Why are world-class engines playing like this? I was reading about the Lc0 engine and its evolution. Then took a glimpse at the games between Lc0 and the notorious Stockfish. I am not a professional or anything remotely close, but this particular game seems very odd to me. According to chess.com:

  The Lc0 engine got off to a fast start in the bonus games, beating the reigning Computer Chess Champion Stockfish despite Lc0 starting down a pawn in the odds-chess position. In typical Leela style, the engine underpromoted to a rook to drive the win home.

[FEN "CCCC 1: Rapid Rumble (15|5) Bonus Games"]
[Date "2018.10.03"]
[White "Lc0 17.11089"]
[Black "Stockfish 220818"]
[Time "09:33:10"]
[TimeControl "900+5"]

1. f4 Nh6 2. f5 Nxf5 3. Nf3 Nh6 4. Ng1 Ng8 5. e4 e6 6. Nc3 d5 7. d4 Bb4 8. e5
Qh4+ 9. g3 Qd8 10. a3 Bf8 11. Be3 Ne7 12. Nf3 Nf5 13. Bg5 Be7 14. Bxe7 Nxe7 15.
Bd3 h6 16. b4 b6 17. O-O O-O 18. Ne2 c6 19. a4 c5 20. c3 Nbc6 21. Qd2 Bd7 22.
Rae1 Rc8 23. b5 Na5 24. Nf4 cxd4 25. cxd4 Qc7 26. Rc1 Qd8 27. Rxc8 Qxc8 28. Nh5
Nc4 29. Qf4 Ng6 30. Nf6+ Kh8 31. Qc1 Na5 32. Qd2 Nc4 33. Qc1 Na5 34. Bxg6 Qxc1
35. Rxc1 gxf6 36. Bh5 Nc4 37. exf6 Kg8 38. Ne5 Nxe5 39. dxe5 Rc8 40. Rxc8+ Bxc8
41. Be2 d4 42. Bf3 h5 43. Bxh5 Bb7 44. Kf2 Be4 45. Ke1 d3 46. Kd2 Kf8 47. Ke3
Bh7 48. Bd1 Ke8 49. g4 Kd8 50. Kd2 Ke8 51. Ke3 Kf8 52. Kf3 Ke8 53. Kf2 Kd7 54.
Ke3 Kc7 55. h4 Kc8 56. h5 Kd7 57. Kf3 Ke8 58. Kf2 Kf8 59. Ke3 Kg8 60. Kf4 Kh8
61. Kf3 Bg8 62. Ke4 Bh7+ 63. Kf4 Kg8 64. Ke3 Kf8 65. Kf2 Be4 66. Ke3 Bh7 67. Bb3
Kg8 68. Bc4 d2 69. Kxd2 Be4 70. Be2 Bb7 71. g5 Be4 72. Bd1 Kh8 73. Kc3 Kg8 74.
Be2 Bf5 75. Kd2 Bb1 76. Bd1 Kf8 77. Kc3 Ke8 78. Kb2 Bh7 79. Kc3 Be4 80. Kd2 Bf5
81. Ke3 Bb1 82. Kf3 Kf8 83. Ke3 Ke8 84. Kd4 Kf8 85. Kc3 Bh7 86. Be2 Kg8 87. Bg4
Be4 88. Bd1 Kh8 89. Kd2 Bh7 90. Bg4 Kg8 91. Bd1 Kf8 92. Bb3 Ke8 93. Bc4 Kd7 94.
Be2 Ke8 95. Kc3 Kf8 96. Bd1 Bb1 97. Bg4 Be4 98. Kd2 Kg8 99. g6 fxg6 100. Bxe6+
Kf8 101. h6 g5 102. Ke3 Bg6 103. Bd5 g4 104. Kf4 g3 105. Kxg3 Ke8 106. e6 Kd8
107. Kf4 a6 108. bxa6 Be8 109. a7 Kc7 110. a8=Q Kd6 111. h7 Kc5 112. h8=R Bd7
113. Ke5 Kb4 114. Rh3 Bxa4 115. Kd4 Bd1 116. Bc6 Bb3 117. f7 b5 118. f8=Q# (118.
f8=B#) 1-0

Ok, I can understand that Lc0 gives a pawn in advance —maybe to show off its superiority, but the rest of the game is full of unbelievably stupid moves. And ironically, those amateur moves are coming from both sides. For example, even for someone like me, 9. g3 Qd8 is hard to believe.

I also can understand that in rapid games, stupid moves are likely to happen. But these are chess engines who can find almost perfect moves in a fraction of second (well, according to my personal experience with Stockfish). So time limit cannot be such a heavy barrier. Then why are they playing dumb like this? Is it intentional or something?

Basically, the first four moves were implemented to start a game without the f2 pawn, i.e., with an imposed handicap. The game starts at move 5 with a French Defense set-up for Black. I'm surprised that Lc0 can win against Stockfish with a pawn down. I would probably have chosen to play e5 than e6, with the idea to install a Bishop in c5 and try to take advantage of the open g1-a7 diagonal.

I was also intrigued by some of the positions and their seemingly dumb moves, but some of them are not that dumb!

You mentioned a first puzzling moment after 9.g3

Lc0 has a pawn down and Stockfish plays to win with Qd8! By taking in h1 Stockfish could be even worst. Then, we may question the Qd8-h4-d8 sequence that has the advantage of weakening the kingside but loses two tempi. Reacting by c5 instead of Qh4 was probably more natural.

[FEN "rnb1k1nr/ppp2ppp/4p3/3pP3/1b1P3q/2N3P1/PPP4P/R1BQKBNR b KQkq - 0 1"]
[title "Position after 9. g3"]

9... Qd8! {was played and Lc0 has a pawn down and Stockfish plays to win with Qd8!} (9... Qe4? {is the obvious move but} 10.Kf2 Qxh1 (10...Bxc3 11.bxc3 Qxh1 12.h3!! is a transposition) 11.h3!! 11...Bxc3 12.bxc3 Qe4 13.Nf3! {White can maybe play for a win here because I don't see how the Queen escapes!} (13.Bd3 Qh1 14.Bf1=))

The second one is after the massive exchanges 41.Be2

White has winning chances in this endgame and Stockfish tries to find some counterplay by playing 41... d4. Assume Black waits and plays Bb7-Ba8 without playing d4. Then, the winning plan for White is to bring the King to h5 to collect the h6 pawn.

[FEN "2b3k1/p4p2/1p2pP1p/1P1pP2B/P7/6P1/7P/6K1 w - - 0 1"]
[title "Position after 40... Bxc8"]

1.Be2! d4 (1...Bb7 2. Kf2 Ba8 3.Kf3 Bb7 4.Kg4 Ba8 5.Kh5 Kh7 6.Bd3 Kg8 7.Kxh6+-)

Update. There are still some positions where like @polfosol I can't understand Lc0 moves! For instance, after 78... Bh7, the move 79.Kc3 seems indeed quite "dumb"! After 79.Bc2! the win is very easy (at least for a human ;-).

[FEN "4k3/p4p1b/1p2pP2/1P2P1PP/P7/8/1K6/3B4 b - - 0 1"]
[title "Position after 78... Bh7"]


After 1. d4 d5 2. c4 e6, should White play 3. cxd5? I play the Exchange variation as White when Black plays 2...e6 against the Queen's Gambit. Should I play 3. cxd5 to avoid the transpoition to the Slav 3. Nc3 (hoping for 3...Nf6 4. cxd5) c6!?

[FEN ""]

1. d4 d5 2. c4 e6 3. cxd5!? (3. Nc3 c6!?)

After 3.cxd5 exd5 4.Nc3, if black plays 4....Nf6 or 4....Be7, then white indeed succesfully transposed to the mainlines of the QGD and avoided any transpositions to the Slav.

Black's best reply is probably 4....c6, after which white has 3 good options: 5.Nf3, 5.Bf4 and 5.Qc2.

After 5.Nf3 black can play 5....Bd6 or 5....Bf5.
After 5.Bf4 black's best moves also are 5....Bd6 or 5....Bf5. (Black has an extra tempo compared to 3.Nc3 Be7 4.cxd5 exd5 5.Bf4 c6 6.e3 Bd6, as in Wojtaszek - Kraemer)
After 5.Qc2, both 5....Bd6 and 5....g6 (with idea Bf5) seem good moves for black.

In all variations, black has a good version of the QGD, as white cannot prevent him from developing his bishop to f5.

It seems that after 3.cxd5 black equalizes rather easily and that 3.Nc3 or 3.Nf3 are much more principle moves.
However, 3.cxd5 cannot be called a mistake. If the Carlsbad structure suits your playing style, then it is worth a try.

  [StartPly "4"]

  [FEN ""]
  1.d4 d5 2.c4 e6 3.cxd5 (3.Nc3 Be7 4.cxd5 exd5 5.Bf4 c6 6.e3 Bd6) exd5 4.Nc3 c6 (4...Nf6)(4...Be7) 5.Qc2 (5.Nf3 Bd6 (5...Bf5)) (5.Bf4 Bd6 (5...Bf5)) 5...Bd6 (5...g6)


Why does FIDE still use Elo? I've been impressed with the way the Glicko rating system works. In particular:

more games played recently cause your rating to stabilize
fewer games played recently cause your rating to fluctuate until you get several recent games under your belt

USCF modified their system to be similar a few years back (where there is a sliding scale to amplify or dampen the rating change for a given match), and now that Glickman (the inventor of Glicko) is on the rating board for the USCF, I imagine they'll eventually adopt an even more flexible system, like his own.

Is there a reason (other than being resistant to change, or that they just haven't gotten around to it yet) that FIDE doesn't adopt a more accurate rating system?

It is not proven that Glicko is more accurate.  Glicko just solves the problem a different way, with a different emphasis.  Consider that all these systems abstract a human mind to a 4 digit number.

There's a lot of politics in ratings; it's a touchy subject.  If FIDE were to adopt it, they'd produce a new top-100 list, and a lot of GMs would likely be upset.

The ELO system is very easy to understand; transparency is important.  More complex systems have immediate disadvantages.


How do GMs “play the man, not the board”? How do GMs "play the man, not the board" as some books say? Would that work for club level players or could they use other methods? Prepared variations? Trash talk?
What are the ways one can play the man but not the board that are they legal under FIDE rules and would not be called annoying the opponent or the like?

As you mentioned, playing the man can mean several different things, but before I answer I want to say that no one can become a better player by only playing the man - objectivity is the number 1 priority.

Many top-level GMs do play the man and the most notable example I can give is the Kasparov-Kramnik match in 2000. Kramnik knew that Kasparov disliked queenless middlegames, so he put the Berlin into his opening arsenal. Kramnik also played d4 in his match because Kasparov was known to be a deadly Najdorf player (it should be noted that Kramnik did play e4 at that time). Another example that I can think of is a younger player taking advantage of an older player's fatigue and grinding the position down for hours. These are the main ways that GMs play the man as far as I know.


Capturing the king in a blitz game In a blitz game, when my king is checked, I make an illegal move that checkmated the opponent and pressed the clock. Then my opponent captured my king and claimed victory. Capturing the king is not a legal move. Who wins?

This is a good question indeed and a somewhat bizarre situation, which is not fully covered by the Laws. As you mention the opponent has completed an illegal move and you claim that. The relevant parts of the Laws are articles A.4.2., B.2 and 7.5.5.

The easy case is if your opponent has made an illegal move (that has been claimed) before. In that case they lose the game.

If this is a first illegal move your opponent has made in this game, however, then the arbiter will give you one minute extra time, the opponent's last move is taken back and they have to play any other move that is legal. This is where things become complicated. Your opponent has been checkmated and thus there is no legal move they can play. According to article 5.1.1 they should lose the game but only if the move producing the checkmate was legal, which it was not. Therefore, since your opponent cannot make any legal move, the game cannot continue but it has not finished and there is no result. Quite bizarre indeed.

The following is a somewhat bizarre solution to a bizarre situation. If the opponent is satisfied with a draw they could ask the arbiter to watch the next move and then make a move that leaves both kings in check. Then the arbiter will declare the game drawn according to article A.4.4..

If the opponent does not want a draw then the only solution that satisfies the Laws is that both players agree to correct the illegal move that caused the checkmate. This is allowed by article A.4.2. If they don't agree the Laws do not tell you what to do. In such situation, I, as an arbiter, would rule to correct that move nonetheless without penalizing the player who made it (i.e. you) since it was the opponent's responsibility to make a claim.

Current Laws of Chess are here.


Deep Blue vs Kasparov - Aftermath Evaluating 200M positions per second and having a search tree of 20+ moves might not be enough to beat a World Champion if a computer searches in the wrong direction or if it's evaluating positions a human opponent would never consider (either by instinct and/or reasoning). Coding tactics is easy, coding strategy is hard.

Was Deep Blue human assisted when it beat Kasparov in 1997? Is there any evidence about that?

Can a commercial software chess game running on a "common machine" beat a chess master nowadays?

Game Over: Kasparov and the Machine is a decent enough documentary on the subject. The coverage does kind of imply that Kasparov was grasping at straws a bit. Like a typical World championship match there was a lot of behind the scenes tactics going on from both sides.

My feeling is that you only have to look at the ascent of Anand and other chess players who rely heavily on computers in their training and analysis to realise that, at the time of this match, there was a paradigm shift from human to computer as the dominant chess player.

Addendum:

There's a interesting tidbit in Nate Silver's “The Signal and the Noise: Why So Many Predictions Fail—But Some Don’t.” In it he describes an interview with one of the engineers who worked on Deep Blue:

  Nevertheless, there were some bugs in Deep Blue’s inventory: not many,
  but a few. Toward the end of my interview with him, [Murray] Campbell
  somewhat mischievously referred to an incident that had occurred
  toward the end of the first game in their 1997 match with Kasparov. “A
  bug occurred in the game and it may have made Kasparov misunderstand
  the capabilities of Deep Blue,” Campbell told me. “He didn’t come up
  with the theory that the move it played was a bug.” The bug had arisen
  on the forty-fourth move of their first game against Kasparov; unable
  to select a move, the program had defaulted to a last-resort fail-safe
  in which it picked a play completely at random. The bug had been
  inconsequential, coming late in the game in a position that had
  already been lost; Campbell and team repaired it the next day. “We had
  seen it once before, in a test game played earlier in 1997, and
  thought that it was fixed,” he told me. “Unfortunately there was one
  case that we had missed.” In fact, the bug was anything but
  unfortunate for Deep Blue: it was likely what allowed the computer to
  beat Kasparov. In the popular recounting of Kasparov’s match against
  Deep Blue, it was the second game in which his problems
  originated—when he had made the almost unprecedented error of
  forfeiting a position that he could probably have drawn. But what had
  inspired Kasparov to commit this mistake? His anxiety over Deep Blue’s
  forty-fourth move in the first game—the move in which the computer had
  moved its rook for no apparent purpose. Kasparov had concluded that
  the counterintuitive play must be a sign of superior intelligence. He
  had never considered that it was simply a bug.


Clarification in the book Logical Chess, Move by Move, by Chernev I am working through the book mentioned and in game 8 (Przepiorka vs Prokes) at move 4 ...P-B4, which is black moves pawn to C5.  The book states the following:  "This move is almost indispensable in Queen Pawn openings.  It is important not to play ...Kt-C6 first, as the bishop pawn must not be obstructed."  Could someone shed some light on the importance of ensuring the queen's bishop pawn is unobstructed?

Often black plays b6/Bb7/c5 to support an attack against the White d-pawn, and at times even Na6 to support c5. Obstructing the c-pawn slows down or prevents these kinds of maneuvers. Nc6 is an awkward placement of the knight on the queenside with d5/e6 being played by black, as it has no real good second move from c6 to get out of the c-pawns way, thus losing time, if black wants to follow up with ...c6 or ...c5. The move ...c5 is a "breaking" move that black wants in many openings, including the Caro-Kann, the French, etc., and not just d-pawn openings. A knight on c6 is generally speaking a 'good' knight when ...e5 and/or ...c5 has been played, i.e., king's pawn openings, The Sicilian Defense, etc.


Queen's Gambit Accepted with black trying to defend the c file pawn with 4. ... Bd7 In the following opening:

[FEN ""]
1. d4 d5 2. c4 dxc4 3. e3 b5 4. a4

There is a well-known trap if Black tries to defend the c file pawn with:

[FEN ""]
1. d4 d5 2. c4 dxc4 3. e3 b5 4. a4 c6

However I got the following played against me:

[FEN ""]
1. d4 d5 2. c4 dxc4 3. e3 b5 4. a4 Bd7

How should White respond?

[fen ""]

1.d4 d5 2.c4 dxc4 3.e3 b5? 4. a4! Bd7? 5.axb5! Bxb5 6.Bxc4! Bxc4 7.Qxa4+

and White gets back the bishop with the advantage ( no matter what Black plays Qxc4 is White's next move ).

Hopefully this answer helped.

Best regards.


Effective method to teach defense (I.E. opening as Black) to children Specifically, Black is disadvantaged by always being one move behind.  While being subject to this disadvantage, what is an effective method or exercise to teach children/beginners the following principles while opening as Black:

Control the center.
Protect (castle) the king.
Connect the rooks.
Rooks to the center file(s).

For instance, if I were to introduce the Caro-Kann Defense as a means to this end, would there be any of the above points that might be missed?  Or if not missed, maybe points that might be better conveyed if learning them from a different defense?

It seems that your question deviates from the the point that Black is at a disadvantage. Instead, you seem to mention opening principles that are color agnostic. Controlling the center, protecting the king, and developing pieces are the three key idea in the opening.

I wouldn't worry too much about teaching specifically attack and defense. These are actually higher-level concepts that are taught at a higher level.


Is the bishop pair and a pawn equivalent to knight and a rook? In theory, rook (5) + knight (3) = 8 points.

And bishop (3.25) + bishop (3.25) + pawn (1) = 7.5 points.

For example, do you think black is better in the following scenario or do you believe white can hold with good play?

[fen "1n2k2r/ppp1pppp/8/8/8/8/PPPPPPPP/2B1KB2 w - - 0 1"]

It's an oversimplification to think of the bishop pair to be worth 0.5 points on average. There are cramped positions where a bishop is barely better than a pawn. It's very difficult to generalize based on your question, it will vary greatly from position to position. But in case you're only interested in an "on average" answer, then the side with the rook has a slight edge.


Is there a reason for MC's second move? In this game, Magnus Carlsen made an unusual poor first move Nh3. Presumably, it was to throw off his opponent, especially since the game was under fast time controls, so that is understandable. But I cannot understand why he played another poor move after that. Why f4? Why not d4 or g3 (with their obvious benefits)? Is 1. Nh3 Nh6 so frequently used that he needs to make two poor moves in a row to make sure his opponent has no preparation? More concretely, is there any potential positional gain by f4? As far as I can tell, f4 only serves to expose the king and delay development of all the pieces...

[FEN ""]

1. Nh3 Nh6 2. f4 d5 3. Nf2 Ng4 4. e3 Nxf2 5. Kxf2 c5 6. b3 Nc6 7. Bb5 Bd7 8. Bb2 a6 9. Bd3 Qc7 10. Nc3 e6 11. Qh5 Be7 12. Rhf1 Bf6 13. Kg1 Nb4 14. Rac1 Nxa2 15. Rce1 Nb4 16. f5 e5 17. e4 c4 18. Nxd5 Nxd5 19. Bxc4 Nb4 20. c3 Nc6 21. Qxf7+ Kd8 22. Ba3 Be8 23. Qd5+ Qd7 24. Bd6 Be7 25. Bxe7+ Kxe7 26. Qc5+ Qd6 27. Qb6 Bd7 28. d4 Nd8 29. Qa5 Nc6 30. Qa2 Kd8 31. Rd1 Kc7 32. Qf2 Rad8 33. b4 Rhf8 34. b5 axb5 35. Bxb5 g6 36. f6 Kb8 37. Bc4 Bc8 38. Bd5 Be6 39. Bxe6 Qxe6 40. d5 Qd6 41. Ra1 Kc7 42. dxc6 Qxc6 43. Ra5 Kb8 44. Qa7+

2.f4 is a poor move, just like 1.Nh3 was. 1.Nh3 puts White at roughly -0.50; then, after 1...Nh6 White comes back to around 0.3. If Carlsen had played 2.d4, like you said, he would have maintained this evaluation. Instead, 2.f4 brings things down to -0.4ish.

A reason behind 2.f4 is to bring the knight back to f2, but it's still a bad move. As I mentioned in the previous question on this game, Carlsen was clearly just having fun in an online rapid game. There was no deep strategy involved. If he wanted to play some deceptive variation with the sole intention of winning, you would have seen something far more impressive than this from the world champion.

If you want to analyze Carlsen's games in order to learn from them, please take a look at ones he's played in serious super-GM tournaments. Trying to glean knowledge from an online game in the PRO league isn't worthwhile (especially when 1.Nh3 is the first move).


How do you play if both sides get a queen? Here, I've read through the famous Réti endgame study. However, there is a possibility that both sides can get a queen. For example, take a look at this variation.
[FEN "7K/8/k1P5/7p/8/8/8/8 w - - 0 1"]

1.Kg7 h4 2.Kf6 h3 3.Ke7 h2 4.c7 h1=Q 5.c8=Q+ *

I've consulted another Wikipedia page, entitled "Pawnless chess endgame", and it says "Queen versus queen: usually a draw, but the side to move first wins in 41.75% of the positions." You can also see the table from the "Tables" section, under the "Common pawnless endgames" subsection. It basically states the same thing. In queen vs. queen, the longest win is in  10 moves and the winning percentage is 42%.
I am really not very good at chess, but is the Wiki article totally correct? If it's correct, then, considering my 41.75 percent winning chance, how do I have to play in order to defeat my opponent if he/she and I both get a queen?

considering my 41.75 per cent winning chance, how do I have to play in order to defeat my opponent if he/she and I both get a queen?

First of all you need to understand what is meant by "41.75% winning chance". It does NOT mean that your chances of winning are 41.75%. What it means is that in 41.75% of the games considered the game ended in a win and in the other 58.25% it ended in a draw.
Before heading for such an endgame you should first calculate what the result will be because it is pretty hard and fast unless one side blunders.
Basically (provided no blunders) it is always a draw unless one of two conditions apply:

The side on move has a forced sequence of moves leading to checkmate
The side on move has a forced sequence of moves leading to win of the opponent's queen

The problem is that if the side on move is not in check then they usually have the possibility of an almost endless series of checks on the opponent's king.
Here black is in check and can force an immediate draw by blocking the check with the queen and simultaneously giving check with Qb7+.
However even if black played Kb6 there is no forced checkmate for white and provided black doesn't blunder (by putting the king on the a8-h1 diagonal, the back rank or the h file allowing a skewer check) there is no chance of losing the queen. So it is going to be a draw.


Is using a 2D magnetic board in tournament play legal? Is it okay to have a 2d magnetic chess set next to your score sheet? And as you play, you move along with the pieces. I like looking at a 2d board better because it's smaller and I'm used to playing on my computer. I look at the 2d board and then play on the 3d board. After I've made my move on the 3d board. THEN I move the pieces on the 2d board. Is there a rule against playing like this in tournament?

I'm pretty sure the rules of most serious tournaments prohibit the use of a second board for any reason, but I'm not sure if there are special provisions for people with disabilities and disadvantages.

As a player, I would be quite apprehensive towards playing someone who is using a second board, simply because it means I have to keep an eye out to ensure he is not cheating. I would certainly have a word with the arbiter if that situation were to occur.


Mysterious rook move in the Grunfeld [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1. c4 g6 2. d4 Nf6 3. Nc3 d5 4. Nf3 Bg7 5. cxd5 Nxd5 6. e4 Nxc3 7. bxc3 c5 8. Be3 Qa5 9. Qd2 Nc6 10. Rb1 a6 11. Rc1

In this line of the Grunfeld, White has played 10. Rb1 followed by 11. Rc1. Why? If White wants the rook on c1, why not just play 10. Rc1? What is the benefit of provoking 10...a6 first?

Peter Svidler explains this in his excellent video series and e-book on the Grünfeld (Premium access only).

The point is the initiative. This move discourages black from playing 11...cxd4, because that would lead to a very uncomfortable situation for black: After 12.cxd4 Qxd2+ 13.Kxd2 O-O 14.d5 Rd8 15.Ke1, there is no good square for the knight. 15...Na5 is now impossible, because the bishop can go to b6.

And this is the reason why Svidler follows Avrukh's recommendation to play 11...Bg4 in this case.

[ECO "D85"]
[Opening "Grünfeld Defense: Exchange Variation"]
[FEN ""]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Be3 c5 8. Nf3 Qa5 9. Qd2 Nc6 10. Rb1 a6 11. Rc1 cxd4 (11... Bg4 { Recommended by Avrukh and Svidler } 12. d5 Rd8) 12. cxd4 Qxd2+ 13. Kxd2 O-O 14. d5 Rd8 15. Ke1 Nb4 (15... Na7 { Best move according to Stockfish. Has never been played. })  (15... Ne5 16. Nxe5 Bxe5 17. f4 Bb2 18. Rc2 Ba3)(15... Na5?? 16. Bb6!) 16. Bd2 a5 17. a3 Na6 *


Open source Chess engines under MIT license? What are some of the open source Chess engines under the MIT license?

  The purpose of the search is to find a suitable strong engine to be used in our chess hardware/software product. Thanks.

Crafty
Arasan

I don't recommend Pulse or NG-Play in the other answer as they're no longer maintained. The three engines I cited are still very active.


Giving up a knight and bishop for castled rook and pawn The opening shown here is quite common. Is it generally a good or a bad idea to give up a kKnight and a bishop for the castled Rook and the f-pawn? In terms of their "standard" value, both pairs are generally considered as being worth 6 points.
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 e5 2.Nf3 Nf6 3.Bc4 Bc5 4.Ng5 O-O 5.Nxf7 Rxf7 6.Bxf7+ Kxf7

This whole sequence is bad for white.  The minor pieces are stronger at such an early stage of the game.  White has virtually no development, while black now has more development and tempo.  Almost any player should value 2 pieces over 1 rook.  Just continue developing instead of the overly optimistic Ng5.

This may be acceptable in the dilworth attack or Open Ruy Lopez where black sacrifices 2 pieces for a rook on f2


Is Whale Variation a successful opening? I am an early, intermediate in chess. I played the Whale Variation and won some games as White. But there is an issue when Black moves their knight to d4. I have a problem with it. Is the Whale Variation a proper opening to use?  I like to know your ideas about Whale Variation.

The Whale variation
[FEN ""]
1.e4 e5 2. c4

is quite an offbeat opening. It shares obvious similarities with the English opening, and it sometimes transposes, but it has some serious drawbacks. The obvious one is the gaping hole it leaves on d4. Another one is that it leads to very closed positions, which intermediate players usually do not fin comfortable. This leads to inaccurate plans and rushing, which because of the dubious setup from white, usually ends up favoring black. The main one is that white does not have a threat, allowing black to immediately seize the initiative with Nf6.
Let's address first the hole on d4. There are several setups to play around it, the most straightforward plan is to play d3, Be3, and Ne2. This overprotects the weakness and ensures better center control, but is awfully slow since Bc5 essentially blocks everything, and severely neglects king safety (white's not gonna castle anytime soon). Another setup is to kingside fianchetto, and another is with Be2. They all have big drawbacks, since essentially white is playing an English opening with a way too early e4 push. With somewhat accurate play for black (Nf6 and Bc5, which are natural moves that they should consider), there really is no good solution for this.
Here you have several sample lines that give an idea of why this opening should be avoided. For example, 1. e4 e5 2. c4 Nf6 3. Nc3 Bc5 4. d3 d6 is more than fine for black, with easy plans and development. This seems like a closed Sicilian gone wrong. Also, 1. e4 e5 2. c4 Nf6 3. d3 Bc5 4. Be2 is pitiful, with white's only "developed" piece being completely shut behind the pawns. Black still has easy plans.
Finally, let's address the issue of giving up the initiative. Since white is no making any threats with 2.c4, black is completely free to just play Nf6 and Bc5 in virtually all variations. Moreover, d6 and Bg4 is a very standard plan, as well as Nc6 aiming for the hole in d4. Since the dark squared bishop is now outside the chain pawn, black has e7 free for a knight, with Nf6-Ne7-Ng6 being a common reroute.
This makes it a difficult variation to play if black makes reasonable moves. I would suggest to play the English opening, and steer the game into closed positions that will benefit from a timely e4 push. For example: 1. c4 c5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. Nf3 Nf6 6. e4, followed by d3.


Why does Fritz prefer underpromotion in this position? Why does Fritz prefer underpromotion in this position? How can underpromotion to bishop evaluate so much higher than normal queen promotion?

Can this be a bug in the Fritz 14 chess engine?

It's because 1. exf8=Q+ Kxh7 2. Rxd7?? would be stalemate. I think it is a even a theoretical draw after 1. exf8=Q+ Kxh7 2. Qg7+. Therefore 1. exf8=B+! (with check!) is better, since white then can keep an extra piece and win easily.

[FEN "5r2/3qPbkB/8/7P/8/8/8/1K1R4 w - - 0 1"]

1. exf8=Q+ (1. exf8=B+!) Kxh7 2. Rxd7? (2. Qg7+)


Why did Kasparov avoid the Marshall Attack?(With White) I read that during Kasparov's long chess career he always avoided the Marshall attack with Anti-Marshalls (h3 and a4). This seems very counter-intuitive to me since the positions that arise from the opening are very double-edged which seem to favor him. I at first thought that it was because he found it hard to get an advantage out of it, but then again he didn't mind facing the Berlin defense to which he basically got no advantage out of. Could someone please help me understand why he never faced the Marshall attack.

Kasparov avoided the Marshall in classical time format

It comes down to one main thing, but there are other factors that probably played a part too. The main thing is that despite the nature of the Marshall attack, it is considered drawish at the highest levels. At lower levels, of course, it is a double-edged game where anything can happen. And while they are double-edged, white is on the defensive, not where Kasparov liked to be.

There is, clearly, a lot of theory to learn, but it is doubtful that Kasparov was put off by that since he had the reputation as the most prepared player in history at that time.

With the advent of computers, the Marshal has been analyzed to the N-th degree (meaning a lot), and most of the time, black has enough initiative to hold the draw, or better if white is not prepared. Kasparov, being Kasparov, probably felt like "why should I allow that possibility when I can probably play a line that you do not get the initiative, and we keep more pieces on the board, and I can simply outplay you in the long run? I am Kasparov, after all."

Lastly, and I touched on this already, but it is simply not Kasparov's style: He is the player, who loves to play with the initiative, so why play into a line that neutralizes his greatest strength? He did not, and I confirmed that by searching Mega 2020, and you are correct: There is not one game in there where he allowed it, and that includes faster time controls. That is not a practical way to play good chess.


What are all the most common transpositions between the Caro-Kann Panov–Botvinnik Attack with 5...e6 6. Nf3 Bb4 and the Nimzo-Indian Defence? I would like to know what are all the most frequent transpositions between the two following openings:

.

The Caro-Kann Panov–Botvinnik Attack with 5...e6 6. Nf3 Bb4:

  [StartPly "12"]

  [FEN ""]
  1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 e6 6. Nf3 Bb4

.

The Nimzo-Indian Defence:

  [StartPly "6"]

  [FEN ""]
  1. d4 Nf6 2. c4 e6 3. Nc3 Bb4

.

Please try if possible to provide the list of all the transpositions sorted from the most common to the rarest.

.

Edit: I found two transpositions which seem to be very common ones.

Both of these two lines:

d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Bd3 d5 6. Nf3 c5 7. O-O cxd4 8. exd4 dxc4 9. Bxc4

d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Bd3 d5 6. Nf3 c5 7. O-O dxc4 8. Bxc4 cxd4 9. exd4

Transpose into this line:

e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 e6 6. Nf3 Bb4 7. Bd3 dxc4 8. Bxc4 O-O 9. O-O

But there are maybe more transpositions.

There are indeed a couple of transpositions from the Nimzo-Indian to the Panov variation of the Caro-Kann and they occur sometimes in practical games.

Using a database of chess games, they can be filtered by searching simultaneously on:

The position after 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4
"B10-B19", i.e. the ECO-code of the Caro-Kann.

After finding the games where an actual transposition occured, they can be put in a tree-like structure to count the transpositions.

Using ChessBase Mega Database 2015, 91 games are found, for which both players have a FIDE rating of 2200 or more. Then, the found games were put in a ChessBase tree-file (.ctg).

The most common transpositions found this way are:

4.e3 0-0 5.Bd3 c5 6.Nf3 d5 7.0-0 cxd4 8.exd4
4.e3 0-0 5.Bd3 d5 6.Nf3 c5 (see 1)
4.e3 c5 5.Nf3 0-0 6.Bd3 (see 1)
4.e3 c5 5.Bd3 0-0 (see 1)


Elo loss for resign vs checkmate Is there a difference in the amount of ELO a player loses from resigning versus being checkmated?

If so - What is the difference in the calculation?

No difference whatsoever.  As with tournament results, ELO (or Glicko, or any other chess rating system) counts all losses the same, all draws the same, and all wins the same.  Doesn't matter if you lose on time, resign, or get mated on the board --- nor whether it took 12 moves or 120.  Likewise a draw is a draw, whether by agreement, repetition, stalemate (either side), or even the 50-move rule.


When is it right to start learning strategy after tactics I have been furiously solving tactical puzzles for 6 weeks now and about three weeks ago I reactivated my account on chess.com.

Long story short I have seen my "rating" go from 1280 to 1590 during this time and for the first time ever I qualified for the second round, not in one but two tournaments on the site so I am definitely seeing improvement.

After asking for the computer analysis for the games that I have lost, I decided to also analyze the ones that I won so I got the last one, which I was feeling particularly good about it, and it turns out that the only reason I won is because my opponent did far worse blunders than I did. If he had been just a little bit stronger he would have crushed me.

I have followed the recommended variants and I just cannot understand why the position I ended up with is far worse than the one the computer recommends. I have zero understanding of positional play.

I feel that I still need A LOT of tactical practice, I still miss quite a few solutions from rather simple puzzles, but I am wondering if by not knowing strategy all this tactical knowledge might go to waste because of mistakes and blunders during the games.

So the questions would be:
- When is it a "right" time to start easing off on the tactical training to start balancing it with strategy/positional one?
- If I focus on these two, is there some kind of heuristic as to how to balance that training (20% - 80%, 30% - 70%, 50% - 50%)?
- As a bonus, if you could recommend some basic literature for someone who has absolutely zero understanding of positional play it would be appreciated.

Thanks.

Improving positional understanding is a longterm project. You do it by playing, by analysing, by going through well annotated master games and by working through books on the subject. But contrary to tactical exercises these things often don't have an immediate effect. Personally I also misapplied a lot of positional concepts that I had read about. Positional understanding will only help you if it is complete on some level. As soon as that happens there often is a sudden rise in strength.

Given that successfully applying positional concept depends a lot on accurate calculation, the right time to get really serious about training positional understanding is probably when you start getting diminishing returns from your tactical training. It's unlikely that you are at that point yet.

But if you have fun doing the things I mentioned at the beginning, there is no reason not to do them. Just remember that you will probably misapply ideas and not necessarily see immediate benefits. And try to not be too dogmatic about the things some authors tell you. The main thing is the discovery of amazing ideas and possibilities in chess.

Nimzowitsch: My System, a classic, it was definitely revelatory to me and also a lot of fun to read because of the evocative prose. (I don't know about the english translations though.)
The Yusupov-Series: Very systematic training of all aspects of the game. If you hit a wall in pure tactics training, the orange books might take you to the next level.
John Nunn's Move by Move: Just one example of many well commented game collections. This one literally explains every move, making it more suitable for relative beginners.


East and West German Chess Interested in chess history, I wonder if there is an accessible data set that lists all players from East and West Germany in the 80's, ideally with information like the FIDE website (name, national Elo rating, gender and year of birth). I would also be interested in the same data for Germany in the 90s and 2000s.
Note 1. Wikipedia lists I know are too sparse (East German or German players).
Note 2. @BrianTower's answer is very useful but I'm afraid that by focusing only on FIDE players I would miss good players who were not FIDE rated because of the old rating floors for men (2205) and women (2005).

I wonder if there is an accessible data set that lists all players
from East and West Germany in the 80's

The Olimpbase site has a downloadable zip file of FIDE rating data from 1967 to 2001. It is accessible in the sense that you can download it but the data you want would have to be extracted from the dataset which isn't in an easily readable form. It is also quite "dirty".
Now I have already done this so for me it is just a matter of executing the right sql command. Here are the results for East German players. Note that FIDE Ids came in just as the GDR ceased to exist so some of the players don't have proper FINs. Nevertheless my DB requires a unique FIN for each player so the shorter FINs were either the 5-digit, one-year FINs which FIDE created initially before they thought maybe they should cater for more than 100,000 players or they were auto-constructed by my load program.
FullName    FIDEID  DoBYear Sex MaxRating
Apel, Stefan 4612116 1969    M   2265
Aring, Gerd  4665791 1963    M   2230
Babrikowski, Peter, Dr.  4611942 1956    M   2320
Bade, Heidrun    4612710 1945    F   2040
Barth, Rainer    4611918 1958    M   2280
Bauer, Reinhard, Dr. 4611772 1954    M   2310
Baum, Bernd, Dr. 4611853 1945    M   2265
Baumbach, Friedrich, Dr. 4611721 1935    M   2460
Becker, Michael  4611667 1957    M   2330
Belke, Frank, Dr.    4612337 1963    M   2230
Beltz, Martina   4612485 1962    F   2160
Besser, Hans 4601033 1935    M   2460
Birke, Andreas   4612140 1966    M   2255
Boehlig, Heinz, Dr.  4614283 1943    M   2450
Boehnisch, Manfred   4611543 1941    M   2390
Boensch, Uwe 4611268 1958    M   2575
Boettcher, Ilse  17753   NULL    F   2045
Bonsch, Uwe  17771   NULL    M   2505
Borriss, Martin, Dr. 4611950 1970    M   2300
Brameyer, Hermann    4612019 1939    M   2270
Braun, Gottfried, Dr.    4611489 1933    M   2400
Braun, Regine    4612744 1954    F   1910
Broeder, Iris    4612426 1962    F   2225
Broemel, Richard 4612256 1958    M   2240
Bromel, Richard  78522   NULL    M   2240
Brueggemann, Joachim 4611861 1951    M   2365
Bueder, Thomas   4612183 1967    M   2260
Burchardt, Brigitte  4612213 1954    F   2295
Camin, Gesine    17844   NULL    F   2020
Casper, Thomas   4611403 1959    M   2435
Csulits, Anton   4611705 1942    M   2345
Daemering, Katrin    4612604 1966    F   2100
Dietze, Wolfgang, Dr.    4611802 1950    M   2340
Enders, Peter    4611314 1963    M   2490
Espig, Gesine    4612523 1959    F   2135
Espig, Lutz  4611276 1949    M   2490
Espig, Thomas    4612027 1954    M   2380
Feibert, Petra   4606191 1958    F   2255
Feustel  18116   NULL    M   2305
Frommelt, Hans-Juergen   4612159 1954    M   2255
Fuchs, Reinhart  4611357 1934    M   2460
Gaffron, Petra   18169   NULL    F   1820
Gauglitz, Gernot 4611365 1962    M   2480
Gautzsch, Christina  4612620 NULL    F   1980
Geibler, G.  18204   NULL    F   2055
Geissler, Grit   4612655 1967    F   2050
Goehler, Antje   4612469 1967    F   2220
Goldberg, Alexander, Dr. 4611560 1965    M   2340
Golz, Werner 18253   1933    M   2410
Grigorov 18292   NULL    M   2205
Grottke, Hans-Joachim, Dr.   4612167 1942    M   2280
Gruenberg, Hans-Ulrich   4611306 1956    M   2510
Hackel, Mario    4611780 1970    M   2360
Harnisch, Diana  4612531 NULL    F   2025
Hartlapp, Jutta  4612612 NULL    F   1985
Heinatz, Dr. Gundula 4612434 1969    F   2195
Heinatz, Thomas  4611748 1965    M   2355
Heinen   18363   NULL    M   2265
Heinig, Wolfram, Dr. 4611926 1954    M   2365
Heinsohn, Guenther   4641140 1945    M   2235
Heinsohn, Wilfried   4612400 1947    M   2215
Heintze, Marion  4612191 1954    F   2235
Hennings, Artur  4611594 1940    M   2475
Hesse, Peter 4611519 1944    M   2440
Hobusch, Cornelia    4612574 1960    F   2000
Hoeckendorf, Hartmut 4612302 1954    M   2255
Hoelzlein, Christina 18391   1951    F   2140
Hoffmann, Helga  4608933 1932    F   2015
Hoffmann, R. 18392   NULL    F   2205
Hofmann, B.  18393   NULL    F   2230
Jahn, Constanze  4612450 1963    F   2210
Jahnel, Guenther 4636147 1958    M   2315
Jakat, Thomas    4612329 1959    M   2270
Janssen, Lieselotte  4612515 1937    F   2040
Jaster, Robert, Prof. Dr.    4612418 1964    M   2225
Jeske, Eckhard   4641485 1952    M   2235
Jeske, Kirsten   4612728 1963    F   2025
Just, Gabriele, Dr.  4612558 1936    F   2155
Kaminski, Uwe    4611381 1962    M   2405
Keller, Manfred  4607368 1945    M   2325
Keller-Hermann, Edith    4611870 1921    F   2190
Kestler, Hans-Guenther   4601076 1939    M   2450
Kimpinsky, Frank 4611934 1960    M   2300
Kleeschaetzky, Rainer    4611985 1963    M   2290
Kliefoth, Christel   4612752 1957    F   1880
Kluss, C.    18592   NULL    F   1880
Knaak, Rainer    4611250 1953    M   2565
Kobe, U. 18597   NULL    M   2270
Kobe, Ulrich 4612035 1941    M   2270
Kopfer, Michael  89915   NULL    M   2235
Kosowski, Todor  4612310 1970    M   2235
Kroggel, Rita    18658   NULL    F   1840
Krug, Peter  18662   NULL    M   2220
Kube, Hannelore  4612760 1953    F   2005
Kunze, Kerstin   4612493 1971    F   2215
Kyas, Juergen    4618157 1955    M   2230
Lamm, Steffen    4612175 1963    M   2280
Lang, Jens, Dr.  4611756 1960    M   2315
Lehmann, Christina   4612442 1951    F   2075
Lenk, Wolfgang   4612388 1938    M   2250
Liebert, Heinz   4611438 1936    M   2485
Litkiewicz, Kurt 4612264 1934    M   2240
Lorenz, Gerd 4612272 1944    M   2275
Luther, Thomas   4611420 1969    M   2425
Malich, Burkhard, Dr.    4611330 1936    M   2535
Manger, Carola   12092   1959    F   2110
Meissner, Hans-Juergen   4611969 1953    M   2290
Melzer, Monika   4612680 NULL    F   1940
Mevissen, Ulrich 4612736 1938    F   2025
Moehring, Guenther   4611462 1936    M   2450
Mueller, K.  18988   NULL    F   1870
Mueller, Klaus   4611578 1942    M   2470
Mueller, Werner  4612370 1954    M   2215
Mueller, Werner  18992   NULL    M   2205
Neukirch, Detlef 4611624 1940    M   2375
Nobis, Martina   4612779 1959    F   2005
Nowarra, Waltraud    4612361 1940    F   2120
Nuenchert, Eveline   4612540 1943    F   2145
Oetzel, Roland   4612043 NULL    M   2270
Okrajek, Alexander   4612221 1956    M   2230
Pachow, Joerg    4612230 1961    M   2255
Packroff, Hermann    4611896 1941    M   2290
Paehtz, Thomas   4611349 1956    M   2515
Petigk, Falk 4611373 1930    M   2420
Pfeil, Hartmut   4611810 1951    M   2300
Pfretzschner, Roland 4612086 1958    M   2265
Poldauf, Dirk    4611470 1965    M   2390
Pollak, Georg    4611551 1946    M   2350
Postler, Reinhard    4611608 1944    M   2375
Pranner, Marion  4612582 NULL    F   1990
Prussas, Claudia 19262   NULL    F   1835
Raitza, Olaf 4611675 1934    M   2325
Ramseier, Jana S.    1302329 1969    F   2080
Riecks, A.   19343   NULL    F   1805
Roesch, Arnd, Prof.  4611632 1965    M   2335
Roesler, Matthias, Dr.   4611977 1966    M   2270
Rosenthal, Dirk  4611586 1970    M   2280
Rossmann, Helmut 4612094 1956    M   2360
Rozental, D. 19388   NULL    M   2305
Ruebensam, Helmut    4612051 1955    M   2270
Schilar, Michael 19465   NULL    M   2225
Schmidt, Gerhard 4605233 1940    M   2275
Schneider, Frank 4612299 1945    M   2240
Schoene, Ralf    4611535 1961    M   2310
Schoeneberg, Manfred 4611845 1946    M   2470
Schurade, Matthias   4611497 1959    M   2385
Seidemann, Ulricke   4612639 1955    F   2080
Seils, Gudula    4612671 1961    F   2045
Seils, Joerg 4612078 1963    M   2255
Skibbe, Diana    4612698 1961    F   2040
Sommaro, Katja   4612590 1966    F   2135
Starck, Bodo 4611829 1934    M   2325
Starck, Ines 4612477 1963    F   2135
Stern, Rene  4611799 1972    M   2335
Stettler, Michael    4611454 1961    M   2375
Syre, Christian  4611993 1954    M   2285
Teske, Henrik    4611500 1968    M   2425
Thal, Olaf   4611683 1935    M   2355
Thormann, Wolfgang   4611713 1949    M   2360
Tischbierek, Raj 4611322 1962    M   2500
Uhlmann, Wolfgang    4611284 1935    M   2590
Vogt, Lothar 4611292 1952    M   2520
Volke, Karsten   4611411 1965    M   2395
Wagner-Michel, Annett    4612205 1955    F   2230
Walter, Guenter  4612108 1942    M   2370
Weyrich, Morten  4611659 1959    M   2290
Wieland, Ilse    4612507 1957    F   2045
Wolf, Sylvia 4612701 1962    F   2025
Wolff, Sonja 19903   NULL    F   1815
Womacka, Mathias 4611390 1966    M   2395
Zahn, Juergen    4612345 1946    M   2225
Zinn, Lothar 19958   1938    M   2435
Running the same query for Germany gives almost 1100 rows which is too much to post here IMHO. If you can find a way you are happy with sending me an email address I can send you some bigger query results.


Creating the current position having the rest of the game It's a question a friend of mine brought up and I found intriguing.
Let's say you have the records of a game from a certain move to the end, using standard notation (i.e. Qf6).
Either assuming random play or strong play (which is really hard to define), how many more moves on average would you need to restore the current position?
I don't really know how to approach this question, but it seems to involve retrograde analysis. The factors I could come up with are these.

Knowing where a piece moved to tells you it's possible locations.
Knowing where a piece moves tells you about empty squares (on the piece's way). This of course depends on it's original location.
Checks give you information about both the location of the king and empty squares around it
Exchanges give you a lot of info, both about the exact position of a piece and about the squares around it.
Castlings give you info about 5-6 pieces.

Another variant to this question is where the starting square of a piece is also given in the notation, i.e. Nd5-e3 instead of Ne3. This is not the most popular notation but it's still usable. How much would it affect the result?
P.S. Why does CSE have no "soft question" tag?

Fascinating question! By definition, I can only come with a partial solution, or more accurately "elements" that will be part of the retro analysis. I know I'll be thinking about this more, but here are a few initial thoughts.

Just a few more 'factors' to add to your list:

We'd need a certain minimum number of moves (in the latter part of the game) to make any meaningful analysis.
If the game is played out (i.e.) ends in a mate, that would help in recreating the 'start' position.
If the starting square is given, then it will help immensely.
Knowing the move number would help. (Is it 19 Ne5 or 24 Ne5)
The idea of "candidate squares" for pieces. If Na1 was played, then the N must have been at b3 or c2. For a N to reach c2, it must have come from... In effect, we know there must have been a few moves to get the knight from b1 or g1.
Pawn moves give us 'definitive' information about the 'from' square (except for e2-e4 vs e3-e4 type double jumps) Bishop moves help because they stay in the same color.

We could infer more, but these is a start.

Alt. solution If you were allowed to "cheat" (lateral thinking):

you could feed the moves to a good-sized database and see if it can match up a game.
Chessbase has advanced search features which let you search for positions by pieces occupying squares, and also by a sequence of moves.

We could even do try this out with an actual snippet of a game. Publish, say the last 20 moves of a 50 move game, and try to recreate the position at move #30, without cheating or referring to a chessDB.


Can White win this knight endgame? [Title "Black to move"]
[StartFlipped "0"]
[fen "8/p2N1pk1/1pn1p1p1/2p1P2p/5P1P/2P3P1/PP6/6K1 b - - 0 1"]

I thought that I had advantage as White since I was able to temporarily cutt off Black king. I have underestimated Black's counterplay on the queenside with ...Na5, misplayed it and drew.

The more and more I analyze on my own, the more and more I start to wonder: Did I have any winning advantage at all, or was my position just "prettier" ?

You definitely had an advantage, but it's a bit of a challenge to turn that into victory. If you don't use all of your advantages and his disadvantages, it can quickly turn into a draw.

In this position, your main advantage is your Knight - it can jump very easily between very useful squares d7-f6-e4-d6.
Your King can be activated very easily in the next few moves, while black King is quite passive and has limited movement due to your Knight and Pawns (both yours and his) blocking him.
Moreover, your Knight can't be threatened at d7, so it's your decision when to move it (and give his King some breath).

His ...Na5 is a logical choice from his side, but you have nothing to fear, your aim is to get your King closer to the center (Kf2-Ke3) and also put Pawn on b3 (not if he pulls back with his Knight, of course) to disable any chances of his Knight getting through (preferably he plays Nc4 before you play b3, so you play that move with gaining a tempo).

However, the problem you have is that you can't go too far away with your King. Ideally you would come to the Queen side and take his Pawns, while his King watches helpessly; but you can't do that as he threatens Ne7-Nf5, which leaves your g3 Pawn at his mercy if your King isn't there to defend it. Now, you can try to exchange your g3 Pawn (Kf3 or Nf6 followed by g4), but that leaves you with weak h-Pawn which he can attack easily with his King (Kh6-Kh5) or/and his Knight (Nf5).

The best thing to try (after b3 and after your King is a bit activated on e3-d3) is to get your Knight back to e4 (Nf6-Ne4) to defend g3-Pawn so you can proceed with your King to the Queen side:

[StartFlipped "0"]
[FEN "8/p2N1pk1/1pn1p1p1/2p1P2p/5P1P/2P3P1/PP6/6K1 b - - 0 1"]

1...Na5 2. Kf2 Nc4 3. b3 Na5 4. Ke3 Nc6 5. Kd3 Ne7 6. Nf6 Nf5 (6...Nd5 7. Ne8+ Kf8 8. Nd6 Ne7 {Otherwise, you win a Pawn with Nc8} 9. a4 a6 {Black is lost otherwise, he either lets your Knight to c8 or your King inside} 10. a5 bxa5 11. Ne4 Nd5 12. Nxc5 Nc7 13. c4 Ke7 14. Nb7 {And you are a Pawn ahead}) (6...Nc6 7. Kc4 a6 8. Nd7 Ne7 9. Nxb6 Nf5 10. a4 Nxg3 11. Kxc5 f6 12. Nd7 {And now you don't have any trouble promoting on the Queen side on time}) 7. Ne4 Ne7 8. Kc4 a6  9. Nd6 Nc6 10. Nc8 Na5+ 11. Kd3 b5 12. Nb6 Nb7 13. Nd7 a5 14. a3 {Now black has no good moves} Kg8 15. a4 c4+ 16. bxc4 bxa4 17. c5 Nd8 18. Kc2 {You can pick up his a-Pawns and push c-Pawns afterwards} 1-0

But note that I didn't perhaps show the best black defense here. Although, to be honest, with his King that limited, he didn't have many options. If he tries to get his Knight to f5 before he provoked your b3, you can play a4-a5 and his defense on the Queen side is ruined. He can only perhaps try to push his Queen side Pawns and pray that he can somehow block you in time, although it's a very hard fight for him:

[StartFlipped "0"]
[FEN "8/p2N1pk1/1pn1p1p1/2p1P2p/5P1P/2P3P1/PP6/6K1 b - - 0 1"]

1...Na5 2. Kf2 Nc4 3. b3 Na5 4. Ke3 c4 5. b4 Nc6 6. Nf6 Kf8 7. Ne4 b5 8. Nd6 a6 9. Ne4 Ke7 10. Nc5 a5 11. bxa5 Nxa5 12. Ne4 Nc6 13. a3 Kd7 14. Nd6 f6 15. Nxb5 fxe5 16. fxe5 Nxe5 17. Kd4 {And now you win a Pawn and have an easy way to victory} 1-0

All in all, your advantage was a bit more substantial than just "prettier" position, at least in my opinion.


Position-jugdment problems simulating actual play I'm interested in collections of chess problems
where we are not told beforehand what is happening in the positions presented,
but we have to decide by ourselves, whether something clear exists (a winning or drawing combination, a good move or plan that keeps the initiative) or whether the position presented is still unclear. Clearly the goal is to exercise analysis, intuition and general judgment of positions, by simulating actual play.
So are there collections of problems of this type, in print or online?

You can find such positions in Dvoretsky's books.  Also, in "The Defense Triumphs" by Kotov. But in general I am not aware of a collection of positions without a clear objective presented.

Then there are a couple newer "positions you must know" books that you might explore.

Of course if you go over annotated GM games as if you are playing the game, thinking before reading the next more or comments -- this is a good way to achieve such training.


Touch move and capture sequence When considering the touch move rule, I am still unclear about the legal sequence for a capture. Example, white intends to capture a took on a8 with rook on a1 (open file). Does white have to touch black's rook
first? The way I read the rule, if white touches a1 first, they can only play a2 through a7, since touching a8 AFTER a1 violates the rule. What is the legal sequence?

Here is what the FIDE Laws of Chess have to say:

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

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

So, if the first two pieces you touch are one of your pieces and one of your opponent's pieces then you must capture your opponent's touched piece with your touched piece. Order is irrelevant in this case.

If you first touch your piece and then one of your opponent's pieces which you cannot capture with your touched piece then you must move your piece even if you can capture your opponent's touched piece with one of your untouched pieces.

If you first touch one of your opponent's pieces and then one of your pieces but can't capture the opponent's touched piece with your touched piece then you must capture your opponent's touched piece if you can. Otherwise you have to move your touched piece.

Overriding these rules is the rule preventing you from making an illegal move. You may only move a touched piece or take an opponent's touched piece if that move is legal.


Will computer knowledge reach a perfect game, after expanding prepared openings/endgames? If computers just check in an openings-DB what to do in the first 10, 15 or even 20 moves, and if they just check the endgames-DB at the endgame; wouldn't it reach a point where they have a DB of perfect games that goes from opening to endgame?

To my mind, what you are asking is can a computer ever "know" the correct move and evaluation in every conceivable position. Without such complete knowledge, it wouldn't be possible to play perfectly because every evaluation is dependent on evaluations of the multitude of possible upcoming positions. This perfection is what endgame tablebases provide. Outside of contexts where distance to mate can be calculated, tablebases are the only context in which computers have a "perfect" understanding of a position. For reference, 5 piece tablebases (e.g. 2 kings and 3 other pieces) require 7 GB of storage. 6 piece tablebases require 1.2 TB, and 7 man tablebases are only recently completed and require 140 TBs. To solve chess completely, you would need a 32 man tablebase.

The problem is comparable in fictional magnitude to the calculation of the "Ultimate Question of Life, the Universe, and Everything" as depicted in Hitchhiker's Guide to the Galaxy. In that case an entire planet, was devoted to identifying the question. It seems an equally pointless and gargantuan task to attempt to "solve" chess.

Just to put your mind at ease... even though computers may play well above the level of the best humans today, there are still plenty of decisive games between top level computers today. Check out the ongoing TCEC tournament. Clearly, computers are still quite capable of mistakes.


What's the point of 7 Kf1(Krakow Variation) of the Italian game? The variation goes(I will do it through the scotch gambit)

[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR b KQkq - 0 1"]
1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 Bc5 5.c3 Nf6 6.cxd4 Bb4+ 7.Kf1 (7.Bd2)(7.Nc3)

I suppose the alternative is to play Bd2, but I believe that black manages to often hold a draw here because of theoretical repetition lines. White could of also played Nc3, though tricky, Black seems to be doing fine if they know the theory. Thus, it seems like Kf1 is played to avoid a draw.
However, if avoiding a draw is desired, why not simply play e5 instead of cxd4?
Is there really anything in this Kf1 variation or is it harmless?

I guess it's a surprise weapon, no need to be excellent objectively. The position is around equal after Kf1 and black must deal with new situation, while white probably knows what to do next moves. Black must deal now with vulnerable bishop on b4 and two connected central pawns. He goes wrong, he can get into trouble. He goes right, the position will be normally playable for white. The point is not to allow the bishop b4 to be exchanged. This bishop can run to various tactics.


Chess movies in Hollywood & Bollywood with GMs in them Are there any movies about chess in which World Champions or grandmasters have played actually any role? For example, have Kasparov, Karpov, Anand, Carlsen, Kramnik, Polgar, Fischer, Tal or etc acted in the movie?

Check out Grossmeyster. Mikhail Tal exchanges a few words with the main character. Keres, Kotov, Taymanov, Averbakh have cameo appearances. Victor Korchnoj plays the main character's coach.
I don't know if the English version exists.


Why does FIDE classical chess have a time limit for the first 40 moves? From this answer:

The FIDE-approved classical time control is: (taken from the handbook)
07 Time Control There is a single time control for all major FIDE events: 90 minutes for the first 40 moves followed by 30 minutes for the rest of the game with an addition of 30 seconds per move starting from move one.

Why is 40 moves special? Would the right increment handle this problem? I'm puzzled why there is a special time control for the start of the game, it seems an artificial constraint. What is the logic behind this?

Factually you ask two different things, "how" and "why", and maybe considering the "how" first makes things clearer.
Obviously, the FIDE time control is recent. In early history of chess there was no time control at all, the problem with that should be obvious. I am old enough to have played 40 moves/2 hours + adjournment, thus it's more recent than you might think.
Now to the "why". There is nothing special with 40 moves or two hours. Clearly 41 moves would be silly, man automatically thinks in round numbers. I daresay (experienced from thousands of tournament games, and only judging from the time spent by my opponents - I'm a notorical "blitzer") that 30 moves are too short: the hectic of time trouble would hit the midst of a game. 50 moves are too long - we are in the endgame already and could as well play it out. The same holds for "2 hours" which is not as carved in stone as you might think, I played lot of games in lower leagues with shorter, and also in higher with two time controls (40/2h+20/1h+rest/30m).
That said, the standard time control before the invention of electronic chess clocks was just a rounded compromise - almost anyone could live with it. Nowadays, indeed almost all games (at least the "top" ones) are played with Fischer bonus, which admittedly has advantages, especially for the referees (I'm one too and can acknowledge that).
tl;dr: No logic, just evolution, which includes clinging to accustomed numbers. If chess would be invented today, one might converge to another time control.


Why Stockfish 9 fails to see the draw? I can reach a draw with White in the below position. The Stockfish 9, however, gives 28.1 points for black after Kf3,Ba1,Ke4,Bb2,Kd3.

[FEN "8/p7/kpP5/qrp1b3/rpP2b2/pP4b1/P3K3/8 w - - 0 1"]

1. Kf3 Ba1 2. Ke4 Bb2 3. Kd3 Ba1 4. Ke4 Bb2 5. Kd3 Ba1 6. Ke4 Bb2 7. Kd3 Ba1 8. Ke4

Why Stockfish 9 fails to see the draw?

...... Stockfish isn't designed for solving a position like this. It's being written to play a good game of chess. Your position is not a position that SF should give an equal score.

The engine doesn't understand there's no mating possibility if White does nothing but moving the king. It gives a high score for Black because of the extra materials. Humans wouldn't even consider with any of the pawn capture, but SF has no idea.

Unfortunately, SF doesn't have the power to solve chess.


Which notable players in chess history successfully used dubious openings? I am reminded of a famous game between Karpov and Tony Miles where Miles played 1...a6 against Karpov's 1. e4 and still won the game.

     [FEN "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1"]
     [White "Anatoly Karpov"]
     [Black "Tony Miles"]

     1...a6?!

Which other players in chess history have used dubious openings successfully? Which were the openings?

NOTE: For the purpose of this question, the player (or the opponent) must either have been a world champion (like Karpov in this game) at some point or at least a strong contender for the world title during his time. Also, the openings must have been considered to be dubious during their time.

If you really mean "dubious", then no one really fits this description since Steinitz, who liked to, for example, go for walks with his King when playing the King's Gambit as White. But people didn't really know better back then.

If you're willing to relax "dubious" to "offbeat", the first player that comes to mind is Bent Larsen, one of the strongest players in the world in the 1960s and 1970s. He regularly played 1.f4 and 1.b3 (often known now as Larsen's Opening), and also helped revive the Bishop's Opening and the Philidor Defense. None of these were regarded particularly seriously by top-level players at the time that he adopted them.

Before that, players like Réti and Nimzowitsch developed hypermodern theory, in which players tried to control the center from afar instead of occupying it with their pawns. Some players regarded this strategy as dubious but it shortly became clear that it was perfectly legitimate.


Does deliberately knocking the king over end the game? When I play with my friend, he will often knock his own king over when he is going to lose.

He ends the game and says, "I lose".

Is this permissible?

Yes, players often tip their king over to indicate that they are resigning.


The early ...Qf6 in the Scotch Game In the Scotch Game, what is the best move for White after this sequence?
[FEN ""]

1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Nxd4 Qf6 5. Be3  (5. Nb5) (5. Nf3) 5...Bc5

Most videos don't even count Qf6 as a respectable move. However, how to counter it? I'd go for either Be3, Nb5 or Nf3 but I would like your advice.

EDIT: How about Nb5 after Qf6, threatening a fork? Nf3 is actually the best move according to the chess.com engine Perhaps this is enough to give White an advantage because of a too early black queen development.
My heart goes towards the more aggressive Nb5 though.

The queen move threatens the d4 knight. Also keep in mind that your opponent might play Bc5 later to get another attacker on the knight and pressure f2.
Bc4 or Nc3 don't protect the knight, so they lose a piece. You can reject those moves.
Be3 seems OK. Moving the d4 knight to b3, b5, or f3 seems fine, as does Nxc6. I wouldn't want to play an immediate c3 to protect the knight, since I'd rather put my b1 knight on that square later.


Why is Ne2 better than Nf3? I played Nf3 for attacking on king side which is about to castle having some plans to make a battery in future after castling but I feel Ne2 is making a block for Re1 at some point. Any suggestions?

[fen "rnbqk2r/pp3ppp/2p3n1/3pP3/3P4/2PB4/P4PPP/R1BQK1NR w KQkq - 0 1"]

While the knight wouldn't be badly placed on f3, playing Ne2 keeps your f2-pawn unblocked, allowing you to push it up the board. If the pawn reaches f5 then you will have an overwhelming position. Also, on e2 the knight could go to g3, helping to control the f5-square while eyeing the h5-square.


Can Black create the second weakness? I have played blitz game on lichess as Black and entered into drawn bishop endgame. My opponent tried to force the matters and lost in the end but at some point very interesting position arose, where White had only one permanent weakness.

I am interested to know if Black can win the following endgame by creating second weakness in White position, or simply breaking through with his king.

[Title "Black to move"]
[fen "8/p7/2bk1p2/2p3p1/5PP1/1B4K1/PP6/8 b - - 0 1"]

After 1...Bd5, Black can win at least a pawn. White cannot take on d5 because that's a clearly won king endgame for Black- Black threatens to go Kd4-Kd3-c2 and take the pawn on b2. If White tries to defend with Ke2, then Ke4 from Black wins the g-pawn and the game.


A position in which checkmate is forced (obligatory) I am looking for a position in which all possible moves are checkmate. This means, that if the player does not want to checkmate the opponent, because for example he feels sorry for him, even in that case he is forced to checkmate him. He cannot avoid it. Can you tell me an example? White or black does not matter.

Also, I feel this can be done only if there is a very small number of possible moves. For example 1 or 2.

I just remembered a class of chess problem; see item 267 of Tim Krabbé's Open Chess Diary (his whole site is highly recommended):

[Title "White mates in 7, Noam Elkies, 2004."]
[FEN "KBk5/P1P4p/2Pp3P/P6p/2p3rP/2P3pB/6P1/8 w KQkq - 0 1"]

Spoiler: White has some choices here, he can choose different move orders. But it's always checkmate on move 7, no matter what.


Using the tree window in SCID on a subset of games in the database With a database open in SCID, one can use the tree window to explore openings.  Among other things, it shows the frequency of each move that has been played in the current position and how well that move has scored.

Is there a way to combine this with SCID's filter functionality so that the tree window only uses the subset of games selected by the current filter?  For example, this could be used to explore openings based on 2600+ games or games where the opponents are close in rating.

It is possible to do this by creating a copy of the database and then removing all games that are not in the filter, but this is an inconvenient workaround.  Is there a better way?

Yes. In the tree window, there is an "All Games" checkbox. Unchecking this will make the tree window use the filtered games instead of all the games.


What is the farthest away a game can be from a guaranteed checkmate? What is the maximum number of moves away from checkmate that a player can be where checkmate is guaranteed? There are many positions that are a guaranteed win for a player if played perfectly, right? (Obviously there is not a guaranteed win from the first move). My question is: What is the furthest amount of moves one can be from guaranteed checkmate, when the shortest amount of moves to checkmate is taken?
Let's assume you are white and have, say, a bishop and a knight left and black is down to just the king. (there is a way to get checkmate with a bishop a knight, so checkmate is assumed to be guaranteed). Now, one set of moves could take say 40 moves to get checkmate from this point, but the least number is say 19 moves away. Now, my question is asking what the most amount of moves to guaranteed checkmate is, but you have to take the route to checkmate that has the least amount of moves, so 19 would be the case from the point where the bishop and knight are the only pieces other than the kings left.
I apologize for the lengthiness of this question, I couldn’t think of a good way to ask what I’m asking. This question derived from wondering if black or white could win every time from the first move but obviously that isn’t the case. The main question is at the end of my first paragraph.
Edit: 50 moves without a pawn push or a capture does not trigger a draw.

I doubt that anyone will be able to give you a definitive answer beyond this one, but the longest known win from the end of a game is a famous 549-move 7-piece tablebase win. Until we get to 8-piece tablebases, this is probably the longest anyone can prove.

You can see that position, and all 549 moves here.


Is this a smart draw offer? [Event "Live Chess"]
[Site "Chess.com"]
[Date "2018.12.27"]
[White "SergioRamos2"]
[Black "SmojLee"]
[Result "1/2-1/2"]
[ECO "B57"]
[WhiteElo "1640"]
[BlackElo "2175"]
[TimeControl "600"]
[EndTime "10:48:30 PST"]
[Termination "Game drawn by agreement"]
[CurrentPosition "8/3kb1p1/7p/6p1/8/3K4/6PP/4R3 b - - 1 54"]
[FEN ""]

1.e4 c5 2.Nf3 d6 3.Nc3 Bd7 4.Bc4 Nc6 5.O-O Nf6 6.d4 cxd4 7.Nxd4 a6 8.f4 Qb6 9.Be3 Ng4 10.Nd5 Nxe3 11.Nxe3 Nxd4 12.Kh1 Nc6 13.Qe2 e6 14.Rab1 Be7 15.c3 Qc7 16.a4 O-O 17.Bd3 Rfd8 18.Rf3 Rac8 19.Rh3 h6 20.Rf1 Bf8 21.Rg3 Ne7 22.Qh5 Ng6 23.f5 exf5 24.exf5 Qc5 25.b4 Qe5 26.Ng4 Qd5 27.c4 Rxc4 28.Bxc4 Qxc4 29.Rd1 Qe4 30.fxg6 fxg6 31.Qd5+ Qxd5 32.Rxd5 Bxa4 33.Kg1 Bc6 34.Rd4 d5 35.Ne5 Bd6 36.Nxc6 bxc6 37.Ra3 c5 38.Rd1 c4 39.Kf1 Bxb4 40.Rxa6 Kf7 41.Ra4 Be7 42.Ra5 Ke6 43.Re1+ Kf6 44.Rd1 Rc8 45.Raxd5 c3 46.Ra5 g5 47.Ke2 Kf7 48.Ra7 Ke6 49.Kd3 Kf7 50.Rf1+ Ke8 51.Re1 Rd8+ 52.Kxc3 Rd7 53.Rxd7 Kxd7 54.Kd3  1/2-1/2

This is a game I had with black and I was doing well with time and position but it came down to one move that made me lose!  Luckily my opponent is time trouble so he had to offer a draw. Was it smart of me to accept it since he was up by +1 and he only had 40 seconds left? I would appreciate if someone could analyse the game to see what went wrong,   thank you!

My first thought was that black had won a piece by move 12, and should have been able to win without getting into such heavy complications. For instance, a move like 15...Qc7? is just a bad move from a strategic standpoint. It's not necessarily losing or anything, but black doesn't know for sure where the queen is supposed to go, whereas black knows for sure that the king should get to safety. This is a good rule of thumb: begin by dealing with the pieces you know where they are going before manoeuvring with the pieces for which it's unclear where they stand better.

Basically what went wrong for black in this game is not a one-move mistake in my opinion. Black went on with a standard plan in the open sicilian, ignoring the fact that white was preparing a kingside attack. This made everything very awkward in the end, and once white's attack was actually picking up steam it was already unneccessarily difficult for black to respond properly. I'm sure that one could make detailed remarks on many of the moves played in this game, but noting that this was a 10-minute blitz game I see little reason to make a detailed analysis of this game. One suggestion I would make for black in this game is that black should've played 11...Qxd4 instead of 11...Nxd4. The reason is that black is already a full piece up at this point, and if the queens are traded white is just doomed, since there will be no talk about kingside counterplay then.

As for the question about the draw offer, black has zero winning chances in the final position. In general, it's never a bad idea to accept a draw offer in a worse position even if your opponent is low on time, and this is no exception to that rule. 40 seconds is enough for white not to blunder a rook, and realistically black is the only one actually risking anything by playing on. But in the end I think the position is drawn and I see no good try for white to actually make any progress.


Is the Reversed Sicilian / King's English 1. c4 e5 more of a positional and quiet opening or a wild and tactical opening? The only thing that deters me from playing 1. c4 followed by a Kingside Fianchetto is 1...e5 the Reversed Sicilian (also called the King's English).

I like quiet, positional, strategic and maneuvering games (not wild tactical games with direct attacks on the Kings), but I'm not so sure if 1...e5 will lead to that kind of games.

I know that any opening can be tactical or positional: some Sicilian Najdorf are very boring, and some Slav Exchange are extremely wild...

But I would like to know on average if 1. c4 e5 tends to lead to positions which are closer to being 'quiet, solid, positional, strategic' or closer to being 'sharp, wild, tactical, chaotic'.

I would definitely classify these positions as rather quiet. Black is lacking the tempo to build up an attacking position, like white does in the sicilian:

For example in this line the knight usually goes back to b6, something white (i.e. Nb3) would never play against the dragon. And of course d4 is much easier to achieve for white here, than d5 is for black in the sicilian. That'll lead to some exchanges with white banking on his strong g3-bishop.

[FEN ""]
1. c4 e5 2.Nc3 Nf6 3.g3 d5 4.cxd5 Nxd5 5.Bg2 Nb6

Of course you still have to pick the right subvariations to avoid sharp lines, but that should be an achievable task. If I knew a variation that forces a sharp tactical fight onto white, I would play it with black. But I don't.


Giving moves as odds, what's the least number of moves by White which forces checkmate by the time it's Black's turn? If one player (Black) gives another player (White) odds of x moves, stipulating that White must not move any man beyond his fourth rank until Black has made one move, what's the smallest value for "x" that would force checkmate by the time it is Black's turn to move?  And what would those x moves be?

Interesting puzzle.

I came up with this.

[FEN ""]

1. d4 null 2. Qd2 null 3. Qf4 null 4. a4 null 5. Ra3 null 6. Re3 null 7. Nf3 null 8. h4 null 9. Nh2 null 10. Ng4 null 11. Rhh3 null 12. Rhf3 null 13. Nc3 null 14. Ne4 null 15. g3

After Black makes any move, it is a forced checkmate according Houdini. The best move is ’15... f6.’ It allows for mate in 10 moves.


FIDE tournament rules: Is a player allowed to scribble notes on the scoresheet while the game is in progress? Do FIDE rules allow a player to make notes on the scoresheet like

  Here, I wanted to play c4, but thought it would be better to play d4
  first.

  He played Nc6. I think he should have played Nbd7.

No. Notes could help you during the game, and therefore they aren't allowed. The Laws of Chess say:

12.3.a During play the players are forbidden to make use of any notes, sources of information or advice, or analyse on another chessboard
[...]
12.4 The scoresheet shall be used only for recording the moves, the times of the clocks, the offers of a draw, and matters relating to a claim and other relevant data.


Are there any inherent problems with point-symmetric random chess? The regular setup of chess is mirror-symmetric: If you mirror the positions of all figures on the equator of the board (between the fourth and fifth rank) and swap the colours, nothing changes. It is also almost point-symmetric or rotational-symmetric: If you reflect the positions on the centre of the board (or equivalently rotate the board by 180°) and swap the colours, only kings and queens will swap their positions.
By contrast, in Chess 960 a.k.a. Fisher random chess, opening positions are mirror-symmetric by construction, but in general far from point-symmetric. Now, suppose I want to introduce a Chess 096, where white’s setup is determined like in Chess 960, but black’s setup point-mirrors white’s. Castling rules would be point-symmetric as well. A possible starting position would be this:
rnnkbqrb/pppppppp/8/8/8/8/PPPPPPPP/BRQBKNNR w KQkq - 0 1

Like in regular Chess or Chess 960, the only imbalance is that white has the first move – unlike for example, if white and black’s starting positions were randomised independently. My question is: Are there any inherent gameplay problems with these point-symmetric starting conditions? For example, does this tilt the balance of the game?

Consider the following initial position:
[FEN "rkqnnbbr/pppppppp/8/8/8/8/PPPPPPPP/RBBNNQKR w - - 0 1"]

By putting the kings on opposite sides of the board, you've more or less introduced an opposite-side-castling situation, without anyone having castled.
Let's say White starts throwing his queenside pawns forward towards Black's king. In this position, this can be done without compromising his own king's safety, as it's on the other side of the board. What are Black's responses?

Launch his own attack by throwing pawns towards White's king. But given the symmetrical nature of the position, it seems inevitable that White's attack will hit first.

Castle long, to the side White's king is on. This runs into several difficulties. There are a lot of pieces in the way - there's no real way to do so before move nine. Black will have to move two pawns on the "long" side to get his bishops out, which may weaken his castled position, while White technically wouldn't have to move any pawns to castle over there (and White's king is already "there" even if he doesn't castle at all.) Also, if we're going to keep symmetry, Black's king should end up on the f-file (it's a long castle, after all) while White's will be on the g-file.

Leave his king over there, and defend. This may work, although it doesn't seem ideal.

Also note that the queenside attack doesn't have to start on move 1; it can be delayed a few moves to establish a center first.
Overall, it seems to me that this variation may increase White's advantage, especially in scenarios like this example where the kings are very far apart.


Carlsen - Anand, game 6 WCC 2014 -> why Black didn't play 10...Ne4 to try to equalize? What is wrong with 10...Ne4 instead of 10...Nd7?

It seems to me that it was a better move -> Black exchanges one more piece which relieves his cramped position and he obtains the bishop pair.

Can someone explain why 10...Ne4 is inferior to 10...Nd7?

Here is the position I am talking about:

[White "Carlsen, Magnus"]
[Black "Anand, Vishwanathan"]
[Event "WCC 2014"]
[StartFlipped "0"]
[fen "r1bk3r/1p3ppp/p1p1pn2/4P3/1bP5/2N5/PP3PPP/R1B1KB1R b KQ - 0 1 "]

1...Ne4

10...Ne4 doesn't help Black preserve the bishop pair. After the surprising move 11.a3!, Black is forced to take the knight on c3 with the bishop and then we reach a position similar to the one in the game, except that Black's knight is on a more vulnerable e4 square than on a safe square like d7. The pawn on c3 cannot be captured without a significant positional loss to Black.

   [FEN "r1bk3r/1p3ppp/p1p1pn2/8/1bP1P3/2N5/PP3PPP/R1B1KB1R w KQ - 0 10"]
   [White "Carlsen"]
   [Black "Anand"]

   1. e5 Ne4 2. a3! Bxc3+ (2... Nxc3?? 3. axb4 Ne4 4. f3! +-) (2... Ba5 3. b4 Nxc3
   4. bxa5+=) 3. bxc3 Kc7 (3... Nxc3? 4. a4! Ne4 5. Be3 f6 6. Bd3 Ng5 7. O-O
   Nf7 8. exf6 gxf6 9. f4 +=) 4. Be3 b6 5. Bd3 Nc5 6. Bxc5 bxc5 7. O-O-O+=


What are basic openings I need for black? I'm an amateur player and want to learn a couple openings for black. I want to have a response for d4 and e4. I want one for each and hopefully one that is relatively straight forward (unlike Indian defense as I understand). It would be great if they were slightly obscure and therefore unknown to my opponents.
As white I'm basically going to try and play Scotch opening (and maybe later some other e4 openings) every time.

Since you want obscure openings, I would advise the Dutch defense against 1.d4 and the French defense for 1.e4. The Dutch is played less than Indians, queen pawn, Nimzo, Gruenfield, Slav..., thus your opponents won't know anything about it but you will. The Leningrad Dutch and Stonewall defense are played time to time. Nakamura has played the Leningrad Dutch numerous times, Magnus, Levon, Anand, etc have used the Dutch from time to time. I recommend the French because I think it is much easier to learn than 1.e5, which falls to a lot of traps and 1.c5, which is of course not obscure and has a lot of theory. Unfortunately, people can go into a very drawish line in the exchange French. You might want to consider Owen's defense 1... b6.


What is the value of most starting positions in dobutsu shogi? In dobutsu shogi, the usual starting position is a trébuchet or full-point mutual zugzwang position, but other likely (starting) positions can have a completely different value.

If we arrange the pieces in a different way but still mostly on the back rank and mostly on the board, are most of those positions also trébuchets or do they share another commonality?

The first surprise is that if we change the starting position to have mirror symmetry (like western chess) instead of rotational symmetry (like Japanese chess) we get a drawn position in which any lion move is losing.

1. setup S/elg/-c-/-C-/ELG/
1. show board
  ABC
 +---+
1|elg|
2| c |
3| C |
4|ELG| *
 +---+
1. show lines
Cb3xb2 : 0     (50.00%)
Gc4-c3 : 0     (50.00%)
Lb4-c3 : #-46  ( 0.00%)
Lb4-a3 : #-46  ( 0.00%)

Giraffes and elephants are freely exchanged in winning lines, so they must be very close in value. Still, elephants (like bishops in western chess) suffer from being restricted to half of the squares, which probably explains that giraffes versus elephants is a win for the giraffes.

1. setup S/ele/-c-/-C-/GLG/
1. show board
  ABC
 +---+
1|ele|
2| c |
3| C |
4|GLG| *
 +---+
1. show lines
Lb4-c3 : #25   (50.00%)
Lb4-a3 : #25   (50.00%)
Cb3xb2 : #53   ( 0.00%)
Gc4-c3 : #53   ( 0.00%)
Ga4-a3 : #53   ( 0.00%)
1. setup S/glg/-c-/-C-/ELE/
1. show board
  ABC
 +---+
1|glg|
2| c |
3| C |
4|ELE| *
 +---+
1. show lines
Lb4-c3 : #-32  (50.00%)
Lb4-a3 : #-32  (50.00%)
Cb3xb2 : #-24  ( 0.00%)

Or is it?

1. setup S/lee/-c-/-C-/GGL/
1. show board
  ABC
 +---+
1|lee|
2| c |
3| C |
4|GGL| *
 +---+
1. show lines
Ga4-a3 : 0     (50.00%)
Lc4-c3 : 0     (50.00%)
Cb3xb2 : #-62  ( 0.00%)
1. setup S/eel/-c-/-C-/GGL/
1. show board
  ABC
 +---+
1|eel|
2| c |
3| C |
4|GGL| *
 +---+
1. show lines
Ga4-a3 : 0     (50.00%)
Lc4-c3 : 0     (50.00%)
Cb3xb2 : #-58  ( 0.00%)

Starting giraffes draw, but beware of chick fights...

1. setup S/lgg/-c-/-C-/EEL/
1. show board
  ABC
 +---+
1|lgg|
2| c |
3| C |
4|EEL| *
 +---+
1. show lines
Cb3xb2 : 0     (33.33%)
Eb4-c3 : 0     (33.33%)
Eb4-a3 : 0     (33.33%)
Lc4-c3 : #-48  ( 0.00%)
1. setup S/ggl/-c-/-C-/EEL/
1. show board
  ABC
 +---+
1|ggl|
2| c |
3| C |
4|EEL| *
 +---+
1. show lines
Cb3xb2 : 0     (33.33%)
Eb4-c3 : 0     (33.33%)
Eb4-a3 : 0     (33.33%)
Lc4-c3 : #-50  ( 0.00%)

...and starting elephants also draw, but beware of lion moves.

What about side lions in the standard position?

1. setup S/lge/-c-/-C-/EGL/
1. show board
  ABC
 +---+
1|lge|
2| c |
3| C |
4|EGL| *
 +---+
1. show lines
Cb3xb2 : 0     (50.00%)
Lc4-c3 : 0     (50.00%)
1. setup S/egl/-c-/-C-/EGL/
1. show board
  ABC
 +---+
1|egl|
2| c |
3| C |
4|EGL| *
 +---+
1. show lines
Cb3xb2 : 0     (50.00%)
Lc4-c3 : 0     (50.00%)

Central giraffe with lion to the side is a draw.

1. setup S/leg/-c-/-C-/GEL/
1. show board
  ABC
 +---+
1|leg|
2| c |
3| C |
4|GEL| *
 +---+
1. show lines
Eb4-a3 : #65   (100.00%)
Cb3xb2 : 0     ( 0.00%)
Ga4-a3 : 0     ( 0.00%)
Eb4-c3 : 0     ( 0.00%)
Lc4-c3 : #-44  ( 0.00%)
1. setup S/gel/-c-/-C-/GEL/
1. show board
  ABC
 +---+
1|gel|
2| c |
3| C |
4|GEL| *
 +---+
1. show lines
Cb3xb2 : #51   (99.94%)
Eb4-c3 : #65   ( 0.06%)
Ga4-a3 : 0     ( 0.00%)
Eb4-a3 : #-64  ( 0.00%)
Lc4-c3 : #-52  ( 0.00%)

It is a win if the elephant is in the middle. Notice that moving the elephant towards the enemy lion is winning in both positions and moving the lion forward is losing, but in the mirror-symmetric case, chick fight is also winning and elephant towards the other side is losing. At least in this case shogi is more drawish than western chess!

In summary, it seems that trébuchets are quite rare (we did not find any), and most starting positions are draws with the occasional win for the starting player or loss for positions with an obvious weakness.


Hypermodernism definition What are the features of hypermodernism? I know that one feature is controlling the center indirectly (f.ex. fianchetto), and letting the opponent control it with pawns. But I am not sure if there are other features. Nimzowitsch, who was the inventer of the hypermodernism style, wrote several new ideas in his book , such as overprotection, prophylaxis, rook on the seventh rank, knight outposts an so on. Are these ideas also considered as a part of the hypermodern style or is there a clear definition on this?

It seems to me you have the idea spot on already. Traditionally, chess theory was that the best way to control the center was to occupy it. Some players (like Nimzowitsch and others) showed that this was not necessarily true and that there is merit in letting your opponent occupy it while you undermine it from a distance.

I'm not sure if the idea was really novel at the time, but it became popular and as we do whenever we see a pattern we have to name it.

Beyond that I doubt there is much to learn from "hypermodernism" (which is not to say that there is not much to learn from the various rich and deep ideas behind each of the so labelled openings themselves).


How to castle two times in a game A simple question: Assuming that I'm playing as White, how can I castle twice in a game?

I've asked myself this question after seeing the following game from Tim Krabbe's chess records "Greatest number of castlings", in which White castles twice.

[Title "Heidenfeld - Kerins, Dublin 1973"]
[FEN ""]

1. e4 e6 2. d4 d5 3. Be3 Nf6 4. e5 Nfd7 5. f4 c5 6. c3 Nc6 7. Nf3 Qb6 8. Qd2 c4 9. Be2 Na5 10. O-O f5 11. Ng5 Be7 12. g4 Bxg5 13. fxg5 Nf8 14. gxf5 exf5 15. Bf3 Be6 16. Qg2 O-O-O 17. Na3 Ng6 18. Qd2 f4 19. Bf2 Bh3 20. Rfb1 Bf5 21. Nc2 h6 22. gxh6 Rxh6 23. Nb4 Qe6 24. Qe2 Ne7 25. b3 Qg6+ 26. Kf1 Bxb1 27. bxc4 dxc4 28. Qb2 Bd3+ 29. Ke1 Be4 30. Qe2 Bxf3 31. Qxf3 Rxh2 32. d5 Qf5 33.O-O-O Rh3 34.Qe2 Rxc3+ 35.Kb2 Rh3 36.d6 Nec6 37.Nxc6 Nxc6 38.e6 Qe5+ 39.Qxe5 Nxe5 40.d7+ Nxd7 0-1

The answer is plain and simple: You cannot castle twice without breaking the rules. The only chance for this thing to happen is that the illegal move (the second castling) stays unnoticed until the game is ended with an accepted outcome.


When does a chess clock start? Lichess.org starts the clock of each player after their first move.
Chess.com  starts the clock when the players agree to a match, before
their first move.

I think Lichess is correct, that's what we do where I play. What's the rule?

According to the FIDE rules,

  6.6 At the time determined for the start of the game White’s clock is started.

In over the board chess, it's usually Black who does this (you can't have an arbiter start all clocks simultaneously) after the players shake hands and wish each other good luck. If White isn't present, Black may start the clock anyway at the designated time; if Black isn't present, White should start his/her own clock, make a move and press their side of the clock to start Black's. (Of course, in some events, failing to show up at the designated start time constitutes an immediate loss anyway.)

So actually chess.com's method is closer to the official rules, though those games are of course not regulated by the FIDE rules.


Query for games where the difference of player ratings was big I want  to run a query on a chess games collection which would give me games played by strong players vs weak players, let's say games from the first round of Open tournaments (Swiss system) where grandmasters face amateurs, so basically a query for games where rating difference is bigger than x.

What tools would you suggest? what method?

If you have access to a Chess Query Language tool you can use that, albeit I'm not familiar with it. SCID is free and more easily available : http://scid.sourceforge.net/

1)Open your pgn file

2)Search header rating differences white - black = 200 - 40000


Why do top GM's "retire" from chess? After Kramnik's recent announcement, Nakamura also said in a chess.com interview that he will retire from chess at age 40.

I am curious why a super GM feels the need to "officially retire" from chess (or a format of chess). Why not just stop playing but keep the door open for future events? Who knows, maybe you'll feel different after a break.

To be clear, I am not asking for speculations specific to Kramnik or Naka's mindset. I want to know what concrete, practical reasons there may be for a top GM to announce retirement, like sponsorship or contractual reasons as an example.

Update based on comments and whoever voted to close: I'm specifically not asking for guesses or opinions, but for insight from someone who have knowledge of a super GM's unique situation (be it legal, social, practical or otherwise) to elaborate why it is beneficial to announce retirement rather than simply stop playing.

I don't know about the practical reasons that you suggest, but I imagine retirement is a way to tell your fans and the world "stop bugging me!". :-) Super-GMs probably retire when they feel they are past their peak and would rather retire at the top of their game than have the world see them decline.

That said, retirement is not irreversible! For example look at Kasparov, who "retired" in 2005 and yet has reappeared in tournaments from time to time: https://en.wikipedia.org/wiki/Garry_Kasparov#Retirement_from_chess.


Is there a reason AlphaZero hasn't been allowed to learn for longer? Why don't the developers of AlphaZero let it learn for days, or even months on end? Wouldn't its neural network become much stronger, at the cost of just occupying some computational resources for a while? It seems like this would make it indisputably the best engine in world, since right now there's still controversy on whether it's clearly better than Stockfish.

If something like this already is happening, please correct me.

Check out the AlphaZero paper, figure 1.

As you can see from the leftmost figure, you can let AlphaZero train, but that doesn't mean it'll improve. In fact, AlphaZero peaked at a level slightly above Stockfish 8 (in other words, it'll likely lose to Stockfish 10).

I'm no expert, but I understand Leela is competitive with Stockfish 10 not because she has trained for longer, but because she's doing certain things that AlphaZero didn't do (such as "squeeze excitation" as in the latest Test 40).


Machine Learning parameters for human vs computer detection I would like to start a machine learning project that should recognize whether a player is a person or a computer.
I have a data set with labeled labels (computer or human).
In your opinion, what would be good input parameters?
I would like to also include use the chess position and the move. But which coding would be appropriate?
Other parameters would be some positional and material evaluation values and the centipawn loss

Coming from a machine learning background, although this sounds like a supervised learning task, do not expect any decent results.
Most players today use the computer to analyze positions and prepare quite deep with the engines. So the distinction there is lost in most medium to high level game play.
Also, simply knowing whether a game was played by a computer or not is not sufficient. To train any model, you need to have an intuitive understanding of your data. In this case, simply the sequence of moves played is not sufficient.
But if you're still bent on trying your hand at this, you could look into sequence classification using LSTM networks using an encoded matrix as inputs, but I don't see it working very well at all. If a human can't tell the difference, any model you develop won't be able to either.


Is triple check possible? In my logic, triple check not possible. Because I assume there is a move with two pieces at once needed. The only move I know is castling. The King can not give a check.
So is triple check impossible?

Triple check is impossible, unless you want to count an x-ray attack as the third check.  A queen and rook attacking on the same file is normally thought to be one check.


How are online chess engines' architecture designed? I recently build a chess engine using javascript (https://github.com/Ram-the-coder/ai-chess-engine-v2). It runs on the browser - because of this when the chess engine is computing the best move, the webpage gets unresponsive. So I thought if I move the processing to the server, then I can eliminate the unresponsiveness. But if I do that then I've to maintain the game state for each client of the server. The size of the game state I think is in mega bytes as it includes the hash tables.

Another problem I faced in keeping the processing on the client-side is that the processing speed becomes dependent on the client's device.

How are such online chess engines usually built?

I don't think storing the game state in memory is good as the server has to serve many clients. Maybe storing in a database in the same server might work...

If I use a client-server architecture, won't I be restricted to serve one client request per server at a time? If yes, how are online chess engines able to serve unlimited clients at the same time?

Lichess uses WebAssembly (Wasm) - as is stated on the analysis page (“Stockfish 10+ WASM in local browser”). Wasm is the obvious thing to use, as it runs on the client side but is faster than JavaScript.

Running Stockfish in a web browser is usually done using Niklas Fiekas’ Wasm+JavaScript port of Stockfish, which is what Lichess uses. This consists of a Wasm file stockfish.wasm containing the engine itself, and a smaller JavaScript file stockfish.wasm.js that controls the use of the engine. (There is also a large file stockfish.js that is used as a fallback on browsers that lack native Wasm support.)


Sicilian Defence, Dragon Variation [FEN ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 O-O 8. Qd2 Nc6 9. O-O-O d5 10. exd5 Nxd5 11. Nxc6 bxc6 12. Bd4

What is White's plan & idea behind 12. Bd4 move?

Something that instantly stands out to me is that 12. Bd4 challenges black's strong fiancettoed bishop.

Black must submit to trading pieces or weaken his bishop.

Also,12. Bd4 removes pressure from the c3 knight. This piece is in a bit of a weak position, especially since one of its defenders is a pawn next to the king that we don't really want to move, and definitely don't want to double up.

Finally, 12. Bd4 could help white control the d-file. Black's queen could step out of the way much more easily and allow the d1 rook to push the d8 queen off of the open d-file. (For example: Knight takes knight, queen takes knight, bishop takes bishop, rook takes bishop.) The queen is also free-er to move along the "up-and-to-the-right" diagonal.

Regarding other future ideas:

A move like Bc4 might be in order soon: it develops a piece, unites the back-rank rooks, attacks a strong but weakly-defended piece, and has the chance to participate in a kingside attack, eventually. It also protects the hanging a2 pawn.