilation of such kind of traps?

Chess.com has a review of 700 Opening Traps by Bill Wall:

  Bill Wall is a well known chess writer and his book '700 opening traps' is available as a free download from the website mentioned above, as well as his many other books and articles.

The book is available for download at http://billwall.phpwebhosting.com/ (this opens the book as a PDF).


How to fix 1 turn tactical errors I am a very good attacking and tactical player. There is just one problem. While I catch combinations that might even require 5 or 6 moves, I cannot find 1 turn ones. Let's see this game I played today:

 [FEN ""]

 1. e4 e5 2. Nf3 d6 3. d4 exd4 4. Nxd4 Nf6 5. Nc3 Nbd7 6. Bc4 Ne5 7. Bb3 Be7 8.
Bf4 O-O 9. Qd2 Ng6 10. Bg5 Re8 11. O-O-O c6 12. h4 d5 13. exd5 Nxd5 14. Bxe7
Ndxe7 15. h5 Ne5 16. h6 g6 17. Qf4 Nd5 18. Nxd5 cxd5 19. Nf3 Nxf3 20. Qxf3 Qg5+
21. Kb1 Bg4 22. Qc3 Qe5 23. Qxe5 Rxe5 24. Rxd5 Re2 25. Rhd1 Ree8 26. R1d4 Re1+
27. Rd1 Rxd1+ 28. Rxd1 Bxd1 29. f3 Be2 30. c4 b5 31. cxb5 Bxb5 32. Bd5 Rc8 33.
Be4 f5 34. Bc2 Kf7 35. a4 Rxc2 36. Kxc2 Bxa4+ 37. b3 Bb5 38. g4 f4 39. Kc3 Kf6
40. Kd4 Kg5 41. Ke4 Bc6+ *

I was white. This is the one I am presenting, but there are many games where I missed 1 turn tactics. Please help me.

It is a common problem to calculate all the variations and then suddenly realize that the first move was simply terrible. Actually, there is a rule that should be applied after finishing a complicated calculation, the Blumenfeld rule!

The Blumenfeld rule is formulated roughly as follows. After finishing a complicated calculation, take a fresh look at the position on the board. Try to picture the position directly after the next move you plan to make. Check whether you are missing something trivial. Are you perhaps losing a piece after this move? Are you missing a simple check that makes you lose material? Perhaps you will even be checkmated in a few moves? Only after completing this check for terrible blunders can you now go on and make your move.

This rule does not come easy to any player at any level!


Discovered attack in quiescent search I'm implementing quiescent search in my chess engine, although just capturing moves have been generated. In the below position, at 1 ply, the white queen captures the pawn, but the quiescent search can't see that after 1... Bg3+ 2. Kf1 Rxd5, and the white queen is captured. This is a case of a discovered attack. How can quiescent search handle that, or is it just for capturing moves?
[FEN "2b1k3/3r4/3b4/3p4/8/8/3Q4/R3K3 w - - 0 1"]

Quiesence search isn't able to handle situations like that - including checks would explode the search tree.  Two iterations later (assuming you're doing iterative deepening), Qxd5 and Bg3+ will take place in the main search, and then quiesence search would be able to find the continuation you described.
Some engines include quiet checks in the first ply of quiesence search - in that case you situation would be resolved in one additional iteration instead of two


Why the analyzer propose this move? My move was Kxc3. The move was labeled as a blunder. Why?

Simply put, Kxc3 loses a piece or the exchange after Rc8.

[fen "1n3rk1/5pp1/4p2p/8/q1N1QP2/Pnp4P/1PK2PP1/3R1R2 w - - 0 0"]

1. Kxc3 Rc8 2. Rd6 {or any move} Na5 3. Rd4 Qb3+ 4. Kd2 Nxc4+


When are games against engines drawn? When two engines play against each other in a game of chess, when is it appropriate to declare a draw when clearly no progress is possible?

For example:
8/6k1/8/R3K2p/2r3p1/6P1/7P/8 w - - 0 2

This was a position reached against two engines I am having compete. It has been going on for a while and I doubt a win is possible. Repetition seems like a while away, and I think the fifty-move rule only works if a player requests for it (these engines don't do that). I can't even declare this a draw by endgame tablebases because it has 8 pieces.

Try the TCEC adjudication rules, adapted for your situation. You can use more aggressive (or less aggressive) adjudication rules if you need them, e.g. by changing the threshold eval needed for adjudication.
Win adjudication:

Game ends in a win if there is a mate, engine resigns, time runs out, there is a crash, illegal move, by 6-men TB adjudication, or by the TCEC winrule: both playing engines have an eval of at least 10.00 pawns (or -10.00 in case of a black win) for 5 consecutive moves, or 10 plies - this 10/10 rule is in effect as soon as the game starts. In the website this rule is shown as "TCEC win rule" with a number indicating how many plies there are left until it kicks in.

Draw adjudication:

A game can end in a draw by three-fold repetition, 50-move rule, stalemate, 6-men TB adjudication, and the "TCEC draw rule" (ending the game at move 35 or later if the evals from both playing engines are in [-0.15, +0.15] for 10 plies without a pawn advance or any capture).


Why is Carlsen criticized for poor preparation at World Chess Championship 2018? As of 2018-11-24, 11 games have been drawn at the World Chess Championship (WCC) 2018. A lot of commentators (in particular Alexander Grischuk) have attacked Carlsen for poor preparation.

But ... 11 games have been drawn. It's not like Carlsen is losing. If it's true that he is not well-prepared, what does that say about Caruana's inability to take advantage of that and win? Should he not be criticized for not being able to win against a supposedly ill-prepared player?

In fact, if Carlsen can manage to win this WCC without preparing too much, that's a ... success, isn't it?

Carlsen is being criticized for his preparation with white, particularly e4. He knows that Caruana is going to play the Petrof yet nevertheless Caruana equalizes effortlessly. Carlsen appears to have no new ideas in this opening. Since there is no more important competition he could be saving novelties for it tells us he has no novelties. No novelties = poor preparation. If he doesn't have an answer to this he shouldn't play 1. e4

Note that we have seen novelties from Caruana, not necessarily good ones. As black in one game he played Rd8 in a Queen's Gambit looking to provoke the reply Nd2 from Carlsen. That looked like it would be a strong response from Carlsen but he chickened out and played a much more drawish move suggesting that he believed Caruana had some big improvement planned.


Identify a problem where a potentially winning move draws because of the 50 move rule I'm trying to recall a particular chess problem. It's related to retrograde analysis. All what I can remember is this: it's an endgame where there is only one way to reach the position, and during last 49 moves there were no captures, so a potential winning move draws instead.

There are dozens of problems that illustrate a potential winning moves that instead leads to a draw because of the 50 move rule.

One example is the following mate in four published by Léon Loewenton in 1956 :

[fen "5KBN/p2ppp1r/1p4pp/b7/RP6/1PP4P/1RpPPPkP/n1B1Q1N1 w - - 0 1"]

1. Nf3 Rg7! 2. Kxg7! (2. Qg1+?? draws)

There is an apparent mate in three moves: 1. Nf3 followed by 2. Qg1(+) and 3. Qg3 mate.

However, after 1. Nf3 Rg7! 2. Qg1+ black claims a draw according to the 50 moves rule (the retrograde analysis is left as an exercise to the reader!).

If white plays 2. Kxg7!, the capture breaks the 50 move chain and white can mate with 3. Qg1(+) followed by 4. Qg3 mate.


What does it mean to call a line "sharp"? I am a chess newbie and I was watching a video on four knights opening and the person was discussing another variation and he said that one is dramatic and quite sharp.  From what I saw, it seems "sharp" means immediate mating threats.

Wiki has this:

"Risky, double-edged, highly tactical. Sharp can be used to describe moves, maneuvers, positions, and styles of play."

https://en.wikipedia.org/wiki/Glossary_of_chess#S

That definition, if correct, is still sort of vague for me.  Does it mean Kasparov plays sharp because he was very good at tactics?  Or if you go for Scholar's Mate, does that mean you're using a sharp line?  Can someone elaborate on the meaning of sharp more, like what makes a line sharp, maybe with examples?  Thanks.

A sharp position is one where every move is critical and any mistake could be your last; in such positions basic principles take a back seat to calculation. The opposite of a sharp position is a calm position, where you have time to maneuver as you please and arrange your pieces as you want before initiating confrontation.


Why is better for white to move Rxa7 instead of Nxd3? I am trying to analyze the below middle game with White to move. I played Nxd3 to capture Black's queen. However, the engine analysis says that a better move is Rxa7.
[FEN "r5k1/r4pp1/3P3p/8/8/1p1qP1P1/1Np2P1P/R1R3K1 w - - 0 1"]

If I stick to my play, I expect the these moves-1. Nxd3 Rxa1 2. Rxa1 Rxa1.
White would gain a queen and a rook, while Black will gain two rooks.
If I follow the engines suggestion, I expect the these moves- 1. Rxa7 Qd5 2. Rxa8 Qxa8. White would gain two rooks, while Black will gain one rook.
From the perspective of white, wouldn't it be better to capture the Black queen? Black certainly seems to have a stronger position, but letting the Black queen go seems counterintuitive to me. I am certainly missing something and would appreciate your insights here.

Both rooks control White's back rank. If they are removed through:

Nxd3 Rxa1
Rxa1 Rxa1

Then both pawns cannot be stopped at the same time by the single knight, guaranteeing Black a Queen-Rook endgame. Let's assume White plays Kg2 next:

Kg2 c1=Q
Nxc1 Rxc1

Then the pawn at b3 will surely become a Queen. A worse move but still wins:

Kg2 b2
Nxb2 c1=Q

Because Black still has a Queen and the rook versus White's only minor piece, the Knight.

We also should notice White's passed pawn at d6. So even with d7:

d7 c1=Q+
Nxc1 Rxc1+
Kg2 Rd1

Rd1 prevents White from promoting:

d8=Q+ Rxd8


Taking the knight on c6 in open Sicilians Why is it generally uncommon (unsound?) for white to capture the knight on c6 in open Sicilians?

For example (this is just an example; I'm not referring to this specific position, but similar positions in the opening from Dragons, Najdorfs, Sheveningens, Richter-Rauzers, etc.):

[fen ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 Nc6 6. Nxc6

I understand that not capturing the knight gives black the semi open c-file. But at the same time, capturing closes that c-file and gives it an isolated a-pawn and a semi-open b-file. Is it just because giving away the b-file to black is more dangerous than giving the c-file? I also understand that capturing the knight gives black an extra pawn in the center. But shouldn't white be able to quickly castle on the king side and torment black's a-pawn?

White's d4 Knight is his best piece. Why would he trade it for a common Knight and improve Black's center?

Regarding harassing the a pawn... you can have it.  While you're doing that, your opponent will be drawing a bead on your King.

Checking 365chess.com, we see that Nxc6 is a blunder at the sub-master level.  Black wins twice as often.

At the master level, Nxc6 is not played.  There are 2 games, the latest being from 2004.  Both ended with wins for Black.

The first game is from 9/4/2001 at Glifada.  It's an ECO B56.  Andreas Kofidis is White. Marijan Petrov is Black.  White is completely destroyed in this short game after Black sacrifices a Knight on f3.  Very nasty...

Edit - ...but survivable.  White lost instantly on 17. Bxf8. It's hard to believe he didn't see the mating attack since it's pretty easy.  So he must have though he was already lost.  Instead, 17. Qe3 holds.

[fen ""]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 d6 6. Nxc6 bxc6 7. Bd3 g6 8.  b3 Bg7 9. Bb2 Qa5 10. O-O Ng4 11. Qe1 O-O 12. h3 Ne5 13. Na4 Nf3+ 14. gxf3 Qg5+  15. Kh1 Qh4 16. Bxg7 Bxh3 17. Bxf8 Bg4+ 0-1

This game is from 3/7/2004.  It's ECO B58.  Albert Bokros is White.  Veniamin Sergeev is Black.  Sergeev puts his Queen out there and Bokros tries to trap it.  It doesn't work out, and by move 22 Sergeev dominates the center.  White seems to be trying a cheap shot mate-in-one on move 33. Perhaps he's under time pressure.  It doesn't work out and he drops a piece.

Edit - I see now that the Knight on a5 is trapped. Black piles on the pieces until it falls.

[fen ""]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 d6 6. Nxc6 bxc6 7. Be2 e5 8.  O-O Be7 9. f4 exf4 10. Bxf4 Qb6+ 11. Kh1 Qxb2 12. Qd2 Qb4 13. Rab1 Qc5 14. Na4  Qa3 15. Nb2 O-O 16. Nc4 Qc5 17. Be3 Nxe4 18. Qe1 Qd5 19. Bd3 Qe6 20. Na5 d5 21.  c4 f5 22. Bc2 Ba6 23. Bb3 dxc4 24. Bc2 Kh8 25. Bd4 Bf6 26. Bxf6 Rxf6 27. Bxe4  Qxe4 28. Qb4 Rg8 29. Rbe1 Qd5 30. Rf3 h6 31. Qc3 f4 32. Rf2 Rf5 33. Re7 Qxa5  34. Qh3 Re5 35. Rxe5 Qxe5 36. Qf3 Qe3 0-1

But what's important in both of these games is that Black is granted counter-play out the wazoo - a Sicilian player's dream.  We see Queen sorties in both games on the a5-d8 diagonal.  The b6 square allows the Black Queen to get a bead on the traditionally weak (yet dangerous!) b2 square and also peer menacingly at the castled enemy King.


Castling long in the King's Indian Defence (for white) When does white do it? Why does white do it? What kind of strategies should both sides adopt in such games? What kinds of games does it give rise to (i.e. positional or tactical)? Which players are well known practitioners of such a setup as white?

The most common way to end up with queenside castling for white in the KID is via the Saemisch Variation 5.f3. Black often attacks on the kingside in the KID, and the Saemisch is typically a way to avoid that, and ideally to attack on the kingside oneself. Of course, whole books have been written about what's going on in this variation, and I don't play either side of it myself, so this answer only addresses the last part of your question, concerning well-known practitioners.

The link above notes that

  The Sämisch has been played by numerous grandmasters, including world champions Mikhail Botvinnik, Mikhail Tal, Tigran Petrosian, Boris Spassky, Anatoly Karpov and Garry Kasparov.

True enough, and so did Alekhine. But if my database is to be trusted, none of these champions has all that many games on record in the Saemisch, and even less against serious competition. For instance, Karpov played such a setup twice in his 1990 world championship match against Kasparov, scoring a draw (round 21) and a win (round 23), which is a nice endorsement. But he seems not to have played that way often; in my database, the only other classical game for Karpov in this setup against a player who is truly a peer of his is a draw against Timman from round 18 of their 1993 FIDE championship match.

The late Svetozar Gligoric has 18 games on the white side of this in my database (scoring 12.5 points), and his games could be particularly enlightening since he was a well-known proponent of the black side of the King's Indian; in fact, I also see him scoring 22.5/37 on the black side of this, so there's plenty of Gligoric games from boths sides to chew on.

But the most frequent assayer that I find is Florin Gheorghiu, and he's also a very successful one, with a phenomenal 35.5/43 score. So if you want a "hero" to follow for this kind of setup, Gheorghiu might fit the bill nicely. (Or conversely, if you want to know what might be coming at you as black.) To whet your appetite, what follow are two of his wins, each with Gligoric playing black in fact. The first is from the 1966 Havana Olympiad:

[FEN ""]
[Event "Havana ol (Men) fin-A"]
[Site "Havana"]
[Date "1966.??.??"]
[Round "4"]
[White "Gheorghiu, Florin"]
[Black "Gligoric, Svetozar"]
[Result "1-0"]
[ECO "E87"]
[EventDate "1966.10.25"]
[PlyCount "81"]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5 7.d5 Nh5 8.Qd2 f5 9.
O-O-O Nd7 10.Bd3 Ndf6 11.exf5 Bxf5 12.Nge2 Qd7 13.g4 Bxd3 14.Qxd3 e4
15.Nxe4 Nxe4 16.gxh5 Nc5 17.Bxc5 dxc5 18.hxg6 Rae8 19.gxh7+ Kh8 20.Nc3
Bh6+ 21.Kb1 Re3 22.Qg6 Qg7 23.Rhg1 Rfxf3 24.d6 cxd6 25.Rxd6 Rf8 26.Nd1
Ref3 27.Qxg7+ Bxg7 28.Rg5 b6 29.a4 Kxh7 30.a5 Bd4 31.axb6 axb6
32.Rxb6 Re8 33.Rg2 Re4 34.Rc6 Rh3 35.Rd2 Kg7 36.Nc3 Re1+ 37.Kc2 Kf7 38.Nb5
Be3 39.Rd7+ Ke8 40.Rb7 Re2+ 41.Kb1

And the other is from the 1968 Lugano Olympiad:

[FEN ""]
[Event "Lugano ol (Men) fin-A"]
[Site "Lugano"]
[Date "1968.11.03"]
[Round "10"]
[White "Gheorghiu, Florin"]
[Black "Gligoric, Svetozar"]
[Result "1-0"]
[WhiteElo "2520"]
[BlackElo "2575"]
[ECO "E87"]
[EventDate "1968.10.17"]
[PlyCount "95"]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5 7.d5 Nh5 8.Qd2 f5 9.
O-O-O Nd7 10.Bd3 Ndf6 11.Nge2 fxe4 12.Nxe4 Nxe4 13.Bxe4 Nf6 14.Bc2 Bf5 15.
Ng3 Bxc2 16.Qxc2 c5 17.dxc6 bxc6 18.h4 Qa5 19.Kb1 e4 20.h5 Qe5 21.Nxe4
Nxe4 22.Bd4 Qe7 23.Bxg7 Kxg7 24.h6+ Kf7 25.Rhe1 Rae8 26.Rxe4 Qf6 27.Qa4
Rxe4 28.fxe4 Rc8 29.Qxa7+ Qe7 30.Qd4 Re8 31.Rf1+ Kg8 32.Rf4 g5 33.Rf5
Qxe4+ 34.Qxe4 Rxe4 35.Rxg5+ Kh8 36.Rg7 Re6 37.Rc7 Rxh6 38.Rxc6 Kg7 39.c5
Rh1+ 40.Kc2 dxc5 41.Rxc5 Rg1 42.Rg5+ Kf6 43.Rg8 h5 44.Rf8+ Kg5 45.Rf2 Kg4
46.Re2 Kg3 47.a4 h4 48.a5


How to respond to the Taimanov attack in the Benoni? [FEN ""]
  1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.f4 Bg7 8.Bb5+

How can black respond in the following position?

8...Nfd7 is the most popular line among Grandmasters.

Bareev vs Topalov 2002, 0-1

Bostari vs Polgar 2011 0-1

8...Nbd7 is extremely risky and requires thorough preparation. White does seem to get at least a minimal endgame advantage in the 8...Nbd7 line with best play by Black. Since the advent of strong engines, Grandmasters have avoided it and I would recommend avoiding it as well.

8...Bd7 is just bad and White easily gets an advantage.

I provide some sample lines -

     [Event "8...Nfd7 is Black's best move"]
     [Date "2014.10.26"]
     [FEN ""]

     1. d4 Nf6 2. c4 e6 3. Nc3 c5 4. d5 exd5 5. cxd5 d6 6. e4 g6 7. f4 Bg7 8. Bb5+
     Nfd7 (8... Nbd7 9. e5 dxe5 10. fxe5 Nh5 11. e6 Qh4+ 12. g3! (12. Kd2?! fxe6 13.
     dxe6 O-O 14. exd7 Bxd7 15. Bxd7 Rf2+ 16. Nge2 Rd8=) 12... Nxg3 13. hxg3 Qxh1 14.
     Be3 Bxc3+ (14... O-O 15. exd7 Bxd7 16. Bxd7 Rfe8 17. Bxe8 Rxe8 18. Qe2 Bh6 19.
     Kf1 Bxe3 20. Qg2) (14... Qg2 15. exd7+ Bxd7 16. Bxd7+ Kxd7 17. Qg4+ Kd8 18.
     O-O-O) 15. bxc3 a6 16. exd7+ Bxd7 17. Bxd7+ Kxd7 18. Qg4+ f5 19. Qf3 Qxf3 20.
     Nxf3) (8... Bd7? 9. e5 dxe5 (9... Qe7 10. Qe2 dxe5 (10... Nh5 11. g4) 11. d6)
     10. fxe5 Nh5 11. Nf3 O-O 12. Bxd7 Nxd7 13. g4) 9. a4 O-O (9... Qh4+!? 10. g3 Qe7
     11. Nf3 O-O 12. O-O Na6 13. Re1 Nb4) 10. Nf3 Na6 11. O-O Nb4 12. Re1 a6 13. Bf1
     Re8


What happened to the Chess Cafe website? I have followed the Chess Cafe website for years, but it appears that the website hasn't updated since late May, and clicking on some of the links sometimes leads to a 404 error message. Does anyone know what happened to the Chess Cafe website?

Chesscafe announced on June 2 that the number of subscribers was too low to sustain the site and that they would go on a three month hiatus.

Whether they will ever come out of it again is anybody's guess.


Choosing the best move in the given position I was just guessing the best move in the position.(white to move).

I thought Rc1 would be the best move forcing white to exchange the white's dark square bishop and preserving the white's light squared bishop to neutralize the black's light squared bishop . But the engine gives Bxc2 which doesn't makes as sense as the former.I want to know the idea behind engine's move.

[FEN "r3kb1r/pp1q1pp1/2p1p3/3nPb2/3P1N1p/PBN1BQ1P/1Pn2PP1/R2R2K1 w - - 1 1"]

After 1. Rac1, Black has the intermediate move 1...Nxc3, attacking the rook on d1, which forces White to play 2. bxc3, and then the pawn on a3 is hanging. So Black would likely go 2...Nxe3 followed by 3...Bxa3.

[FEN "r3kb1r/pp1q1pp1/2p1p3/3nPb2/3P1N1p/PBN1BQ1P/1Pn2PP1/R2R2K1 w - - 1 1"]

1. Rac1 Nxc3 2. bxc3 Nxe3 3. null Bxa3


Analysing Positions in Databases with a program I've got two questions. I'm wondering if:

It is possible to search for certain positions in a database (like Chessbase) and display all of them in a text file.
To be able to assign a score to each position automatically with a chess engine.

I've got some notions of programming but I wouldn't mind getting some ideas on how to write such a program.

I am the author of pgn-extract and, as has been pointed out, it doesn't hook up directly with a chess engine. However, if you would like to try out something I recently wrote that does interface with an engine then there is a description of a UCI-based analyser that can output annotated PGN via its --annotatePGN option. It is still a little experimental and you will need to compile from source but it might provide something close to what you are looking for.


Which classical players' games should I check if I want to analyze positional players? I am regularly analyzing games of grandmasters and now I want to check the classics. Who do you recommend to me as a positional player? Thanks.

Smyslov
Fischer
Karpov
Keres
Anand
Kramnik


Determining trusted chess sources? When reading chess articles or watching videos online, my criteria for often determining if it is worth reading or watching is if it is made my someone with a FIDE title (IM, FM, GM, etc), but what other criteria should I use to determine if someone or something is worth reading or watching?

Some that I can think of myself are:

The author of the article/video has a FIDE title.
The website where articles or videos are found has a large following.
The author is relatively widely known even if they don't have a FIDE title.

Also, are there any red flags that should indicate that if I watch or read this, I probably will get incorrect/stale information?

Here are some ideas about whether or not a source can be trusted.
-Not all titled players are good in teaching.
-Chess.com is great because its members are excellent chess players and will not allow a poor article or video to be published.
-chess.about.com is good because it hires professional people, but not as good as chess.com
-thechesswebsite.com is great because kevin (the man behind the site) has many subscribers on youtube, kingcrucher is another great youtube channel because it offers in depth analysis, but they focus too much on blitz.
and then you have Roman's lab, Roman is the greatest chess teacher of all time.
What else do you have? When looking at books, you can check the Amazon rating and reviews.


Is there a Windows based command line tool to convert cbh to pgn? I see that there is code for an Android app available at https://code.google.com/p/cb2pgn/, but I wonder if anyone has taken the time to make a standalone .exe that does the job?

If you have Chess Assistant (CA), it will do the conversion for you.  For example, within CA just right click game on the game and go to Edit --> Copy to Clipboard and pick pgn.


Does the winner of the women's Oceania Zonal qualify to play in a world championship match? The brochure for the upcoming Oceania Zonal in Guam states:

  The winners of the 2019 Guam Zonal qualify and are entitled to advance to play in the World Cup and the World Chess Championship.

I'm unclear on what exactly this means for women's chess.  (Men go into the World Cup, which seems clear enough.)

Last year, WFM Kathryn Hardegen represented Australia in the November 2018 Women's World Chess Championship, and came second in the 2017 Oceania Zonal (crosstable) but the winner WFM Layla Timergazi didn't play in the Women's World Chess Championship, so Kathryn Hardegen played instead.

However, this was a knockout tournament; WFM Hardegen was knocked out by GM Ju Wenjun (who went on to win this tournament) in round 1.

However, as I understand correctly, FIDE is changing the format to no longer be a knockout tournament.  Wikipedia writes:

  The match marks the return to a match only format for the title with qualifying Candidates Tournament, after new FIDE president Arkady Dvorkovich expressed his dissatisfaction for the knock-out tournaments and its frequent different world champions.  ...  The newly established candidates tournament starts on 29 May 2019 in Kazan, Russia. The format is an eight player double round-robin tournament.
  Women's World Chess Championship 2019, Wikipedia

So if the candidates tournament is an 8-player round robin, it can't have all the zonal winners.

Question: Does the winner of the women's Oceania Zonal qualify to play in a world championship match?

It would seem not. According to this document from FIDE:

  Qualification for the 2019 Women’s Candidates Tournament
  3.1. Players who qualify for the Women’s Candidates Tournament are determined according to the following criteria, in order of priority:
  Women’s World Championship KO 2018;
  Three (3) players who reach the semi-finals of the 2018 Women’s World Championship (excluding the Women’s World Champion 2018 who qualifies directly to the World Championship Match).
  Winner of the Women’s World Championship Match 2018 (GM Ju Wenjun);
  Average FIDE Rating of the 12 monthly lists starting from 1st January 2018 to 1st
  December 2018.
  Four (4) players will qualify by their average rating.

Zonal qualifiers are nowhere on this list.

My best guess is that the brochure you linked was created before the changes to the championship were made. The brochure says that countries may nominate players for free entry before October 31 2018 (implying the brochure was created before that date), and this article from FIDE announcing the Women's Candidates Tournament is dated November 21 2018.


Wrong lines of play to illuminate right lines De Firmian's Modern Chess Openings is a good book. I like it. However, the book teaches right lines of play. It teaches few wrong lines.

Should one not also study wrong lines—the blunders, the pitfalls, in otherwise good openings—to learn why the right lines are right?

If so, then how can one go about studying the wrong lines?

[FEN ""]
[TITLE "Example: Sicilian Defense, Accelerated Dragon variation"]
[STARTFLIPPED "1"]

1. e4 c5
2. Nf3 Nc6
3. d4 cxd4
4. Nxd4 g6
5. Nc3 Bg7
6. Be3 Nf6

If an example helps, then see the defense diagrammed above. De Firmian gives Black the right moves in the right sequence, which is nice; but his book apparently lacks space to explain also why Black should not, say, venture Nf6 earlier than move 6. I believe that de Firmian knows why not, but his book is not conveying this knowledge to me.

This tells me that I am probably using the book improperly.

Merely memorizing the right moves seems insufficient. I wish also to grasp why wrong alternatives are wrong. By what method can I study wrong moves for this purpose? How do you do it, please?

(If you answer, then please feel free to give whatever example you like. You need not speak of the Accelerated Dragon. I have arbitrarily diagrammed the Accelerated Dragon merely to put a concrete opening on the board for purpose of illustration, in case this helps.)

A healthy approach towards learning openings is to retain the key ideas involved, and not to necessarily memorise move by move unless it's an extremely precise sequence in a very theoretical line (as is often the relevant case at high level chess). It's a bit analogous to how one would learn physics, by understanding the principles, drawing connections between them, learning to how reason with them and so on, such that ultimately, you can reconstruct theorems in your head, as opposed to memorising them symbol by symbol.

Now in chess, understanding the ideas in the opening phase simply starts by asking yourself questions when you're exploring an opening: for example: "what is the point of an early h6 here? what I am preventing and why is it with such priority?" or "what is Qc2 achieving in this situation? can't I achieve the same with Qd3?" or "Could I not have played Nf6 first without loss of tempo?"  and so on.

In trying to answer those questions for yourself, you will automatically uncover the pitfalls, or the wrong/less optimal alternative moves, without necessarily seeing them listed in a book. Now of course one can never exhaustively do so, as there are simply too many variations in each opening or certain very hard to grasp ideas involved, and that's why there are thick books written on almost every opening, but that said, the essential part of any improvement you are going to make, will result from the struggle of trying to understand a position on your own. It is this struggle that will form your mindset for how to reason about openings in general, one that will continuously evolve for as long as you study chess.

Now in order to find the answers to the type of questions I had mentioned earlier, you need to consider two important aspects: a) a general strategy in mind for what the opening is trying to achieve, b) a concrete assessment of the variations involved such that the strategy in a) can be efficiently implemented, i.e., avoiding redundancies or other loss of tempi, not creating weaknesses or easy targets, and worst case avoiding blunders. This is the part where engines can immensely simplify the task.

Both are equally important. Luckily, the bulk of opening theory we have stems from human play and not computers, meaning players at some point attempting to tackle a certain move differently by emphasizing a set of key new ideas. Luckily, because it means we have a chance of understanding them if we manage to trace the original ideas.

In your example: the essential part of the Dragon variation for black in the Sicilian is the fianchetto'ed bishop on g7. Simply put, unlike most other Sicilian variations where the dark-squared bishop has very little active scope (instead being developed as a purely defensive piece), the Dragon is an alternative that provides more active prospects for the bishop, with a safe developement (fianchetto - making it hard to trade/challenge the piece) and with a follow-up that emphasizes undermining white's dark square control. This is a rough sketch that goes along the point a) we were discussing above. Now more along point b), namely the more concrete aspects of the opening, contains the answer to your Nf6 question: by not playing Nf6 too early you i) entertain the possibility of potentially developing the bishop to g7 with tempo, as it will directly eye the d4 knight and ii) you prevent the option of an immediate e5 from white.  As you show, Bg7 forces a reaction such as Be3 and then you include Nf6 (rendering immediate e5 less critical after Nxc6, see diagram) Whereas with for example 5...Nf6 (so before the bishop), you allow white an easy path to playing e5 closing down the long diagonal and dislocating your f6 knight. The comparison is illustrated below:

 [title "Importance of early Bg7 in Dragon"]
 [fen ""]

 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Nc3 Bg7 (5...Nf6 6. Nxc6 bxc6 7. e5 Ng8 {without tempo, white is free to develop aggressively, no tempo invested on Be3 or on the defense of e5} (7...Nd5 {with 5...Bg7 and Be3 included, this is a good gambit, with about equal play} 8.Nxd5 cxd5 9.Qxd5 Rb8 10.e6! fxe6 11.Qe5 {forking black's rooks : this tactical shot wouldn't be available after 5...Bg7}) 8. Bc4 Bg7 9. Qf3 e6 {rather forced} 10. Bf4 {white is objectively better as they have fully developed, they have the better minor pieces with central control, they have induced important dark square weaknesses in our position by forcing e6. Instead, black is critically under developed and without any real active prospects.}) 6. Be3 Nf6 7. Nxc6 bxc6 8. e5 Ng8 {the knight is retreated with tempo as e5 is under attack. Sure it's a bit slow, but black has a healthy pawn structure, a target on e5, and a relatively easy development to follow. Two main variations exist here, 9. Bd4 Qa5 and 9. f4 f6, see Kasparov-Ivanchuk 2002 for a nice example. }

So you see, by bearing in mind that with a tool such as the Dragon black intends to play actively and eventually for the initiative, and going through the respective variations of 5. Bg7 and 5. Nf6 we've come to the conclusion that Bg7 is the key move here for black in order to not lose pace with white's development/play while keeping active prospects open (make sure to go through the Ivanchuk game I mentioned in annotations).

In fairness, there are much simpler examples to use for the purpose of our discussions. Let's choose a line in the queen's gambit exchange variation (see annotations for discussions):

 [title "example #2: queen's gambit exchange variation"]
 [fen ""]

 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. cxd5 exd5 5. Bg5 c6 6. Qc2 {One wonders, why Qc2 so early? as opposed to e3 for example. In the exchange variation, black often struggles to create active play, and one reason is the c8 bishop which has a hard time of becoming useful. Qc2 is played early to take away the only remaining active bishop move, namely, Bf5!} (6. e3 Bf5 {black has developed their only potentially poor piece in this variation, as it went unchallenged by white.})

In short, in the exchange variation white is committal about the centre early on (cxd5) and continues to play actively with Bg5 forcing c6, followed by the simple usual setup of e3-Bd3-Ne2-f3 setting up e4 push (once castled of course) and a potential minority push on the queen-side. Concretely speaking, you want to achieve all this while not allowing black to develop easily or to create active play. So you start looking more carefully at the position, and only then realise the importance of nuanced moves such as Qc2. You may argue, why can black not play g6 immediately after Qc2 in order to revive the Bf5 idea while preparing to fianchetto the f8 bishop? whether or not a case can be made for that idea, the important thing is that this process of asking these kinds of questions and trying to find the answers to them on your own is how you should learn openings and how you eventually form a mindset for how to think about them in general such that you can even start developing your own systems for facing various things.


How to deal with the pinned knight on f3 in the Ruy Lopez (as white)? I find myself in positions like this a lot when playing the Ruy Lopez:

[fen ""]

1. e4 e5
2. Nf3 Nc6
3. Bb5 d6
4. O-O Bg4

If I try to kick the bishop out with  5. h3, they back up to h5 and I'm in the same spot I was, essentially. What tends to end up happening is after my queen comes out, they take on f3 and I end up with doubled pawns, which makes me pretty uncomfortable on my King's side.

So what's the best way to deal with this pin? Or are doubled pawns a typical consequence of playing this line? Maybe I could have done something earlier? According to the chess.com database, this isn't a super common line anyway.

Black cannot exploit the pin with ...Nd4: not at once because the Nc6 itself is pinned, not later because c2-c3 is on your plan anyway. This means that you should not panic and can concentrate on developing before taking measures about the Bg4.

You should not be afraid of a ...Qf6 either. After the later sequence ...Bxf3, Qxf3, Qxf3, gxf3, your king is secure thanks to the queen exchange, and the bishop pair is much more important than the temporary doubled pawn that you would get rid of by pushing f3-f4, gaining influence in the center in the process.

If you follow a Ruy Lopez plan anyway: c3, d3, Nbd2, Re1, Nf1 you have various ways of breaking the pin.

First, you can move your queen when the second knight is on d2. Plus: it is faster. Minus: your queen don't have so many great square to go to, since on c2 it is a bit passive and that square is better left for a possible retreat of the Bb5.
Second, you continue, after Nf1, with h3 (check whether the opponent can reply ...h5 when his rook is still on h8) and after ...Bh5, Ng3. It is part of your plan anyway (reinforce e4 so you can push d3-d4, possible knight-hops to f5 or h5) and it embarass Black's light-squared bishop. After an eventual ...Bxf3 Qxf3, you gain the bishop pair with excellent chances to build an initiative on the light squares.


FIDE Online Arena: what specifically determines bullet, blitz, rapid, and unmonitored time controls? I've been trying out the FIDE Online Arena; while I've found a lot of marketing, I find very little useful documentation (possibly because the software is new).

FIDE Online Arena has four different Elos: bullet, blitz, rapid, and unmonitored.

Q: What specifically determines bullet, blitz, rapid, and unmonitored time controls?

According to FIDE:

Blitz: <= 10 minutes

Rapid: > 10 minutes and <= 60 minutes

Source: http://www.fide.com/component/handbook/?id=171&view=article (See appendices)

According to Wikipedia and many online chess platforms:

Bullet: < 3 minutes

Blitz: >= 3 minutes and < 10 minutes

Rapid: > 10 minutes and <= 60 minutes

Source: https://en.wikipedia.org/wiki/Fast_chess


Why is the light-squared bishop considered White's best bishop? The same question applies to Black where the dark-squared bishop is considered Black's best bishop.

This was from the book "Logical Chess Move by Move" by Irving Chernev where he quotes Siegbert Tarrasch as saying the King's Bishop is the greatest attacking piece, so I guess it does pertain to mainly one player with one school of thought.  I found it interesting how Tarrasch at times would not even move his King's Bishop during a whole game.

The black king, will occupy e8 and g8 (before and after castling, respectively), both of which are white squares.  Also, the weakest point on the black kingside is f7, again a white square.  Because of this, if you are trying to attack the king, the white bishop can often be more valuable.

Perhaps someone else can add some more deeper reasons, but this has been my experience.

Added: Also worth noting, attacks on h7 can often threaten mate, another white square.  Furthermore, just having the bishop on the diagonal attacking f7 would pin the pawn to a castled king.


Sites which provide annotated openings (preferably interactive) I'm looking for a site that provides well-annotated openings, giving at least the first 15-20 moves of major openings and allowing me to explore their main variations and lines (by clicking on the relevant moves on an online chessboard).
For example, if I am learning Queen's Gambit Declined, I'd expect it to display something along the lines of this (more detailed and expertly annotated, of course, and with a diagram)

1. d4 A popular  opening move, which gives White a solid position. 1. ... d5 Black's reply is quite common, and preserves the symmetry of the situation. 2. c4 This is the Queen's gambit - if accepted, it can provide White great momentum and development. 2. ...e6 Black turns down the gambit  and prefers to keep the position interesting. 2. ...dxc4 is not really got for Black as White can get the pawn back soon by [sequence of moves] followed by a bishop move.

And if I play 2. ...c6, I'd expect something like this (but again more detailed and with a diagram to help.)

2. ...c6 This changes the opening to the Slav defense.

My question
Is there any site online that provides detailed, annotated openings at least 15-20 moves deep and allows me to explore variations and lines (also
annotated)?
Note
The site needn't focus on other parts of the game. I'm focusing on the opening for now.

Wikibook Chess Opening Theory has similar aims but I don't think it quite meets all of your requirements. Still, it's the website closest to meeting them that I can think of, so I hope it helps. Being a wiki, it's still evolving and of course one can always wonder about the expertise of the authors.


Searching for a "where is the black king" problem Sometime ago, a friend showed me a position where he had the Black king removed. The goal was to find where is the Black king using some pretty weird reasoning.
There were only a few pieces on the board and they were quite close to each other in the bottom left corner of the board. Mostly likely, each side has two pawns each, and, maybe two pieces. I'm almost sure that the White king was in double check.
Here are more details that in a spoiler due to hinting at the solution)

The solution (very approximately) is first to find who's move it is. It is obviously White's because of the check, and then from that deduce what Black's last move was. From that, you deduce the king's position. The reasoning was more complicated than the, as it required to go two or three moves backward. This is the gist of the problem.

I have tried to remember the problem, but I can't. Does anyone know a "where is the black king" problem?

What leaps to mind is Raymond Smullyan's problem, and it's to find the White king but possibly it. A retro classic (and one of the few good ones he made.)
8/8/8/1r1b4/B7/8/8/3k4 w - - 0 1

(1+3) Where is the white king?
(Raymond Smullyan, Manchester Guardian, 1957)


How to visualize in chess? Skip to 2:08:27 in this video https://youtu.be/nK4SNEbMn7s.
What exactly is GMHikaru doing that?How can I be able to do that?Does it comes naturally with practice or their are exercises?

Okay, this sequence is very impressive and Nakamura is a "beast". So I don't want to be too pessimistic but I'm afraid that this kind of performance, which consists in calculating at the speed of light a sequence of movements without error, is only possible for the highest rated players.

There is, however, a (little) hope. In the excellent perpetual chess podcast talk, GM Rustam Kasimdzhanov talks about Nakamura. He notices about his play and the play of some of the top teenagers in the chess world, including GMs Nodirbek Abdussatorov and Alireza Firouzja that they never blunder, even under stress, and their tactical perception of the position is extremely clear. The reason could be the thousands of games, especially blitz games, they have played. So go practice!


Caro-Kann Bronstein-Larsen Variation For Black Any good references (books/videos/tutorials) for this variation?

[fen ""]
[StartFlipped "1"]

1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nf6 5.Nxf6+ gxf6

Thanks!

If you read Danish there's Bent Larsen's Solide åbninger (Solid openings) from 1980.

It is a repertoire book for beginners (white and black) and suggests the line you inquire about as the defense against 1. e4.


Queen's Gambit Accepted Nc3 VS Nd2 Usually I play somewhere around move 5-Nc3 but I might start playing Nd2 more instead to get a different dynamic in the game.

Is this advised? Does this have dire consequences in QGA?

Unless you have a good reason, why would you block your own queen bishop and release tension on the important d5 square?

The idea of the gambit is to intensify pressure on the d5 square. Volunteering yourself away by Nd2 is unusual.


How is this move illegal? I'm black and it's my turn. I'm playing in the Arena chess player against Stockfish.
This is my current board:

[fen ""]
[startply "31"]

1. e4 d5 2. exd5 e6 3. dxe6 fxe6 4. Nf3 Nf6 5. Bc4 c6 6. O-O Bc5 7. d4 Bb6 8. Re1 O-O 9. Nc3 Nbd7 10. Ng5 Ne5 11. dxe5 Qxd1 12. Nxd1 Ng4 13. Nxe6 Bxf2+ 14. Nxf2 b5 15. Bb3 Nxf2 16. Nc7+

I want to play Rb8:

1rb2rk1/p1N3pp/2p5/1p2P3/8/1B6/PPP2nPP/R1B1R1K1 w - - 2 17

but I keep getting errors telling me that's illegal.

HOW IS THIS ILLEGAL??


How do you use Sesse? How can I set up a position on Sesse? I've been trying to find a way to set up a position on the blank chessboard for half an hour unsuccessfully. How do you do it?

It doesn't work because there's a bug. If you open the console (F12 → Console) you'll see some errors. It seems that an essential file is missing from the server. Until it is fixed, you should probably use another analysis board.


Underpromoting a pawn Is it legal to underpromote a pawn to opponent's pieces? For example, in the below position, promoting White's pawn to a Black knight will be a win.
[FEN "r7/kPR5/8/K7/8/8/8/8 w - - 0 1"]
[Title "Underpromotion"]

No, it is not.

FIDE Laws of chess, clause 3.7e:

  When a pawn reaches the rank furthest from its starting position it
  must be exchanged as part of the same move on the same square for a
  new queen, rook, bishop or knight of the same colour.


In the Delayed Open Catalan, after 1. Nf3 d5 2. d4 Nf6 3. c4 e6 4. g3 Be7 5. Bg2 O-O 6. O-O dxc4 7. Ne5 c5 8. dxc5 Bxc5, which move should I play? In the Delayed Open Catalan, after 1. Nf3 d5 2. d4 Nf6 3. c4 e6 4. g3 Be7 5. Bg2 O-O 6. O-O dxc4 7. Ne5 c5 8. dxc5 Bxc5, we reach this position:

[Title "White to move"]
[fen "rnbq1rk1/pp3ppp/4pn3/2b1N3/2p5/6P1/PP2PPBP/RNBQ1RK1 w - - 0 1"]

I made 4 of the 5 strongest engines analyze the position for more than 30 minutes each. Here are the results:

It seems all the engines think that 9. Qxd8 (followed by 9... Rxd8 10. Nc3) is the strongest move. And they all also seem to think that 9. Nc3 is the second best move.

But on the book Wojo's Weapons Volume 1, the authors apparently recommend 9. Nc3, although they don't talk a lot about that move (Wojo actually never faced 7... c5, all his opponents answered 7... Nc6 instead).

So which move do you recommend me to play? What are all the advantages and disadvantages of 9. Nc3 and 9. Qxd8 ? Should I put my faith on the engines or on the authors of Wojo's Weapons?

It is a well deserved doubt that you have in this position. As a Catalan player, I like both continuations (i.e. Qxd8 or Nc3) for well defined reasons. First one important note on Catalan openings or similar positions:

White's play evolves around the positional play of minor pieces.

Meaning in any position resulting from a Catalan, you should reason by continuously evaluating your minor pieces development progress versus that of your opponent (less focus on pawn structure as the center is already simplified.). Added to which there's white extremely solid and flexible pawn structure, which means any early end-game transitions should be favored for white.

Now regarding your engine suggestions vs Wojo's version:

The engine of course looks for maximum edge in any position, in this particular one, the immediate endgame transition right after a queen exchange is favored for white, because of the slight edge in development, and there are no tempos to be gained by black, hence the slight + score you see in all evaluations after Qxd8. To showcase one of them:

[Title "Qxd8 example line"]
[StartFlipped "0"]
[fen "rnbq1rk1/pp3ppp/4pn2/2b1N3/2p5/6P1/PP2PPBP/RNBQ1RK1 w - - 0 1"]

1.Qxd8 Rxd8 2.Nc3 Be7 3.Bf4 Nd5 4.Rad1 g5 5.Bc1

It goes without saying that white has the more comfortable position, with all pieces actively in play, better control on d-file, c4, g5 under pressure, and no pawn structure worries for white, whereas black needs to find the right tempos to activate the 3 remaining pieces and all the time cover the weaknesses.

[Title "Qxd8 2nd example"]
[StartFlipped "0"]
[fen "rnbq1rk1/pp3ppp/4pn2/2b1N3/2p5/6P1/PP2PPBP/RNBQ1RK1 w - - 0 1"]

1.Qxd8 Rxd8 2.Nc3 Nbd7 3.Rd1 Be7 4.Nxc4

One example showing black can't just easily activate the pieces after the queen-exchange, after Nxc4, Bg5 coming, constant pressure on b7, better control on d-file...all shows how better (or just more comfortable white is).

Conclusion for Qxd8: If you're comfortable playing this type of middle-game endgame positions, you should definitely try playing the Qxd8 line, a good experience in these lines will greatly improve your minor pieces positional play (finding right squares, covering the right ones, keeping pressure, coordination, etc.). Note that these are not necessarily easy to play positions if you don't have experience in such positions. Often one gets confused where to place the pieces (knight on c4, or e5, or e3 etc... or maneuvers like Nb5 to Nd4 sometimes very handy, point being white can also easily mess up.)

Now regarding Wojo's suggestion: there's a simple reason behind: white intends to keep the queens on, and play for the slight activity edge, without forcing an endgame right off. After Nc3 there are many different lines that can be played, I will show two of them. In the calm ones, white's plan relies on black cramped white bishop, caged rook on a8, and the rather exposed queen of black after Qc7 or  Qb6 etc. Here you have to be good at keeping your slight edge and slow by slow poking at black's weaknesses, and most importantly finding the right time to exchange and simplify the position to leverage the advantage in an endgame.

Before I show the lines, note that after Nc3 black cannot just exchange the queens, because the resulting position after Rxd1 is just a much better version of what white had after Qxd8, since the d-file is completely in white's hands.

[Title "Nc3 example line"]
[StartFlipped "0"]
[fen "rnbq1rk1/pp3ppp/4pn2/2b1N3/2p5/6P1/PP2PPBP/RNBQ1RK1 w - - 0 1"]

1.Nc3 Qc7 2.Nxc4 Nc6 3.Bg5 Be7 4.Nb5 Qb8 5.Qc2

With Rfd1, Rac1 and Nd4 coming up, black is under great positional pressure and will have a very hard time to finish development for a while.

Now one fancy line, where probably white has a great attack with very positive chances (doesn't necessarily mean black is hopeless).

[Title "Nc3 fancy continuation"]
[StartFlipped "0"]
[fen "rnbq1rk1/pp3ppp/4pn2/2b1N3/2p5/6P1/PP2PPBP/RNBQ1RK1 w - - 0 1"]

1.Nc3 Qc7 2.Nxc4 Bxf2+ 3.Rxf2 Qxc4 4.Rxf6 gxf6 5.Bh6 Nd7 6.Bxf8 Kxf8 7.Qd2

Where again white has the initiative with better chances, just look at the activity of each piece...(and the rook coming on f or d-file). This is a fancy and rather complicated line which you can avoid of course if you don't like.

So you see after both Qxd8 and Nc3, it's just a relatively equal game where white has the comfortable play, with easy to find squares for all his pieces, whereas black not necessarily lost, has to keep struggling to finish development without ending up with less pawns eventually. I personally like Nc3 because I usually play these lines with the queens on, and for you, you just have to see which type of lines you prefer to play (or better to say : more comfortable in), this should be your main reasoning when in doubts like "what opening variations to play".

By no means an eval of +0.50 or +0.20 by the engine means winning for white, no one is able to keep such slight edge from the opening, not even the engines, you see these evaluations because they suggest who has the easier play, the initiative and the quicker development, but chess is way too dynamic to allow for such slight edges to suffice in winning a position. I certainly recommend the Catalan opening, and you should try all these lines for yourself at least a couple of times, so that all the ideas discussed above become clear to you.

Let me know if you have any further questions, and if you want to discuss a specific line.

EDIT: I would certainly recommend studying some of the games of Kramnik, Ivanchuk and Carlsen, all playing the white side of this opening. They will be very resourceful to you.


Using a check-preventing piece to protect the checkmating piece Let's say that a piece is protecting my king from check, i.e. blocked or pinned. For example, my rook is in the way of my opponent's queen in checking my king. Can I checkmate their king with another piece, let's say my queen, if my check-preventing rook protects my queen, even though I could technically not move that rook?

Yes- if they captured your queen, then it would count as them going into check:
(from this, ironically listed as a "Related" question here)

Besides making sense, it's also explicitly stated in the rules of the
game:
3.9 The king is said to be 'in check' if it is attacked by one or more of the opponent's pieces, even if such pieces are constrained from
moving to that square because they would then leave or place their own
king in check. No piece can be moved that will either expose the king
of the same colour to check or leave that king in check.
Source: Laws of Chess on the FIDE site


The quickest selfmate in 1 How quickly can a legal game reach a position where one side must
give checkmate?
This is in effect Evergalo's reading (see
his (now deleted) answer)
of Rewan Demontay's Question 33154; that question actually asked
something else, but the selfmate question is nice too.  Evergalo offered
a game that reaches such a position in 6.0 moves, i.e. after Black's 6th:
[FEN ""]

1. e3 d6 2. Ke2 Qd7 3. Kd3 Qh3 4. Qh5 Kd7 5. Ke4 Ke6 6. d4 Qf5+ 7. Qxf5#

I found a solution in 5.5, that is, after White's 6th move
(actually two very similar positions, which together can be reached in
660 ways according to Popeye 3.41).

Is 5.5 moves the quickest possible?

If so, are there other solutions in 5.5 ?

Has this puzzle appeared before?

Going to the dusty databanks in my skull, this indeed has been written about before. It appears in Journey Entry #153 of Tim Krabbe's Chess Diary. Since you define the ply count to the position before the selfmating move, the given examples are valid (although, Krabbe does not count the forcing move either, leading to counts of 5.0). This answers your second and third wonderings.
Here are the given games, which, unsurprisingly, all have Fool's Mate setups. All are 5.5 moves, the same as yours. I can offer no proof of optimality, however. I do think, though, that it seems unlikely that faster can be done.
[Title "Pim Blijlevens, Tim Krabbe's Website #153, 12/10/2001, PG in 6.0"]
[FEN ""]

1. f4 e5 2. g4 Ke7 3. Nc3 Kf6 4. Nf3 Kg6 5. Nd5 Nh6 6. Nh4+ Qxh4#

[Title "Pim Blijlevens, Tim Krabbe's Website #153, 12/10/2001, PG in 6.0"]
[FEN ""]

1. e4 f5 2. Ke2 g5 3. Kf3 Nc6 4. Kg3 Nf6 5. Nh3 Nd4 6. Qh5+ Nxh5#

[Title "Sasho Kalajdzievski, Tim Krabbe's Website #153, 12/11/2001, PG in 6.0"]
[FEN ""]

 1. e4 h5 2. f4 g5 3. Kf2 f5 4. Kg3 gxf4+ 5. Kh3 a6 6. Qxh5+ Rxh5#


Online resources for medieval Persian chess games or problems? I am looking for any collection of chess games of al-Suli or anyone medieval scholar's composition of games. Any resources would be appreciated.

Take a look at   this  page.
I hope it helps..


Has there been a game which was drawn with three queens? One of my friends who follows chess told me that there was a player in the past whose defensive game was so good that he drew a game where the opponent had three queens ? I couldn't find a game like that. Has there ever been a game like that ?

Currently I still can't find a drawn game, but I found a game where white had 3 queens, black had 2 and other pieces, and black won. There was a game on chess.com where black had 0:00.1s left and promoted in time for checkmate (3 queens).

[FEN ""]
[StartPly "137"]

1. Nf3 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. d4 O-O 6. Be2 e5 7. O-O Nc6 8. d5 Ne7 9. Bg5 h6 10. Bxf6 Bxf6 11. b4 Bg7 12. c5 f5 13. Nd2 Kh7 14. Rc1 Ng8 15. cxd6 cxd6 16. Nb5 Nf6 17. Nc7 Rb8 18. Bd3 f4 19. Qa4 a6 20. b5 Nh5 21. f3 Rf7 22. b6 Bf8 23. Qb3 Ng7 24. Rc2 Qf6 25. Rfc1 Bd7 26. Bxa6 bxa6 27. Nxa6 Rb7 28. Rc7 Qg5 29. h4 Rxc7 30. Nxc7 Qxh4 31. b7 Nh5 32. b8=Q Ng3 33. Qc4 Qh1+ 34. Kf2 Qh4 35. Kg1 Qh1+ 36. Kf2 Qh4 37. Kg1 Qh1+ 38. Kf2 Qh4 39. Qb6 Be7 40. Nf1 Qh1 41. Nd2 Qh4 42. Ke1 Qh1+ 43. Nf1 Bh4 44. Kd2 Qxg2+ 45. Kc3 Ne2+ 46. Kb2 Nxc1+ 47. Kxc1 Qxf3 48. Ne6 Qa3+ 49. Kd2 Be7 50. Qcb3 Qa8 51. Qc7 Be8 52. a3 Qa6 53. Qcc4 Qa7 54. Qf3 Bh4 55. Qh3 g5 56. Nd8 Bd7 57. Qhc3 Rg7 58. Nc6 Qg1 59. Kc2 g4 60. Nb8 Be8 61. Nd2 Bg6 62. Qc8 Qg2 63. Nd7 Be7 64. Nxe5 dxe5 65. Qxe5 Bxa3 66. Qcc3 Bf8 67. d6 f3 68. d7 f2 69. d8=Q f1=Q 70. Qde7 Qf7 71. Qxf7 Bxf7 72. Qf5+ Kg8 73. Qfc8 Qf2 74. Qb4 Bg6 75. Qbc4+ Kh7 76. Qxg4 Bd6 77. Qce6 Bb4 78. Qd5 Rc7+ 79. Kd1 Bxd2 80. Qxd2 Qf1+ 81. Qe1 Rc1+ 82. Kxc1 Qxe1+

(white had an advantage but didn't use it properly and hung too many pieces)


Good format for library of chess positions w/tags? I'd like to create a library of chess positions with associated tags. For example, one position might be tagged "Tactics", "Counterplay", and "Knight Forks". The goal is to be able to search the positions by tag to create examples/exercises for a specific idea without spending a huge amount of time digging up new positions. Does anyone know of a program/format that would be well-suited for this?

You could use a MySQL database with a column for the fen string and a column for the category. MySQL pairs well with php, perl, and python depending on what you w
ant to use the database for (such as a website or something you can just use personally through a browser), a WAMP server can make this easier to set up.


What is the most queens that have been on the board in a grandmaster game? There are quite a few grandmaster games with 3 queens or 4 queens, but what is the highest number of queens on the board in a game between two GMs?

I'd be interested in both the most on the board at the same time and the most total during the game.

This sounds like a job for Tim Krabbé, who presents two games with six queens: Szalanczy - Nguyen, Budapest 2009 and Anton - Franco, XXI Elgoibar Magistral 2011. I don't know how many of the participants were grandmasters.

There are some other games with 5+ queens at Chess Siberia. Of these, Miton - Benjamin, World Open Philadelphia 2005 definitely features two grandmasters.


An efficient program, which generates all next moves for all pieces in C/C++ I am looking for an efficient (fast) program to generate next moves for all pieces.

I need it in C++, because I will program in C++.

I think it is unreasonable to ask for this as a stand-alone program because its implementation will be very dependent on the design of your program as a whole. In particular, it completely depends on how you are storing each position: how are you representing the board and pieces? How do you keep track of where each piece is after each move? How do you know which squares a piece can move to (is there a piece there already? Is there a piece blocking the bishop's movement as it goes from c1 to f4?)?

Of course, once you have a implemented all of the above perfectly then the problem of generating the moves that each piece can make becomes quite easy: simply iterate over every piece and for every piece iterate over all of its valid moves (how you store moves is, again, entirely up to you).

Finally, this is a great resource that gives a good overview of some important topics in chess programming.


Using Stockfish in c# android (xamarin) app I looked at this question

Implement a chess app for Android with Stockfish

but it doesn't seem to be answering what I want to ask. Maybe part of my question is topic for stack overflow forum, but anyway, I try it here first.

I'm doing android app in c# with xamarin and would like to use Stockfish for analysis and play functions. I already have c++ class working with PC version of engine (uci) and I would like to reuse some of the code like uci parsing. What steps should I do to run Stockfish in my c# app? Also I would like to ask if there are some conditions under which stockfish can/can't be used in android chess app.

Reusing C++ classes in C# is annoying but straightforward. You'll need to know managed C++.

  https://stackoverflow.com/questions/855756/difference-between-native-and-managed-code

gives you what managed C++ is. It is a C++ technology invented by Microsoft, and it works as a layer between C# and unmanaged C++.

There is no reason why you can't do it in C#. You may want two background threads. The first one sends UCI commands to the engine, while the second thread asynchronously wait for engine results.

EDIT

Steps you should follow:

Read what managed C++ is and why you would need it
Make sure you can compile your unmanaged C++ code (regular C++). How to do it depends on your environment
Make sure your can also compile managed C++ code.
Make sure your C# code can call into managed C++
Make sure your managed C++ code can call into unmanaged C++
Now, you should be able to pass a PGN string from C# to your unmanaged C++ UCI parsing code

There is no reason why you can't use the Stockfish engine in Android.


What are the benefits of learning to play chess as an adult (30s) if any? I played chess when I was a child, but never got into it seriously (I didn't know it was possible at that age). Nowadays I'm playing regularly as a hobby and I'm interested in how this can affect my performance in other aspects of my life (specially in my job as a mathematician and a computer scientist).

Now I know it is highly beneficial to play chess as a child but I wonder if there is any research showing any benefit from learning chess as an adult (it's obvious that professional players and even amateur players are intelligent and have developed amazing mental skills... but they usually start playing at an early age).

Also, what different approaches could an adult take to learn chess? (if there is any research about it).

The benefit I like the most (I'm almost 60) is that it prevents, or slows down the onset of,  Alzheimer's disease.

http://www.nytimes.com/2003/06/24/opinion/checkmating-alzheimer-s.html

http://gambit.blogs.nytimes.com/2010/12/07/can-playing-chess-prevent-alzheimers/?_php=true&_type=blogs&_r=0


Queens Gambit Accepted 3rd move Side Lines (White) What are rationals/inherent preferences behind the following novelties performed by White? I'm open to those to either logically deduced them or explain the deviated lines through experience/practice playing them.

The traditional line:

[FEN ""]
1.d4 d5
2.c4 dxc4
3.Qa4+ Bd7
4.Qxc4 ...

Novelty 1:

[FEN ""]
1.d4 d5
2.c4 dxc4
3.Bf4!?

Novelty 2:

[FEN ""]
1.d4 d5
2.c4 dxc4
3.Nd2!?

Novelty 3:

[FEN ""]
1.d4 d5
2.c4 dxc4
3.b4!?

Short answer

3.Qa4+ and 3.Bf4 are reasonnable enough moves but not dangerous for Black.

3.Nd2?! and 3.b4? are very dubious.

1. "Traditional line"

I don't know why you name it that way, 3.Nf3 or 3.e4 are much more common than 3.Qa4+. By the way your "novelties" are certainly not that "new" either.

The idea of 3.Qa4+ is to regain the pawn at once. Its minus is that the queen goes out too early and will lose some tempi later on. Note that beside 3...Bd7, 3...Nc6 is possible too.

2. "Novelty 1"

3.Bf4 is just a developing move, so it cannot be too bad. However, it doesn't adress the main issues in the QGA (fight for the center, for the light squares, for the Pc4...), so it should be pretty harmless for Black after, say, 3...Nf6 4.e3 c5!?, or 4...Bg4!?, or simply 4...e6 followed by a6,c5 in traditional QGA-style.

3. "Novelty 2"

I suppose 3.Nd2?! aims at taking back on c4 with that knight. Fair enough, but it becomes a real (double-)gambit after 3...Qxd4!? 4.Nf3 [or 4.e3 Qd7 5.Bxc4 e6 and White doesn't have enough for one pawn.] Qc5, and White has to prove his compensation. If Black is less adventurous, 3...Nc6 4.e3 e5 should already be advantageous for him: he has more influence in the center and White hasn't got his gambitted pawn back yet.

4. "Novelty 3"

3.b4? sets a record: There is no faster way to give your opponent a passed pawn after only 5 plies. It also doesn't develop, doesn't make a threat and weaken your queenside.

If Black takes en passant, White will get a bit of compensation for his pawn but probably not enough. If black just develops with 3...Nf6 or 3...e6 (already hiting b4!), he enjoys a great position with as much of an advantage as you can dream for on move 3 as Black. The solid 3...c6 planning either 4...a5 attacking the weakness on b4 or 4...b5 securing an extra protected passed pawn also looks logical to me. 3...e5!? is a more aggressive option, and a tempting one as well since 4.de5 Bxb4+ 5.Bd2 Qd4 6.Bxb4 Qxa1 is probably just winning for Black.

Maybe White's idea is the trap 3...Nc6?! 4.d5 Nxb4?? [even here, 4...Ne5 should be okay.] 5.Qa4+ winning the knight, but well, that's just a cheapo and once Black avoids it he can be very happy.


What kind of gun is Alekhine's gun? This question is about chess linguistics. Alekhine's gun is the pattern where the queen is placed behind two rooks.

Who came up with the phrase?
Is it clear which kind of gun they had in mind?
In which language did the phrase originate?

I always imagined "gun" in this context meant a piece of artillery such as a cannon, because surely the three heaviest chess pieces put together must be a heavy weapon! :-)

I see that several of the non-English Wikipedia articles about it use cognates of cannon, for example, Cannone di Alechin (Italian) or Canhão de Alekhine (Portuguese). But on the Spanish-speaking world, the situation seems more confused: there are more Google hits for pistola de Alekhine than for cañón de Alekhine, and I can't tell which could be considered more authoritative. Could this have been a mistranslation?
 On the other hand, the metaphor of threatening the player across the table with a pistol is also interesting, and I've also seen the queen behind the bishop called Reti's rifle, so maybe there's more of a small arms tradition in chess phrases than I originally thought.

Alekhine's gun is a formation in chess named after the former world chess champion Alexander Alekhine. This formation was named after a game he played against Aron Nimzowitsch in Sanremo 1930, ending with Alekhine's decisive victory.


Board Vision Puzzles There's a plethora of tactics puzzles out there. However, I'm looking for board vision puzzles.
For example, given a certain position, how many legal moves does X piece have? How many pieces are pinned? Which pieces are hanging? Etc...
Here is a great example of the type of puzzle I'd love to find more of.
Does anyone have any resources for these types of puzzles?

[FEN "2Q1Q3/2Q4Q/Q4Q2/3k4/Q5Q1/1R6/B1NBQ3/K2R1N2 w - - 0 1"]

How many mates?
What was black's last move?
hint: this construction (by Anthony Stewart Mackay Dickens, published in The Problemist, Jan 1970) ties the record (set by Nenad Petrovic, Sahovski Vjesnika, 1947), using fewer units.
Happy counting. But, frankly, I doubt this is useful to you...
This is certainly a remarkable diagram from a constructionist perspective, but it was never intended to improve a player's vision (in fact, if anything, such a visualization exercise will lead to blindness).
Stronger players may solve this faster (the guy in the video offers no statistical analysis), but solving faster will not put us among them.
Personally, I doubt that such unnatural mates in one can be a useful training exercise to improve your "vision."
I have no doubt that solving simple combinations and mates (e.g., Polgar's 5334 puzzles book) -- until the common patterns become automatic -- will improve your tactical ability.
A diet of endgames is even better!
Reading miniature games without a board might be the best ways to benefit your visualization (and your opening repertoire).
Another good way to improve visualization is to attempt "word" problems without a board.
For example, consider this problem from Sam Loyd (which I will paraphrase below)...
You took a new job, and just relocated into the wilderness. Your chessboard and computer will not arrive for a week or so. Despite that, you just received a certified letter from your former boss, with whom you reluctantly agreed to keep in contact by way of a correspondence chess game. This arrive early, no doubt, with the intent to put you at some disadvantage. But, no worries -- you have three days to answer the opening move, and who needs a chessboard to answer the opening move?
In the letter, your former boss boasts of needing to make it challenging.
"I play 1. f3," he double-exclaims... and there's more... he also sends the following list of conditional moves: "if legal, I play 2. Kf2, 3. Kg3, and 4. Kh4."
Technically, you need only answer the first move within three days, but despite having no chessboard, you have a strong incentive to spare your cheap opponent the cost of another postage stamp.
Can you find a series of moves which checkmates your opponent on your fourth move?
It is possible, but to find it, you'll need to unlearn everything you know about chess.
Just remember: finding the solution is not the point -- the whole point is to search for mating ideas of your own, and visualize the positions (to confirm your ideas without shuffling wood).


Worst tournament performances of reigning World Champions As a Magnus Carlsen fan, it was a bit disappointing for me to see him finish clear second in Biel 2018, one and half points after Mamedyarov, after starting the tournament with two wins - and it could have been two points - had not the much lower-rated Georgiadis blundered in a drawn endgame. Although not a bad performance per se, I was wondering what were the worst tournament performances of reigning World Champions?

Looking through this list of strong tournaments, among those that stand out are:

AVRO 1938, where Alekhine finished 6/8.
Tillburg, 1996, where Karpov finished 6/12.
1st Grand Slam Masters Final (2008), where Anand finished in last (6th) place.


Why did Andersson waste two tempi in this game? Andersson gives Karpov two tempi (Na6-b4-a6-b4). Understandably, he moved his knight to b4 initially to attack the white bishop. But then he moved it back and forth! It was the 32nd move when he did this, so it is possible that it was due to time. Is there a subtler intention?

Na6-b4-a6-b4 was a waiting strategy. Black lacked counterplay in the position, and there wasn't much else to do. ...Nxf3+ was a possibility but it would just open the g-file for White's rook.


Chess GUI Java Swings code needs fixing My Taken Pieces Panel clusters ugly with the pieces.

Here's my code :

class TakenPiecesPanel extends JPanel {
private final JPanel northPanel;
private final JPanel southPanel;
private final Dimension TAKEN_PIECES_DIMENSION = new Dimension(80, 80);

TakenPiecesPanel(){
    super(new BorderLayout());
    this.setBorder(PANEL_BORDER);
    this.northPanel = new JPanel(new GridLayout(8, 2));
    this.southPanel = new JPanel(new GridLayout(8, 2));
    this.add(this.northPanel, BorderLayout.NORTH);
    this.add(this.southPanel, BorderLayout.SOUTH);
    setPreferredSize(TAKEN_PIECES_DIMENSION);
}

void redo(final MoveLog movelog){
    this.northPanel.removeAll();
    this.southPanel.removeAll();

    for(final Piece takenPiece: whiteTakenPieces){
            final BufferedImage image = ImageIO.read(new File(BoardUtils.ICONS_PATH +
                    takenPiece.getPieceColor().toString().substring(0,1)+
                    takenPiece.toString()+".gif"));
            final ImageIcon icon = new ImageIcon(image);
            /*This didn't work too
            final JLabel imageLabel = new JLabel(new ImageIcon(ic.getImage().getScaledInstance(
                    ic.getIconWidth() - 15, ic.getIconWidth() - 15, Image.SCALE_SMOOTH)));*/
            this.southPanel.add(imageLabel);
            this.southPanel.add(new JLabel(icon));
    }
    validate();
}
}

The images are displayed in a single column and when the number exceeds the column limit, they are displayed in the adjacent column. This is when the panel gets ugly.

I'm a beginner in GUI programming. I've tried increasing the panel size but it won't work. Please help me out.

Your GUI design is bad. I'd just do this:

White pawn x3
White queen x1
Black pawn x2
....

Draw a chess piece and add a number to it's top-right corner. It's like how iOS and Android show the number of unread SMS messages you have.

Nobody wants to count the number of pawns in your panel. Just add a number.


Looking for a chess variant with a circular board I am looking for a certain chess variant played on a circular board.

The variant is played with the usual chess pieces (no fairies involved) on a peculiar circular board. The central part of the board is filled with triangles (alternating black and white) and is part of the playing field. The outer rings are made of only slightly deformed squares. The board was checkered (alternating black and white fields).

A particular feature of the Chess Variant I'm looking for is the movements of the bishop: It changes colour when moving across the centre of the board (a diagonal step is analysed as one step forward followed by one step orthogonally sidewards). Also the Knight has very peculiar moves in the centre of the board.

I remember to have seen a description of this Chess Variant in a German student's newspaper in the 1980s (probably issued by Fachschaft Physik at Ruhr-Universität Bochum). I was not able to retrieve this variant anywhere, it is AFAIK not in the "circular board" category at http://www.chessvariants.org

EDIT: it is a two-player variant (I thought of this as a default and didn't mention it explicitly). The rooks moved either radially or orbiting around the circles.

I'd like to know: Name of the variant, name of the inventor and date of first publication, full ruleset (initial position, exact board and rules).

EDIT2: The number of the triangles in the central disk must be divisible by 4 (it's probably 16) because triangles of the same colour face each other. Another feature of the bishop's movement I remember again now: A bishop crossing the centre can actually choose two different continuations because the diagonal movement can be achieved following two different "staircases" of alternating orthogonal moves.

A few suggestions:

This looks sufficiently circular and weird, though I didn't find the rules.

For three people.

And there is apparently a circular citadel chess, with triangles in the middle.


Continuous evaluation of engine in ChessBase I just bought ChessBase 13 and downloaded Stockfish, but when I am analyzing my games there is no continuous evaluation of the moves. So say I make 3 extra moves, the engine is still calculating the position 3 moves before. How can I change so that the engine automatically calculates the position on the board, so that it will go along with the moves?

Hope you can help!!

I bet you turned on the "Lock engine" toggle, which tells the engine to keep analyzing the position it's on even when the board changes. There's a padlock icon in the engine window. Try clicking it so the padlock is open.


A mate in two problem [FEN "8/8/4R3/8/2kBn3/K2pQ3/8/8 w - - 0 1"]

1. Re5?

With White to move, here is a mate in two problem that I couldn't figure out. My opinion is that the first move is 1. Re5, but Black still has a variety of moves. Does anyone have better ideas on how to solve it?

With the rook on e6, Bb6 is mate in two. For instance

Bb6 d2 2. Qb3 mate
or 1. ... N any 2. Qc5 mate
or 1. ... Kc3 2. Qc1
or 1. ... Kc5 2. Qxd3
or 1. ... Ke4 2. Qxe4


Looking for a chess engine that instead of playing the best move randomly chooses among the best moves? Of course this should be subjected to some rules; something like "play any move that's not bellow 0,70 the best move", or something similar.
My idea is to use such an engine in order to play some unorthodox openings without needing an opening book.
For example, say I want to play some games as White trying 1.e4 e4 2.a3. I'm sure there are many good moves for black's second move, so I'd like the engine to "choose" from several of them, instead of always playing the best one.
Kudos if this behavior could be limited to a fixed number of moves -so you get some variety in the opening but you want it "full power" on middle and endgame.

There are few engines that are capable of such thing. One name that I can recall is the old Spark UCI engine by Allard Siemelink.
Very aggressive engine with twistable attacking parameters.
It has a feature called MultiPVMargin which enables you to set certain number difference between the PV (Principle Variations) measured in centipawn.
For example if your best calculated variation in certain position is measured as +1 for white and you want the engine to play something less "valuable" than that, you can set the MultiPVMargin to a 100 so that the engine looks for a different variation within the 100 centipawn difference.
You can find older versions of the Spark engine that are available for free download.
Hope this was the answer you were looking for!


On an infinite board, which pieces are needed to checkmate? Most of the winnable endgames require cornering the opposing king to checkmate, often using zugzwang. However, if you have an infinite board (infinite in every direction), you won't be able to corner the opposing king as easily, as they will be able to retreat unless there is a threat behind them. For example, queen vs king will be a draw in this scenario, as the king and queen will never cover all escape routes. I also believe that two rooks will be unable to deliver mate, as you cannot force opposition. However, queen and rook will be able to checkmate, by using the queen to create a "corner" and checkmating using rook and king. In general, if a combination mates in a regular board, that combination plus a queen will be able to mate here; but I'm looking for more interesting combinations.
So, which piece combinations will be able to mate in this scenario?

In fact K+R+R can force checkmate against K on an open board.
First move both Rooks away from the King and to different rows and columns.
Then check the King with one Rook, say on a row.
Whichever side the King goes, move the other Rook to limit it to a single row.
Now the Rooks, moving only horizontally,
can limit the defending King to just four squares on that row,
with enough spare moves for the attacking King to approach:
[Title "RR keep K boxed in"]
[FEN "R7/5k2/2R5/8/8/8/8/K7 w - - 0 0"]

1. Rh8 Kg7 2. Rch6 Kf7 3. Kb2 Ke7 4. Rc8 Kd7 5. Rhc6 Ke7 6. Kc3 Kf7 7. Rh8

Once the King has joined the fray, mate can soon follow.  For example:
[Title "KRR mate K on infinite board"]
[FEN "7R/5k2/2R5/8/3K4/8/8/8 w - - 0 0"]

1. Ke5 Kg7 (1... Ke7 2. Rc7#) 2. Rch6 Kf7 3. Kd6 Kg7 4. Kd5 Kf7
5. Ke5 Kg7 (5... Ke7 6. R6h7#) 6. Kf5 Kf7 7. R6h7#


What is the 'combustion point' of a game? This was in an upvoted answer Saw an answer and it had been upvoted.
Person answering had a large rep on stack.

The term used that was not explained is:
'Combustion Point' (of a game)

My question is just what does 'combustion point' of a game mean?

Intuitively to a native speaker it would seem to mean something major like a disaster happened.  That does not seem to fit as it was applied to all games around move 26 per the OP it answered.

The question you mention is here: In ChessBase 12, when viewing an Opening Tree, why do all the games always stop near move 26?

Personally, I think it is just a general English statement he used to describe the middle, and most heated analytically, part of the game based on the context. I doubt anyone else would repeat it.

Frankly, if I downvoted a lot, I would probably have downvoted that answer since it does not really begin to answer the question. The real answer is either the user was doing something wrong, and should have been shown how to do it (probably not), or simply that was the way it was in the code because that is where they arbitrarily cut off the opening, and cannot be changed (probably).

P.S. If I were to ever describe a part of a chess game as such, it would be where everything came to a head, and the tactics started to fly.


Black's reply against anti-Grünfeld (3.d5) This is not the most famous anti-Grünfeld out there, but the move 3. d5 is a bit unconfortable for a Grünfeld player, at least for me.

Main moves are 3...Bg7 and 3...c6 challenging the d5 pawn right away. But I don't see a clear follow-up in either case.
What would you recommand considering I'm not a King's indian player ?

rnbqkb1r/pppppp1p/5np1/3P4/2P5/8/PP2PPPP/RNBQKBNR b KQkq - 0 1

In Volume 1 of his high-quality series on the Grünfeld for black, GM Avrukh recommends 3....b5!?, "playing in the spirit of the Benko Gambit". On page 6 of the PDF excerpt, you can find his analysis.

However, this may not be to everyone's taste. Instead, he also gives the line 3....c6 4.Nc3 cxd5 5.cxd5 d6 6.e4 Bg7 etc... "with equal chances". To me, this seems a good way to play: black has several ways to develop his pieces on the queen side and to create counterplay (e.g. Nbd7-c5, e6) and it is not necessary to memorize any complicated lines.

With 3.d5 white indeed avoids any Grünfeld structures, but it is relatively harmless and black can develop quite harmoniously.

      [StartPly "5"]

      [FEN ""]
      1.d4 Nf6 2.c4 g6 3.d5 c6 (3...b5) 4.Nc3 cxd5 5.cxd5 d6 6.e4 Bg7 7.Nf3 O-O 8.Be2 Nbd7 9.Be3 Nc5 10.Nd2 e6


Tips on how to beat a computer? What strategy should I use to win a chess game against a chess computer?

The engine is able to make decisions on an about 3 moves deep search graph.

Please do not say check every move in the next 4 moves...

There are several important points to know when playing a computer:

They will certainly outplay you in sharp positions, and they make nonsense moves in closed positions that involve positional play.
They have an horizon, that is, a moment where they cannot see any further.
They are very, very greedy. A pawn is a pawn they say, and the computer certainly likes material.

Knowing these, a human can try to capitalize by closing the position, simplifying and drying it until the computer has almost no tactical base, and simply makes useless moves. If the human manages to make the computer blunder (because of its horizon it cannot calculate further, but the human clearly sees that his positional advantage will grant him the win) or develops a (positional) plan that simply destroys the computer's position strategically, he most certainly will own the game.

Some famous examples are provided by the top GM Hikaru Nakamura. Here against Rybka you can see how he benefits from the fact that Rybka's programming does not allow it to give a draw when it's up in material (it was two exchanges up and about to arrive to the 50 move rule), and thus blunders several pawns trying to push the game and loses. Here you may look for more information on the match Nakamura (2770 ish) - Stockfish (3300 ish), where the GM had many great closed positions that seemed to end inevitably in a draw, but pushed too hard for the win and ended up losing.


Database program for statistics about mistakes I wonder if there is an application that will help with statistics for my own games. Of course - there are applications (eg. Scid, Chessbase) that allow to make some statistics out of database - but it mostly applies to openings. What I would like is to:
- import my games into the app
- run some kind of analysis (with more or less filters)
- get nicely presented statistical output by category

Sample scenario would be - I put all my standard games from 2016, and I want them to be scanned. After that I get report like:
- 40% lost because of tactical blunders
- 90% of draws were when playing black
- in 20% of won games I've reached endgame

It could be in some way done manually - so I could actually annotate the game with simple tags like: 'pawn endgame', 'slav opening' or 'tactical blunder' and put comments of my own or after I've analysed the game with the coach.

My question is - does this kind of application even exist?

I've built a web tool (https://www.chessinsights.org/) that you can use to upload your games, filter them, and find mistakes you made. The tool is free and open-source.

I'm currently working hard on adding features. If there's something you really want added, just let me know, and I can work on it.


Looking for an opening where stockfish puts out a queen early I am by no means a chess person (like 1200 haha). I am designing a computer science challenge where the player has to find a bug in my chess program to beat stockfish in a game of chess. The bug is that en passant is incorrectly programmed.
| | |
|Q|P|

In the above diagram, Q is a black queen, and P is a white pawn.
Imagine a position where our pawn is next to an enemy piece, like a queen. The program forgets to check that the piece it is trying to en-passant is a pawn.
This allows it to capture the enemy queen, like so:
|P| |
|X| |

(X being the position of the queen, that was "captured")
So I am looking for an opening that can draw the enemy queen out in this fashion. It doesn't have to be a particularly strong opening, since we will gain 9 pts advantage from taking the queen.
Does an opening like this exist, where the white player is able to get one of their pawns adjacent to the black queen?

If you can en passant any enemy piece and the engine doesn't know about it, you don't need to trick Stockfish into bringing its queen out early. You can play almost any way you want and let the game come to you eventually.
I guess a quick example can come from the Alekhine Defence. After 1.e4 Nf6 2.e5 Nd5, if I understood correctly you can put yourself a piece up with 3.exd6 e.p


Longest series of mutual "!" moves Normally I'd pester the/a computer chess forum, but I couldn't register yet...

On the Matplus chess forum, the following construction task came up.

Both White and Black are on the brink of losing because the position is so sharp. Both players have only one way to draw the game. However, the seqeunce falls under th Nunn convention-each move is the only one that doesn't lose, but it has at least one legal alternative. They are denoted as “!” moves. What is the longest sequence of mutual "!" moves?

Here is an illustrating example:

[FEN "2K5/8/7k/6N1/3q1N2/8/8/8 w - - 0 1"]

1. Nf7+ Kh7 2. Ng5+ Kh6 3. Nf7+

Nalimov confirms that 1.Sf7+! Kh7 2.Sg5+! Kh6! is the only way to draw (by repetition), but since Kh7 is also an only legal move, this position is invalid.

I don't have Nunns "Secrets" series at hand, where surely some examples can be found. Neither can  Imine a database for this question. Maybe you can?

The example below comes from Guy Haworth's Chess Endgame Records.

The annotations, as explained by Guy Haworth, are as follows:

% the only move available
! the only value-preserving move available (i.e., for a White move, the only winning move, and, for a Black move, the only drawing move, all others losing)
''' the only move which does not allow a repetition or otherwise waste time
''  the unique optimal move selected by the defined strategy
' an optimal but not unique optimal move

The other notation used is as follows (this is copied from Guy Haworth's book):

Metrics:
DTM Depth To Mate

Miscellaneous notation:
AUMS Absolutely Unique Move Sequence

[White "KR"]
[Black "KNP"]
[Result "1-0"]
[Date "2013.11.24"]
[Event "5m, 2-3m, KRKNP, GBR 0103.01, longest-known decisive AUMS: SV+M+/SUm"]
[Annotator "Haworth, Guy"]
[FEN "8/8/7p/7n/k7/8/2K5/3R4 w - - 0 1"]

1. Rd4+! {dtc/m/z = -26/-49/-17m} Ka3'' 2. Kd3! Kb3'' 3. Rd6! Kb4'' 4. Kd4! Nf4'' 5. Rb6+! Ka5'' 6. Rf6! Ne2+'' 7. Kc4! Ng3'' 8. Rg6! Ne4'' 9. Kd4! Nd2'' 10. Rg2! Nf3+'' 11. Kc5! Ka6'' 12. Rg6+! Kb7'' 13. Kd5! h5'' 14. Rh6! h4'' 15. Rf6! Ne1'' 16. Rf1! Nc2'' 17. Rb1+! Ka6'' 18. Rb2! Ne1'' 19. Ke4! h3'' 20. Rb1! Nc2' 21. Kd3! Na3'' 22. Ra1! h2' 23. Rxa3+! {KRKP: dtc/m/z = -3/-15/-3m} {Nalimov and Lomonosov DTM EGTs} *

Each of the first 35 plies, from White's 1st to White's 18th move, is the unique best for the player. What move is best for Black on their 18th turn depends on the criterion applied. Black's 18th move here, 18 ... Ne1, is the unique move which enables Black to maximise the number of successive White turns at which White has only one winning option. However, if Black is to maximise the number of future turns (i.e. maximise DTM), Ne1 is not best for Black: it loses for Black in 20; best is 18 ... Ne3+ (loses in 32) 19 Kc6 (best; wins in 32; Kc5 wins in 34).


Why do children move so quickly? I played a game against a 6 years old child where I launched a strong attack against the poor child:
[fen ""]
[white "Me"]
[Black "6 years old child"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4.Nxd4 Be7 5.c4 Qc7 6.Be2 a6 7.O-O Nf6 8.f3 Bc5 9.Be3 Qb6 10.Nc3 Nc6 11. Na4 Qa7(11...Bxd4 12.Nxb6 Bxe3+ 13.Kh1 Bxb6)  12. Nxc5 Qxc5 13. Nf5 Qf8 14. Nd6+ Kd8 15. Bb6+ Ke7 16.Bc5 Qg8 17.Nxc8+ Ke8 18.Nd6+ Kd8 19. Bb6+ Ke7 20. Nxb7 Qb8 21.Bc5+ Ke8 22. Nd6+ Ke7 23. f4 Kf8 24. e5 Ne8 25.Nf5+ Kg8 26.Ne7+ Nxe7 27.Bxe7 Qc7 28.Rf3 g6 29.Rd3 Ra7 30.Qa4 Qb6+ 31.c5 Qxb2 32.Re1 Qb7 33.Bf3 Qc7 34.Red1 Kg7 35.Rxd7 Qb8 36.Rd8 Qb5 37.Qxb5 axb5 38.Bf6+ Nxf6 39.exf6+ Kxf6 40.Rxh8 Rc7 41.c6 Ke7 42.Rhd8 Kf6 43.R1d7 Rxc6 44.Bxc6 h5 45.Rf8 Kf5 46.Rdxf7+ Kg4 47. Rg7 Kh4 48.g3+ Kg4 49.Rxg6+ Kh3 50.Bg2++

He played strange moves in a few seconds in the opening, e.g. as 5...Qc7 or more concretely 11...Qa7 missing the exchange of 3 pieces for a queen (which Stockfish says is good for black) much better than the position where black finishes after 13. Nf5. He also moved his bishop twice in the opening, his queen twice... all this with his clock over 1 hour and 30 minutes in a standard 90'+30'' game.
Once he lost a piece he spent some minutes to play his king's moves after the checks with only two or three possible moves. It seems that he thought more about it when defending himself, but when I checkmated him his clock was on 1 hour 12 minutes for a 90'+30'' game.
Why do children move so quickly in standard games, specially in the openings?
In the tournament I am playing half of the players are children and after one hour and a half all children have finished their games and there are only adults playing.
I know many children play forced by their parents to attend chess after school and might find boring to play chess, but I am asking about childs that like the game itself. I assume once a child joins a chess tournament it means he or she doesn't find boring to play a chess game. I am asking why children that like the game and play tournament games frequently don't spend minutes in tricky moves as adults do. Why don't they use their time?

The answer is very simple. A 6 year old child does not have an adult brain. It has the very immature, underdeveloped brain of a 6 year old. It has a short attention span and struggles to sit still for 5 minutes let alone spend 5 minutes on just one move.
A few years ago I was chief arbiter for three junior tournaments held at the same time. I got one of the coaches who is also a qualified arbiter to help me. Obviously he wasn't allowed to help his players even in the breaks between rounds.
Instead before every round he stood up and made the same speech basically begging the kids to take more time over their moves. The time control was something like 25+5 and yet most games were over in less than 10 minutes with the players thoughtlessly blitzing out moves.
As he explained to me, kids tend to move too fast in games which are just friendly, relaxed games. But when it is a competition and clocks are involved their brains interpret it as some kind of race and they have even less control of their time management. Adrenaline takes over and calm calculation flies out of the window.


Online Resource for Opening Plans I have been searching for a while for an online (preferably free) resource for opening plans. Up till now my study of openings has consisted of looking at popular lines and some master games. Is there any website or e-book that you are aware of that focuses on the plans behind each opening?

The St. Louis Chess Club has a YouTube page full of video lectures, many of which delve into the opening ideas.  iChess.net also has such videos, for example: "The Ideas Behind the Chess Openings! IM Vlaeri Lilov (Webinar Replay)"

Then there are some wiki pages that actually have decent explanation of some openings.


Threatening the Queen in the bishop with Bg5 I have long been playing games in which I can develop my bishop to g5 like in the following positions:

The truth is I have trouble deciding if such moves are useful. In the diagrams, what pushed me to playing such move is specially my pawns on e5. But maybe come to think of it, that is not much of a compelling factor. Is there anyway to reliably determine when this move would be worth it?

When your pawns are on the dark squares, as in your examples, it is often "Positionally" desirable to exchange your dark squared Bishop so responses like ...Be7? would leave Black weak on the dark squares.

But in chess you must be concrete, which means you must calculate.  What if Black plays ...f6 which is often a thematic assault on your pawn chain -- now with tempo.

Look over grandmaster games and learn from what they do.


How to deal with the Cochrane Gambit [fen ""]

 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7 ?!

I'm pretty sure the Cochrane Gambit isn't correct. However, I find it difficult to defend against, as some "natural" moves don't seem to work. Can you give some advice how to deal with it? Further, I guess it might be a surprise weapon in a blitz game, so have some of you tried it out?

The Cochrane Gambit sacrifies his Knight for a few things:

He sacrifies the Knight for 2 pawns
After Kxf7, Black loses castling rights and is dangerously in the
center.
Blacks King-side is basically destroyed with only the g and h pawns
and it is not easy to find the best square for the Black King.
Usually White will check with the Bishop with Bf4 and if Black
blocks with Be3, then White should just exchange bishops and bring
the black king further into the center making it harder to castle
manually.
White wants to build a strong pawn center by pushing his pawns
especially on the king-side. For example, White wants to develop his strong pawn center by pushing d4, f4, e5 and further fortify his strength in the center with Nc3 and Bd3 or Bf4.

With the above said, I think Black's goal should be to neutralize White's strong pawn center. In the Kramnik-Topalov game, I think Kramnik made a good move with 5...c5 to challenge the d4 square. From here White has to chose between playing 6. f4 followed by 7. e5 trying to break Blacks position, but in this case White's Bishop on c1 is not playing. Topalov instead played 6. Bf4+ to not lose any tempo and 6...Be6 is basically forced and after the exchange of Bishops, Black's King is more brought deeper into the center.

Some popular replies for Black after 5. Nxf7 Kxf7 6. d4 could be:

c5
g6
c6
Qe8
Be7

Lets look at the c5 first:

[FEN ""]
1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7 Kxf7 5. d4 c5

White's most popular reply is 6. dxc5, followed by 6...Qa5+ 7. Nc3 Qxc5 8. Be3 and White maintains his the initiative.

Now onto c6:

[FEN ""]
1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7 Kxf7 5. d4 Be7 6. Nc3 c6

Usually with 5...Be7, Black wants to try to castle manually and White continues development with 6. Nc3. After 6...Re8, Black is in trouble after Bf4+, so instead 6...c6 with the plan of playing d5 later. After 7...d5, it might continue 8. exd5 cxd5 9. Nxd5 Nxd5 10. Qh5+ Kf8 11. Bxd5 Qe8. I would say White is better here because his Black's King is still weak and he has 3 pawns for the Knight

Regarding g6:

[FEN ""]
1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7 Kxf7 5. d4 g6

g6 might be Black's most popular reply. After 6. Nc3 Kg7 7. Be2 d5 8. e5 Ne4 9. Nxe4 dxe4 10. O-O Nc6 11. Be3 h5 12. f3 exf3 13. Rxf3 Be6 14. c4. Even with this, White still has an advantage.

Last, Qe8:

[FEN ""]
1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7 Kxf7 5. d4 Qe8

Here Black threatens e4. It usually continues: 6. Nc3 g6 7. Bd3 Kg7 8. O-O Nc6 9. Bd3 Nc6 10. Be3 Nb4. White may panic here because of the attack on the White-Squared Bishop, but instead of panicking, White should play 11. h3 Nxd3 12. Qxd3 Rg8. Black wants to play Kh8, so White should go for the attack with e5. Black is very disorganized and in a positional disadvantage.

In a nutshell, I believe breaking White's center as Kramnik did is the best possible way to either draw or defeat the Cochrane Gambit


Plans in the Scandinavian Defence I'm playing the Scandinavian Defence with 3...Qd8 a lot and I really like that opening. But I can't seem to find the right plan. I just develop my pieces towards the center (I don't fianchetto my bishop on g7) and then hope my opponent blunders. Could you please tell me on what I can improve? I'm a 1200 FIDE rated player.

I have already searched the web but the only thing I came up with, was that Scandinavian Defence is considered bad at high level.

I also saw some master games but that doesn't really help as they all play 3...Qa5.

If you really must, because your friend bet a wager that he can beat you as black in this position, here are the imbalances, concrete and possible, that you must look out for (as white):
[FEN ""]

1.e4 d5 2. exd5 Qxd5 3. Nc3 Qd8

Black's open d-file
Active LSB
Kingside pawn majority

Still, this is not without its weaknesses:

A delay in development. White can safely continue with d4, Be3, Qd2, O-O-O.

Black's reduced control of the squares on the e-file. Castle long and prompt to push his f-pawn somehow, followed by a minority attack g2-g4 (or g2-g4-g5).

Black's reduced control of the squares on the c-file. If black castles long, or the situation somehow else warrants it, break open the c-file, create an outpost on the c4-c5 square, and move a knight, bishop, or rook to this square where b7-b6 or b7-b5 has to happen. Now you'll have a new, but weakened structure to attack.
Black will play to nullify white's knights with ...Bg4 (if Nf3), ...e6, ...Bc5, Ne7, and O-O, finally obtaining a solid position. If white castles short, black can launch a minority attack, creating holes which his knights can then infiltrate. He can place pressure on the d-pawn by restricting its advance, playing c7-c6, ...Rd8, and ...Nd5. If white plays c4, then the d-pawn has become weakened and serves as a target.


Does ...Rxe3+ work for Black? In the position below, does ...Rxe3+ sacrifice work for Black?
I need concrete lines, that prove your claims, I can not satisfy myself with some rough evaluation.

Thank you. Regards.

[Title "Black to move"]
[StartFlipped "0"]
[fen "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

1...Rxe3+

This looks like a 'no engines' question, otherwise ALNS would have just used Stockfish. Be afraid, B-player analysis is happening!

[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

1...Rxe3 2.Kxe3 Re8+ 3.Kd2 Bf4

[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

1...Rxe3 2.Kxe3 Re8+ 3.Ne4 Rxe4+ 4.dxe4 Qxe4+ 5.Kd2 Bf4+ 6.Kc3 Nd5+ 7.Kb3 Qb4#

[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

1... Rxe3 2.Kxe3 Re8+ 3.Ne4 Rxe4+ 4.Kd2 Bf4+ 5.Kc3 Nd5+ 6.Kb3 Qxf2 7.dxe4 Qb6+ 8.Kc4 Ne3+

[Title "White survives, sort of"]
[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

1... Rxe3 2.Kxe3 Re8+ 3.Ne4 Rxe4+ 4.Kd2 Bf4+ 5.Kc3 Nd5+ 6.Kb3 Qxf2 7.a3 Qb6+ 8.Ka2 Be5 9.c3 Nxc3+ 10.bxc3 Bxc3 11.Rg2 Qe6+ 12.Qb3 Re2+ 13.Rxe2 Qxe2+ 14.Kb1 Qxd3+ {After this Black is able to trade the pieces and have a deadly pawn majority on both sides of the board, and an extra piece. Further play was very computery so I didn't post it.}

[Title "Stockfish calls it a win"]
[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

 1... Rxe3+ 2.Kxe3 Re8+ 3.Ne4 Rxe4+ 4.Kd2 Nd5 {Here's the killer. The knight closes the luft on c3} 5.dxe4 Qxf2+ 6.Qe2 (6.Kc1 Bf4+ 7.Kb1 Nc3+ 8.bxc3 Qb6#) Bf4+ {Now Black strips the Queen's defender} 7.Kd1 Ne3+ 8.Kd2 Nxg4+ 9.Kc3 Qxe2 10.Rge1 Bd2+ 11.Kd4 Qf2+ 12.Kd5 c6+ 13.Kc4 Ne5+ 14.Kb3 Qb6+ 15.Ka3 Qb4#