Which chess player has the most openings named after him? I always thought it was interesting that chess players had openings named after them.  The game of chess has only been popular and organized for about 150 years, yet all the most popular openings and most of their sub-variations have already been named, many after players from the 19th or early 20th centuries.  In five hundred years, will all these basic openings still be named after Morphy, Steinitz, Capablanca, and Lasker?  But I digress.

Which player has had the most openings or opening variations named after him?  My guesses would be Botvinnik or Aljechin (Alekhine).

Nimzovitch.

NimzoIndian Defense: 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4
Nimzovitch Defense: 1.e4 Nc6
Nimzovitch Attack: 1.Nf3 d5  2.b3 (1.b3 is the Nimzo-Larsen Attack)

Nimzovitch Variations:

Sicilian Defense: 1.e4 c5 2.Nf3 Nf6
Queens Indian Defense: 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Ba6
Falkbeer Counter-Gambit: 1.e4 e5 2.f4 d5 3.de5 c6
Falkbeer Counter-Gambit: 1.e4 e5 2.f4 d5 3.de5 c6 4.e4 Bb5+ *
Nimzovitch QP Defense: 1.d4 Nf6 (most sources attribute it to Bogoljubow)
Latvian Counter-Gambit: 1. e4 e5 2. Nf3 f5 3. Nxe5 Qf6 4. d4 d6 5. Nc4 fxe4 6. Ne3
Philidors Defense: 1. e4 e5 2. Nf3 d6 3. d4 Nf6
French Defense, Advance Var-Nimzovitch Var: 1. e4 e6 2. d4 d5 3. e5 c5 4. Qg4
French Defense, Nimzovitch (or Winawer) Var: 1. e4 e6 2. d4 d5 3. Nc3 Bb4
Four Kts Opening, Nimzovitch or Paulsen Var: 1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bb4 5. O-O O-O 6. Bxc6
English Opening, Nimzovitch Var: 1.c4 e5 2.Nf3
Benoni Defense, Nimzovitch or Kts Tour Var: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. Nf3 g6 7. Nd2
Caro-Kann Defense, Nimzovitch or Tartakower Var: 1.e4 c6 2.d4 d5 3.Nc3 de4 4.Ne4 Nf6 5.Nf6+ ef6
Ruy Lopez, Steinitz Var - Nimzovitch Attack: 1. e4 e5 2. Nf3 Nc6 3. Bb5 d6 4. d4 Bd7 5. Nc3 Nf6 6. Bxc6
English Opening - Four Kts Var - Nimzovitch Var: 1. c4 e5 2. Nc3 Nc6 3. Nf3 Nf6 4. e4
EO - Nimzo-English Opening: 1. c4 Nf6 2. Nc3 e6 3. Nf3 Bb4

Notes: Simon Winawer played the "Winawer Variation" of the French Defense once in his entire career; why it's named after him instead of Nimzovitch who really popularized it is a mystery (to me at least). And no, Winawer does not deserve the credit for playing it first (if he even did that) many openings are named after the masters who hammered out the theory of them and/or made them popular. Ergo the "Advance Variation" of the French Defense should also be named after Nimzovitch!

SOURCES: "The Oxford Companion To Chess" by David Hooper & Kenneth Whyld, 1984; p 226
http://www.chessvideos.tv/chess-opening-database/search/Nimzovich-variation
http://www.365chess.com/eco/C62_Ruy_Lopez_old_Steinitz_defence_Nimzovich_attack


Morozevich variant in the Tarrasch french I am confused with the Morozevich variant. I've seen quite a few funny games where they played ...g5, which gives very interesting moves, but I'm surprissed at not having seen any game in which white plays 4.e5, which seems a natural move, blocking the classical square f6 for the king-side knight. Here, What is the main idea of the Morozevich variation in the French vs. the Tarrasch?, Nh6 was proposed in a comment, but I think after Bd3,c5,Ndf3, the black knight is quite weak.  How would you play against 4.e5?

I don't think Black is in a hurry to develop the knight.  4...c5 is the main move.  If White plays Qg4 the bishop goes back to f8.  As a matter of fact the bishop sometimes goes back to f8 even if White doesn't play Qg4.

Of course Nh6 is fine and the knight will then go to f5 where it is happy.

Note:  1. There are other lines where the Bishop returns to f8, like 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 b6 5.Qg4 Bf8.
2. In non-Nf6 lines it is common for the knight to head to f5 via e7 or h6


Piece And Pawn Only Massacre Games What are the fastest possible games in which only all pieces and all pawns are captured? I did some searching myself.
Pieces Only
[Title "me, chess.stackexchange.com 3/2/2019, Non-Unique Proof Game In 13.5 Moves"]
[FEN ""]

1. e4 e5 2. d3 d5 3. Qg4 Qg5 4. Qxc8+ Ke7 5. Qxb8 Qxc1+ 6. Ke2 Qxb1 7. Qxa8 Qxa1 8. Qxf8+ Kd7 9. Qxg8 Qxf1+ 10. Kd2 Qxg1 11. Qxh8 Qxh1 12. Qe8+ Kxe8 13. d4 Qe1+ 14. Kxe1

Pawns Only
[Title "me, chess.stackexchange.com 3/2/2019, Non-Unique Proof Game In 16.0 Moves"]
[FEN ""]

1. e4 e5 2. f4 f5 3. g4 g5 4. h4 h5 5. d4 d5 6. c4 c5 7. b4 b5 8. a4 a5 9. bxa5  bxa4 10. cxd5 cxd4 11. exf5 exf4 12. gxh5 gxh4 13. Rxh4 Rxh5 14. Rxa4 Rxa5 15.  Rxd4 Rxd5 16. Rhxf4 Rhxf5

In the pawns only, you don't need to move so many pawns.  Getting the major pieces involved early seems to be fastest:

[FEN ""]

1.e4 c5 2.Qh5 Qa5 3.Qxh7 Qxa2 4.Qxg7 Qxb2 5.Rxa7 Rxh2 6.Rxb7 Rxg2 7.Rxd7 Rxf2 8.Rxe7+ Kd8 9.Qxf7 Rxd2 10.Qf5 Qxc2 11.Qxc5 Qxe4+  *

I was unable to find a faster version of the piece only.


Why does stockfish suggest bishop pins on knights early on? Stockfish suggests the following pin for me (white) against the queen on the night. However, whenever I play this move in real games black just kicks the bishop off with pawn to h6. I end up just wasting moves? Am I supposed to pin and then take? What is the point of that?

In this particular position, it's not so much that the pin is anything special; there simply aren't many squares where you can put your bishop that don't let your opponent double your pawns. The only other option would be Bxd6, which gives your opponent the pleasant choice of either developing their queen for free with Qxd6 or opting for controlling some central space with cxd6.
In this case, yes, you would take if they play h6, since retreating would again lead to Black doubling your pawns.
Note that your choice of Nxe5 also allows your opponent to double your pawns after ...Bxe5 Bxe5 Nxe5 dxe5.


How would you analyze this critical position from my most recent game? r1b2r2/1p2bp1k/p3p2p/2qnN3/2B4Q/2P3R1/PP3PPP/2K1R3 w - - 4 20

In the diagram position, I was white.  I had sacrificed a bishop for a pawn for a huge attack on the black king.  I realized during the game that this was a critical position and spent 40 minutes trying to make the tactics work, but I ran low on time and ended up failing at the task.

How should one go about analyzing this position to come up with the right move?  Try to think about the position on your own before checking with an engine.

These positions are good for a robotic approach, which is my favourite. I would try to come with candidate moves.

First I would try to eliminate quickly (or find miracles in) Qxh6+ and Rg7+
Then I would go for two more obvious checks, Bd3+ and Qe4+. I would try to get as much feeling about what's going on in these lines, find their problems to have chance to find (if necessary) some hidden properties of position (like Bd3+ is almost mate if we prevent black piece to go on f5.
Then I would go for mate threats, trying to quickly eliminate Rg6. From point 2 I should already know that Nxf7 might be a mate threat, even if I can miss this for now and come with the move later during capture searches.
I would go for captures and light threats, trying quickly to eliminate nonsense again. Probably here would be Qxe7, Rg8 and of course Nxf7, if not in the previous point. I guess Ng4 could stay hidden from my sight forever as the move came to my mind after writing the whole post. Engines wouldn't make such a mistake :-)

Depending on what would come from this search, which I think shouldn't take more than 5 minutes, I would try to sort candidates from the one I like the most. Well, Nxf7 is a big and obvious candidate. It threatens mate and after Rxf7 it is not even a sacrifice. So I would go for it, unless I would have even better feelings about checking lines Bd3+ or Qe4+. That is possible, as I would have already solid cover of these now. Ok, calculating Nxf7 is another story, you will do similar work like here. Find opponent's candidates, being careful, as your queen is hanging and you are a piece down. When I know only Rxf7 is serious, then I would go for Bd3+ and Qe4+ as a huge candidates. If I find some problem there, I would try to come with other candidates like Qg4. You probably don't search for all weird candidates in later moves of calculation, as your head could explode by doing that. That is a reason why we sometimes miss nice combinations. Always checks, mate threats and big captures and threats first in start position and then later, the less candidates.

In my answer to this question you can see the most brutal combination I could have in my game, but wasn't found during the game either by me, or by my opponent. Was cool to hear how lucky I am, as the computer saw it immediately. You look for calm moves in the beginning, but find the 4th calm move in a row in such a firefight!


Is holding the opponent's captured pieces legal or allowed? There was a controversial finish in a Canadian championship, where an opponent [un]knowingly held the queen of the other player. The [victimised] player wanted to promote his pawn to queen, but couldn't find it. Due to time pressure, he used an upside down rook instead of a queen.
The arbiter didn't allow this and the player ended up losing the game. The decision was not reversed even though there was a video evidence of the event.
In many chess videos, I see that even the great world champion Magnus Carlsen holds the opponent's pieces in his hands, of course without any ill intent.
Is there any rule or guideline for this?

The first thing to note is that even if the opponent is deliberately hiding your captured queen (or any other piece you might want to promote to) there is no excuse for using some substitute because the rules allow for a simple solution: stop the clock, call the arbiter and ask for the piece you require. It is part of the arbiter's job to do this.
Holding a captured piece or pawn is perfectly legal as long as it does not distract or disturb the opponent. Some players like to hold a captured piece between thumb and finger and spin it.
Gelfand is famous for doing this. He always does it under the table so that the opponent doesn't see it and so cannot be disturbed by it. If your opponent does this where you can see it and the movement disturbs you then you are within your rights to call the arbiter and complain.


When you check someone, do you have to say "check"? Yesterday I was playing with a friend, I was almost out of time, he checked me, didn't say anything, I didn't see the check as i was in a hurry to make my move. And I was mated.

Computers don't let you play any move when you're in check. Therefore in reality, are you allowed to make a move when you're in check? or you cannot make any move? I mean should you undo any move that you do by mistake or not? And should your opponent warn you about being checked or not?

In a tournament game, you are not supposed to speak at all other than to offer a draw or adjust a piece. This includes saying check. This tends to seep into casual games among more experienced players (I haven't said check in years).

For players that do not compete in tournaments at all, I don't think that there is any obligation to point it out.

When your opponent makes an illegal move, though, as it sounds like you did after missing the check, it has to be pointed out. You can't just follow it up with a mate immediately. In blitz, making an illegal move means a loss. In a longer game, a minor time adjustment.


Why did black resign in this game? Watching this video, it seemed after the highlighted point in the video that black was doomed, but from my view it was just materiel?  After the exchange, white would have taken a rook and the queen (and trading white's own queen) leaving black only a bishop vs. two white rooks.  Is that why black resigned?  Obviously at that point black would have been at a big disadvantage.  But I'm curious if there was a compelling mate opportunity for white above and beyond the materiel advantage.  Here's the video:

https://youtu.be/APJ5E1wXB3g?t=1631

(Also, I'm confused why the YouTube video refers to this as a "Queen sacrifice" since the queen wasn't in fact sacrificed?)

Because he is losing the Rh8, and at that level, that is an EASY win. It is also worse than that as mate is coming in a few moves. Even without the almost immediate mate, being down a pawn and an exchange is a lot of material.

By the way, although black did not take it, white did offer a queen sac on move 24.Qg7, but had it been taken, a new queen would have appeared next move.

 [FEN "2q4r/2rbkp2/4pQpP/pp4P1/4P3/5P2/PPPR4/2K4R b - - 0 1"]

 1... Kf8 2. Qxh8+ Ke7 3. Qf6+ Kf8 4. h7 {And mate after a couple of spite checks on c2.}

Here is the full game:

 [Event "EU-ch rapid"]
 [Site "Tallinn"]
 [Date "2019.12.05"]
 [Round "1"]
 [White "Aizenberg, Benny"]
 [Black "Guseinov, Gadir"]
 [Result "1-0"]
 [ECO "B77"]
 [WhiteElo "1995"]
 [BlackElo "2691"]
 [PlyCount "55"]
 [EventDate "2019.12.05"]
 [EventType "swiss"]
 [EventRounds "13"]
 [EventCountry "EST"]
 [FEN ""]

 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Be3 Nf6 6. Nc3 Bg7 7. Bc4 O-O 8. Bb3 d6 9. f3 Bd7 10. Qd2 Nxd4 11. Bxd4 b5 12. h4 a5 13. Nd5 Nxd5 14. Bxg7 Kxg7 15. Bxd5 Rc8 16. h5 Rh8 17. O-O-O Qb6 18. g4 e6 19. h6+ Kf8 20. Bb7 Qxb7 21. Qxd6+ Ke8 22. Qd4 Rg8 23. Rd2 Rc7 24. Qg7 Rf8 25. Qxh7 Ke7 26. Qg7 Qc8 27. g5 Rh8 28. Qf6+ 1-0


Adjusting to longer time controls I've played extensively online with a G/30 time control, and OTB at G/30 with a 5 second delay.  I'd like to start playing in tournaments though that have a time control of G/90 with a 30 second increment.

Should I approach the game any differently?  Obviously, I'd have longer to calculate, but are there any other types of differences to be aware of?  Or, are there different ways to prepare mentally?

I feel like the 90-minute (+ 30s increment) games are just perfect for getting better, but it might be caused by the fact that I'm used to it. Pretty much any longer time control will do the job.

But definitely, your choice to play with longer time controls is a good one. For me, a 30-minute game is a rapid game and even FIDE thinks so :)

  A ‘Rapidplay’ game is one where either all the moves must be completed in a fixed time of more than 10 minutes but less than 60 minutes for each player; or the time allotted plus 60 times any increment is of more than 10 minutes but less than 60 minutes for each player.

The big difference will obviously be the "redundant" time for you. I think you can use that for improving in some techniques like double-checking and evaluating positions.

The idea is to use these methods extensively (and consciously) until they become part of your unconsciousness. I learned this idea from a book called Pumped Up Your Rating by Axel Smith.

Some other advice:

Your brain can adapt to the time quickly and, especially if you're a "time-trouble player", what might have seemed as a lot of time before is suddenly not that much... That doesn't mean you shouldn't think, just anyway be aware of the time situation on your clock.
Don't be hasty when your opponent starts playing quickly. That applies generally, but in longer time controls it is more important than anywhere else. For example, you have no reason to become nervous when your opponent has 80 minutes left and you have "only" 55 minutes on your clock after 20 moves - it's quite a lot of time. Just stick to your time management.

I guess the last point falls into the category of mental preparation because you might feel pressure in such a case. So it's good to be prepared for that.

The last thing I have on my mind is how you spend the time when it's your opponent's turn. In rapid games, players are usually used to sit at the board throughout the entire game, which is almost impossible in case of long games.

It usually depends on the character of the player, some stand up from the games very often, some not. Just keep in mind that you shouldn't distract yourself too much when you're off the board as you don't want to build your concentration from the bottom-up again. I think you will have to try this yourself.


How to detect invalid pawn structures (not based on opponent material) for FEN valdation? I'm going to further expand a FEN validation function I have been working on for some time to include illegal pawn formations such that:

  ... for example white pawns could
  never be on a2, a3, and b2; there is no way a pawn could be on both a3
  and b2. (source)

This particular test doesn't require to take opponent missing material into consideration (it could, but I have that on a separate test to check every column with multiple pawns and determine the minimum missing material the opponent should have, but that test is different, I only want to focus on this other test assuming infinite material can be used to reach those positions).

So far, my approach has been to draw a triangle from any pawn (excluding the ones that sit on the starting rank, which wouldn't allow a triangle to be drawn) all the way to the starting rank, then counting all the pawns that would fit on the base line of the triangle (starting rank). In the case the triangle goes out of bounds, those pawns are not counted:

That amount of pawns on the bottom of the triangle are the upper exclusive limit that pawns could then appear anywhere inside the triangle (because the test is applied to each pawn and each one will draw their own triangles and because the test is a generalized "no invalid pawn structures?", as in, all or nothing, it is safe to give big triangles with cluttered pawns a pass, since later on, the pawns inside will undergo the same test).

Example from the left image with limit of 3, there should be 0-2 to be a legal pawn structure.

Will this solution always work or there are times where this limit will be incorrectly generated? Can this be simplified further using a different reasoning or methods?

Any ideas, feedback, alternative solutions are appreciated.

There is at least one case where your method will fail: pawns on f2, g3, h2 and  h3.

The structure is illegal, but drawing triangles from every pawn will not show this. To catch this, you'd have to draw the triangle from every square of the chessboard (h4 in this case demonstrates the illegality).

So as you said, draw triangles, but instead of starting from pawns, draw them from every square on the board. (For white, it actually suffices to try every square from the 3rd to the 8th rank.)


How does strategy change in the infinite variant of chess? I've recently become interested in infinite chess (this presentation from Joel David Hamkins [updated presentation based on the link provided by JDH in comments; significantly more comprehensive than what was originally linked to] talks a bit about it and some of the interesting mathematical questions). You can find another discussion of the mathematical properties of infinite chess here.

My question is, has this variant been much explored by chess players (as opposed to mathematicians, not that they aren't also chess players)? Are there resources that explain the strategy for infinite chess? Do the principles that guide standard chess play change drastically for the infinite variant, or are they merely extended?

All the normal rules of chess strategy must be completely void. Consider some of the most important ones:

Material advantage helps to win. Mainly because with more material it's easier to queen a pawn (not available in infinite chess) and because it makes it easier to checkmate the other king. But checkmate is much harder anyway (no board edge to help), and in infinite chess you may have a billion extra knights that are of no use to help defend your king because they're a trillion squares over to the left. In general material will still be useful, but I doubt a queen is going to be much better than a rook.
The center. In chess, pieces want to be placed where they influence the most squares, and that's usually the center. In infinite chess, there is no center and no square is inherintly better than any other.
Development. There is no starting position, and no concept of a square that's better than the original square, so no development.
Pawn structure is an artifact of having two rows of 8 pawns at the start, and a center. Without any of that, all the knowledge we have about pawn structure goes out the window. A pawn may advance a billion squares without ever meeting another pawn, or be blocked by a trillion of them.

And so on, and so on.

I think a study of the strategy of infinite chess would have to start with an analysis of which basic mates are possible (queen, rook and king vs king probably mates, two rooks don't, I guess? Definitely a lone queen and king doesn't, needs an edge).

If you have a lot of pieces, you'd think you'd want to move part of them towards the enemy king, keeping some at home to defend the king. But for queens, rooks and bishops, distances are deceptive -- if the lines and diagonals are clear, they can get to wherever they can possibly get in two moves. Pawns, kings and knights are unimaginably useless in comparison.

I wonder if anything is known about games of infinite chess with more than a few pieces.


Human-like engine for endgame training I am doing endgame training with LucasChess (LC), but the problem is not really related to LC, but to chess engines in general.

I have this problem: See picture. When I move  Kh6 in this position, the engine in LC moves Ke8. Probably this is the move with which white needs the most moves until mate.

But it is also the move which makes things easy for white.  It would be harder for white if black would move Kg8, trying to block the pawn until it is no longer possible and maybe provoking a stalemate.
Instead of blocking, black flees in direction  to the center.

I assume the engine sees that with fleeing to the center it is maybe a mate in 20 and without fleeing and trying to block it is maybe a mate in 16. So it makes the "optimal" move with which the distance to mate is the longest.

But this is not the best human like move.  Because it makes it easier for white to queen its pawn. It clears all possibilities for white to make mistakes and in this way it takes away an important part of the training effect.

I have seen this behaviour in nearly all pawn endings, not only this one; and also in other endings.

All engines I've tried show this behaviour.  (Komodo, Stockfish, Gull, Gaviota, Fruit)

So my question is: Do you know a free engine or some settings for an engine which plays endgames human-like, trying to block pawns as long as possible instead of fleeing with the king to the center?

Update: konsolas found an engine (Leela or Lc0) which treats the given position well and so at first I accepted his answer as the answer.
In between I've tested Lc0 more and came to the conclusion that it is absolutely not usable for endgame training, because it plays most endings catastrophically. When accepting the answer, I couldn't even imagine any engine playing endgames so bad.

So I want to clarify my question: Do you know a free engine or some settings for an engine which, with movetime 1s or below, without needing a graphics card, plays endgames human-like, trying to block pawns as long as possible instead of fleeing with the king to the center?

Lc0  with current nets or dkappe's distilled nets do not qualify, because these play most endgames horribly and absolutely non-human-like on a PC without graphics card. And from all what I've read a graphics card even won't help for its endgame play.

Update 2:
I'd like to clarify that it is not only the position above, but a lot of others, too. Engines play the move which makes distance to mate biggest, assuming perfect play of the opponent.  Example 8/8/8/6K1/8/8/3Q2kp/8 b - - 4 9, see second picture.
Engines play  Kf3, which makes it very easy for W.    What B should play is Kg1, and now it's much harder for W to win. W then needs to know or find that he has to allow B to queen.

Alpha-beta engines, in many endgame positions, will quickly find a mate and therefore will pick the move which prolongs the mate for the longest.

Engines which use Monte Carlo Tree Search, however, pick the line with the greatest winning/drawing chances. For example, Lc0, a neural network engine which uses MCTS, suggests Kg8 as you wanted in your position:

8/6k1/6P1/7K/6P1/8/8/8 b - - 0 1

1...Kg8 2.Kh6 Kh8 3.Kg5 Kg7 4.Kf5 Kg8 5.Kf6 Kf8

Lc0 does not play endgames as well as alpha-beta engines, but it tends to play them in a much more human manner.

I would also suggest taking a look at Komodo 12 MCTS, which may also exhibit this type of behaviour.


Why did Smirin resign against Anand in the Blitz semifinal 1994? There is a video on YouTube about how Anand took 1:43 for move four in the Blitz semifinal and ended up winning the match. What I cannot understand is why White resigned because I can not see the checkmate. Can someone explain how checkmate is possible in one or two moves?

Here is a link to their game.

While in the final position, checkmate is still a move or 20 away, it's clear that White is lost. Black is a piece ahead with no compensation for White at all. People resign in such a position already on the higher level of club play. In a normal (i.e. non-blitz) game between grandmasters, White would probably already have resigned by move 30.

[FEN ""]
[White "A. Smirin"]
[Black "V. Anand"]
[Event "New York Intel Active (blitz)"]
[Result "0-1"]
[Date "1994"]
[StartPly "100"]

1. e4 e5 2. Nf3 Nf6 3. d4 Ne4 4. Ne5 d6 5. Nf3 d5 6. Bd3 Nc6 7. O-O Be7 8. c4 Nb4 9. Be2 Be6 10. Nc3 O-O 11. Be3 Bf5 12. Rc1 dxc4 13. Bc4 c6 14. Ne5 Nc3 15. bxc3 Nd5 16. Qb3 f6 17. Qb7 fxe5 18. Qc6 Be4 19. dxe5 Kh8 20. Bd4 Rc8 21. Qa6 Nf4 22. f3 Rc6 23. Qa4 Rc4 24. Qc4 Bd3 25. Qc6 Ne2 26. Kh1 Nd4 27. cxd4 Bf1 28. Rf1 Qd4 29. f4 Qe5 30. g3 Qc5 31. Qe4 Bf6 32. Kg2 Rc8 33. Rf2 Qc6 34. Qc6 Rc6 35. g4 h6 36. Kf3 Rc3 37. Ke4 Kh7 38. Re2 Rc4 39. Kf5 Rc5 40. Ke6 Rc4 41. Rf2 Kg6 42. h3 Rc3 43. Rh2 Rf3 44. f5 Kg5 45. a4 Kh4 46. Kd5 Ra3 47. Kc6 Ra4 48. Kb7 a5 49. Kb6 Ra3 50. Kb5 Rh3


How should I improve my chesstempo tactics rating? I was stuck on a chesstempo tactics rating of around1482-1509 for about 2 days. I reached my current level within 3 days. I want to improve to an 1800+ rating. How can I improve?

You should not obsess with ratings let alone tactics rating on some website. (Specifying your rating to the last digit suggests you do.) It is just a number.

Once you solved a problem. Chesstempo also shows you the tactical motive for this particular problem which is quite useful for learning. Make sure that you can recognize each motive in the solution. If not, learn about this particular motive and do more tactics of that type of motive. It is essential that you take the time to understand the problem with the solution at hand.
Be patient when solving tactics. Don't go for the first good move you see. Consider all of your opponent's options.
Do more tactics, but also mix it with playing regular games and resting time. The goal is to store those motifs subsconsciously and this can only be done by repition.


Why is this a checkmate? I'm new to chess and I'm confused about a puzzle I was practicing.

As you can see my black queen has put the white king in check, but I'm confused how this is possible if a rook is right next to my queen and could capture me next turn. Am I missing something?

To get out of check, the king needs to move to a square that isn't attacked by any opposing pieces, or you need to capture/block attacking pieces such that the king is no longer under attack on its current square.
Since the queen is attacking the king and both of the unblocked squares it can move to, white needs to capture the queen to get out of check here. The only two pieces in position to attempt this are the king and the rook. The king cannot do because it would be attacked by the black rook if it did, and the rook cannot do it since it would expose the king to being attacked by black's dark-squared bishop.
This situation is called pinning: the bishop has "pinned" the rook (even if the queen weren't there) because moving the rook would expose the king to capture, and it is illegal to make a move which places your own king in check. This term is also used when the piece you expose by moving is a high-value piece other than the king (typically a queen or rook), but in this case it's not illegal to make the move, it's just a bad idea most of the time.


Why is Nb5 a strong move here? Why is there a guaranteed material gain? Taken from:

Chess Academy: A subtle blunder

[Title "White to move"]
[FEN "r1bqr1k1/pp1nbpp1/4pn1p/2pp4/2PP1B2/P1NBPN2/1P3PPP/R2Q1RK1 w - - 0 1"]

White can play Nb5 followed by Nc7 but wouldn't Black play Rf8 beforehand?

This is a familiar tactic I often get to use myself in another opening line. If black plays 1... Rf8, then comes 2. Bc7! Qe8 3. Nd6 Bxd6 4. Bxd6 and black loses the exchange anyway.

[Title "White to move"]
[FEN "r1bqr1k1/pp1nbpp1/4pn1p/2pp4/2PP1B2/P1NBPN2/1P3PPP/R2Q1RK1 w - - 0 1"]

1. Nb5 Rf8 2. Bc7! Qe8 3. Nd6 Bxd6 4. Bxd6

Chess is about patterns. Since I was familiar with the pattern, I spotted this tactic immediately.


Aggressive variation against Queen's Gambit Declined? My style favors aggressive, complicated openings. I have constructed a suitable repertoire with White beginning with 1. d4 with one exception. I have so far been unable to find a satisfactory response to

[fen ""]
1. d4 d5 2. c4 e6 3. Nc3 Nf6.

I would prefer not to play the Exchange Variation because it is extremely popular among my regular opponents, but if it is the only option I would consider it. However, this would mean also finding something against the Alatortsev (3... Be7).

Can anyone give me a good suggestion? I'm willing to go into less popular lines if they have been tested by a 2700+ at least once.

Edit: To be clear, I'm already set vs. the Slav/Semi-Slav. I'm purely concerned with situations where Black does not play c6 at some point.

Maybe the 5.Bf4 lines are a good fit. In the 5.Bg5 lines, black can often exchange bishops with the Lasker/Capablance maneuver, involving an early ...Ne4 or ...Nd5 forcing the bishop exchange, and it is hard to get aggressive play against that. 5.Bf4 avoids that, with the drawback that there is less pressure on d5, allowing ...c5 by black. Usually white takes the pawn.

There's an all star list of top players who have used it -- Kasparov, Topalov, Ivanchuk, Kramnik, Gelfand, Korchnoi, et cetera.

I should probably add an example game here but I don't know one from the top of my head and I don't have much time...

A recent book that advocates this line is Burgess' "A Cunning Repertoire for White", which is a generic 1.d4 opening repertoire book.


Is it possible to configure SCID to use English descriptive notation? I'm going through a classic book (Reti's Modern Ideas in Chess), which uses English descriptive notation rather than algebraic notation.  I see there is an online resource which has converted the book to algebraic notation, but is it possible to configure SCID to use English descriptive notation instead of the default?  Links below.

http://www.openchessbooks.org/reti-mic/chapter1/combination.html
https://sourceforge.net/projects/scid/

An example of the book notation is

4. P - Q Kt 4

Which converts to the algebraic notation of

b4

I looked through the help, the menus, and the option file. I didn't see anything that looked like it could do this.

Of course, SCID is open source. If you know programming, you could always add this functionality yourself.


What's up with the doubled pawns? There's another question on this SE, which asks the question in reverse:
What are the reasons why I should not try to take a Knight with my Bishop if it'll result in doubled pawns?

The answers do not adequately address, why you should try and double up your opponents pawns. To be more precise let me point to this Youtube video explaining
the Budapest opening.

[fen "r1bqk2r/pppp1ppp/2n5/4P3/1bP2Bn1/2N2N2/PP2PPPP/R2QKB1R b - - 0 1"]

The Youtuber recommends ...BxNc3 with the sole aim of creating doubled pawns. So why are doubled pawns so awkward? The only reasonable answer on the Wikipedia page I could understand was that the Rooks can't provide support to the leading pawn in a doubled pawn structure. Can someone shed more light?

Isolated double pawns like in your example are considered to be both a static and a dynamic weakness. It is a static weakness since the pawns can no longer defend each other or be defended by other pawns. It is a dynamic weakness since the front pawn is blocking the advance of the pawn behind. It is strategically important for the opposing player to control the square directly in front of the pawns, c5 in your example, thereby cramping the movement of both pawns.

However, doubled pawns are often compensated by other dynamical factors, like open files for the rooks and long diagonals for the bishops.

In the Budapest line you are asking about, the move 6.Nbd2 is more popular (than 6.Nc3), leading to a good position for white by simple means.


Are blitz or bullet games better for improvement? If I have ten minutes’ spare time and want to use it to improve my chess, is my time better spent playing one blitz game or five bullets?
(I’m taking blitz to be 5min each and bullet to be 1min each)
(I’m ~1300 - 1400 rated)

What improves your chess is the time you spend thinking on chess and solving chess problems (either during a game or when doing exercices).

As a consequence, if your concern is to make progress, a 5' blitz is better than five 1' bullets.

What you will play will look more like a real chess game; at 1300-1400 I suppose you seldom drop pieces in blitz, but often in bullet. Also, maybe this will be the occasion to practice an opening you would use again, actually thinking at one or two points in the game on "What do I do next ? What are my plans ? What is my opponent intending ?". At least at two or three times in the middlegame you will slow down and calculate a few lines. Calculating is useful training. Maybe you will still have thirty seconds or one minute to invest for an important decision in the rook endgame; in bullet the endgame is never reached, or butchered until a player gets flagged.
The fast, repetitive, mechanical play, which is almost mandatory in bullet because of time pressure (also in blitz, actually, but less so) is actually rather hampering your progress, because you keep making bad moves and teach yourself to play automatically, not calculating. Also playing for tricks and cheapos (if he doesn't see this I will fork his queen...) is the wrong mindset for when you'll play real chess.

Anyway, don't expect too much progress from a 10' practice. The blitz might or might not help a tiny little bit, but you will need to invest more time and various training (play, analysis, exercices, books/videos on openings/middlegame/endgame, etc.) if you want to achieve significative progress. The bullets, if anything, are counterproductive.


What's the best way for someone to use their time with a chess coach? Let's say you have a 2 hour session. What questions would the serious player studying with a chess coach ask? Could you provide some examples?

The main advantage of a coach is the feedback.  Neither a book nor software can explain where your weaknesses are.  A coach should be able to review your games and explain where your weaknesses are and provide reference material to help your improve.
Once you know your weaknesses, you can use books and software to help yourself improve.  However, some chess concepts are too subtle to be explained to all but the most motivated.


Which is better, going for checkmate, or forcing immediate resignation? Let's say you have a position where you can win the opponent's queen in one move and you know he will resign; or you play a combination that is technically stronger since it forces mate, but it takes 8 moves, some of which are hard to see, so you do not think your opponent will resign on the spot.

Which is really better?

you play a combination that is technically stronger since it forces mate, but it takes 8 moves, some of which are hard to see

If they're hard to see, chances are that you've missed something as well. Therefore, take the queen. You might miss the opportunity to finish the game in a beautiful way, but you can always save that for the post-mortem analysis.

The only reason not to take it would be if you're low on time and are not sure you can finish off the game, even being a queen ahead. But I wonder how you would see the mate in 8 then :)


Shortest sequence of moves to create biggest material imbalance What is the shortest game with the largest material imbalance? This of course means that one side will have 9 queens, 2 rooks, 2 bishops, 2 knights, and a king, and a bare king on the other side. From some experimenting, I got this:

[FEN ""]

1.h4 g5 2.hxg5 h6 3.gxh6 Rh7 4.g4 Rg7 5.h7 Rg6 6.h8=Q Bh6 7.g5 f5 8.f4 e6 9.e4 d5 10.d4 c5 11.c4 b5 12.b4 a5 13.a4 Qe7 14.exf5 Bb7 15.fxe6 Bc6 16.cxd5 Bb7 17.bxc5 Bc8 18.axb5 Bb7 19.c6 Bc8 20.Rxa5 Ra7 21.b6 Rd7 22.Qe5 Nf6 23.b7 Kf8 24.c7 Rd6 25.f5 Kg8 26.Nc3 Bd7 27.c8=Q+ Kh7 28.Qc4 Nc6 29.b8=Q Be8 30.Bd2 Qf8 31.e7 Qg7 32.Bg2 Bf7 33.e8=Q Re6 34.dxe6 Bg8 35.d5 Nb4 36.d6 Nc6 37.d7 Nb4 38.d8=Q Nc6 39.e7 Nb4 40.Qdd7 Na6 41.Qed8 Nc5 42.e8=Q Nd3+ 43.Qcxd3 Ng4 44.f6 Ne3 45.f7 Nf5 46.f8=Q Qf7 47.Qfb4 Rg7 48.g6+ Kh8 49.gxf7 Ne7 50.Q3d6 Kh7 51.Q6xe7 Kh8 52.f8=Q Kh7 53.Qed5 Rf7 54.Bh3 Kh8 55.Q7xf7 Bg7 56.Ke2 Kh7 57.Ke3 Kh6 58.Kf4 Kh7 59.Q8xg8+ Kh6 60.Qgxg7#  0-1

This can of course be improved though, as I was essentially moving pieces around randomly.

I got this, which is much shorter.
[FEN ""]

1. a4 a5 2. b4 b5 3. c4 c5 4. d4 d5 5. e4 e5 6. f4 f5 7. g4 g5 8. h4 h5 9. bxa5 Bd6 10. axb5 Be6 11. dxc5 Nf6 12. cxd5 O-O 13. fxe5 Rf7 14. exf5 Ra6 15. gxh5 Rb7 16. hxg5 Rbb6 17. bxa6 Nc6 18. axb6 Qe7 19. dxc6 Kh8 20. cxd6 Ng8 21. a7 Qf6 22. gxf6 Ne7 23. b7 Bd7 24. e6 Ng8 25. c7 Kh7 26. f7 Kg7 27. e7 Kf6 28. h6 Ke5 29. f6 Kf5 30. a8=Q Kg6 31. b8=Q Ba4 32. c8=Q Bb5 33. f8=Q Bc4 34. d7 Bd5 35. d8=Q Be4 36. f7 Bf5 37. e8=Q Bd7 38. h7 Bc6 39. h8=Q Bb7 40. Qcxb7 Kf5 41. fxg8=Q#

It's one move above the lower bound, but I feel that this is optimal.

As @Evargalo suggested, here is @user1583209's proof of optimality from their comments.
"I have a proof now: Start by labeling the columns/files by numbers, i.e. a=1, b=2...h=8. Then for each pawn calculate the sum of the respective files. So in the initial position this sum is 1+2+3...+8=36. Now, if a pawn captures, it changes its file by "1" (either plus or minus 1). In order to achieve a solution in 40 moves, we have to queen the pawns on each of the squares on the 8th rank. This means that in the final position the sum of files (for pawns+promoted pawns now) needs to be 36 again. However we also need to do 15 captures with these pawns.
Each capture changing the file sum by 1, it is impossible to end up with 36 as sum, basically because 15 is an odd number.  (If you have x captures to the left and y captures to the right you end up with equations: x-y=0 and x+y=15 which has no integer solution) That proves that it is impossible to achieve a solution in 40 moves and the solution with 41 moves given by orlp is optimal."


Which opening requires the longest amount of chess moves? For most openings that I play (e4 and d4 openings) I have observed that they take exactly 4 moves (e.g. Giuoco Piano Game without variation).

C50: Giuoco Pianissimo, Italian four knights variation takes 5 moves.
The Van't Kruijs Opening (1. e3) takes less than 1.

Which opening requires the longest amount of chess moves?

Edit

As I see I have been unclear, let me clarify. When I say two distinct openings, all I mean is a different name. For example, Ruy Loypez, XXX Variation is different from Ruy Lopez Ppening is different from Ruy Lopez, YYY Variation.

Here is one possible answer: there is an eco.json file available which is based on the Encyclopedia of Chess Openings. If you take the contents of that file and sort the openings by the length of the line leading to the named position, there is a unique winner, the 36 plies long Ruy Lopez: Marshall, Main Line, Spassky Variation:

{'c': 'C89',
 'f': '5rk1/5ppp/p1pbr3/1p1n3q/P2P2b1/1BPQB1P1/1P1N1P1P/R3R1K1 w -',
 'id': 3320,
 'm': 'e2e4 e7e5 g1f3 b8c6 f1b5 a7a6 b5a4 g8f6 e1g1 f8e7 f1e1 b7b5 a4b3 e8g8 c2c3 d7d5 e4d5 f6d5 f3e5 c6e5 e1e5 c7c6 d2d4 e7d6 e5e1 d8h4 g2g3 h4h3 c1e3 c8g4 d1d3 a8e8 b1d2 e8e6 a2a4 h3h5',
 'n': 'Ruy Lopez: Marshall, Main Line, Spassky Variation'}


does anyone use OSX Xboard app in Mavericks? There's been talk about this app's release but I don't seem to be able to track it down and download it.  I'd love to have Xboard native app for my Mac.  Can anyone help?  Any help appreciated greatly.

Winboard is what can run in wine. Though macwine is limited to 32bit executables.   Xboard on the other hand always could be compiled in OSX just fine!  I created an .app package ready for use and I'm told works fine in 10.10-10.6

It is a GTK2 app running through Quartz, so no X11 server app is needed.

http://www.open-aurec.com:8080/wbforum/viewtopic.php?f=19&t=53274&p=200662#p200662


The number of levels in chess Consider a weak chess player who has just learned how the pieces move and who will lose to a Scholar's Mate. (We can say that he's male and call him "Mr. Newcomer".) Let's define Mr. Newcomer's level to be 0. Moreover, let's say that player A is a level above player B if A's expected score against B is 0.9 (for example, 9 wins and 1 losses in 10 games). Given these definitions, at which level would you find a player like Magnus Carlsen (who is currently the player with the rightest rating in the world)?

I have a feeling that you can give a quite exact answer to this question if you know Carlsen's rating (which is 2872 at the time of writng) and Mr. Newcomer's rating, and if understand the rating system better than I do...

The choice of 0.9 in the above definition of a "level" is pretty arbitrary; if you think a number like 0.8 or 0.7 makes more sense, just pick that number instead.

The rating system already kind of allows you to calculate this since you can convert any rating difference into an expected score using the formula: expected = 1/(1 + 10^(diff/400)) so a rating difference of 382 points should give you the .9 expected score.

Therefore Magnus Carlsen at 2872 should score 90%  (which could be 9 wins and one loss out of 10 games or 8 wins and 2 draws) against a player rated 2490.  and that 2490 player should score the same against a player rated 2108 and so on.

So you could keep subtracting 382 from Carlsen's rating until you got to a rating of about 100 which is probably what the worst chess player could be.  if you subtract 7 times you get down to 198, so I guess you could say Carlsen is 7 of your levels above the weakes beginner.

Now a rating difference of 200 translates to about a .75 expected score  and that happens to be the rating difference that the USCF uses for different classes.  For example: Master = 2200 - 2399 /
Expert = 2000 - 2199 /
Class A =  1800 -1999 /
Class B - 1600 - 1799 /
Class c - 1400 - 1599 etc..

so you can kind of think of each class as a "level" like you describe where the middle of each class has about a .75 expected score against the middle of the next lower class. So you could say that using that criteria, Carlsen is about 14 "levels" or class above the weakest player.


Can I play chaturanga on any of the main chess sites? Inspired by this question What rules are known for Chaturanga?
Chaturanga seems quite interesting, and some aspects of it, like no castling are being introduced in other variants: Kramnik's chess. Given that, say, lichess.org has so many variants, is there a reason why Chaturanga is not of them?
Possible reasons:

The rules are not exactly known.

Queen (Mantri) is much less powerful and pawns don't have a 2-square move option on the first move, which makes the game less interesting / drawish to many people.

Strategies were developed to draw fairly easily, (and that's why rule changes were introduced). This is a stronger version of 2), and probably not likely.

You answered your own question, with 1) and 2) being the main causes!
I don't know about 3), tbh, but it seems at least somewhat plausible (although stalemate was also a win in chaturanga so who knows!).
You say that it's not on main chess sites, but chess.com at least has it as a playable variant- can't speak for how easily you'll find a game there however.
It's also presumably not trivial to code the game, which is probably another reason why.


Can Black reach full equality? [FEN "r3kb1r/ppqn1ppp/2p1pn2/4Nb2/2BP4/2N5/PPPBQPPP/2KR3R b kq - 0 10"]

This position is taken from super GM game, so I am fully aware that Black might be busted here and that this question might remain unanswered. Please try to post only relevant comments and answers, i.e. ones that demonstrate a path to equality for Black.

First, black is hardly busted here, and Stockfish 11 confirms this with both 10...Be7 and 10...b5 being 0.00 at a depth of 30. 10...Bb4 is also reasonable. That said, as I force in the moves it believes are best, it eventually sometimes thinks white has a slight pull, which is not surprising given the clear space advantage. At the same time, in practice, per the Mega 2020 database, the white wins 72.3% of the time from this position, so unless you play like a computer, you still may lose, and there are a virtually infinite set of possibilities for white to play while black is walking a fine line all the way. This is a line I would try to avoid in practice, and keep out of my repertoire as a matter of course.

I do not play the Scandinavian, but I have played the Caro-Kann for a long time, and this is very similar to one of the main lines, and what I can say about both is that white has more space, and that is not going away for a while, and thus this is always a little uncomfortable for black...a typical plus-equals position. In both, black must finish development, especially securing the king here since it is vulnerable to tactics, and then eventually break back with c5. Other times, it ends up an opposite-side attack.

Most players here have played 10...Nxe5, which is horrible from both a Stockfish perspective at +1.3, and a winning percentage perspective at 82.2% for white. It is not a good move in a practical game as it solidifies white's space advantage with tempo, and puts the Bf5 at risk immediately to 10...Nxe5 11. dxe5 Nd5 12. g4 Bg6 13. f4 with a solid advantage.

You cannot get a 100% answer to your question as it is too early in the opening to say as it is with virtually every reasonable opening where white has a small space advantage. It will always feel like white has a small advantage until it eventually levels out...or doesn't. That is chess.

This is very close to equal, and super GMs would hold it, so the way I would play it is the solid 10...Be7. After that, there are basically two plans for white. To move the Bc4 to b3, playing prophylactically, or to play Rhe1, and eventually expand on the kingside.

There are an incredible amount of possibilities here, but this will give you a place to start.

P.S. In a position like this, and this one is not unique, there are so many reasonable lines that it is unclear which is best for the stronger side, and thus, there are literally millions of possibilities from the moment you play 10...Be7 in just the next few moves. In cases like this, now that you have a place to start, you will need to spend a lot of time on your own with a computer not just to get a few more specific lines, but also to get a feel for the plans and move orders that may occur. Since you cannot possibly memorize every possibility, you are almost certainly going to end up on your own sooner than later, and what you need to develop is a sense of HOW to play the position correctly.

 [FEN ""]

  1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 Nf6 5. Nf3 c6 6. Bc4 Bf5 7. Bd2 Nbd7 8. Qe2 Qc7 9. O-O-O e6 10. Ne5 Be7 11. Bb3 {Prophylactically avoiding b5.} (11. Rhe1 O-O 12. Bf4 Bd6 13. Kb1 Nd5 {And this is equal but for the one move I cannot imagine anyone playing.} 14. Bxd5 exd5 15. Nxd7 Bxd7 16. Bxd6 Qxd6 17. Qe7 Qc7 $14 {But it is the smallest of edges as rooks will soon be traded.}) 11... h5 $1 {Securing the Bf5 from g4.} 12. Bf4 Bd6 13. Rhe1 a5 {Equal per the computer, and with good counterplay.}

Here are some lines based on your supplemental questions in the comments.

 [FEN ""]

 1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 Nf6 5. Nf3 c6 6. Bc4 Bf5 7. Bd2 Nbd7 8. Qe2 Qc7 9. O-O-O e6 10. Ne5 Be7 11. f3 (11. f4 $6 {This is just too slow, and leads to black being better.} b5 12. Bd3 (12. Bb3 h5 13. Rde1 {And if the computer thinks that this is best, something has definitely gone wrong for white.} Nb6 $17) (12. g4 Nxe5 13. fxe5 Nxg4 14. Bd3 (14. Bb3 a5 $17) 14...Bxd3 15. cxd3 h5 $15) 12... Bxd3 13. Nxd3 b4 $15) (11. h4 {Again, too slow.} b5 12. Bd3 Bxd3 13. Nxd3 a5=) (11. h3 b5 12. Bb3 (12. g4 Bxc2 13. Bxe6 Bxd1 14. Bxf7+ Kf8 15. Rxd1 Nxe5 16. dxe5 Kxf7 17. exf6 Bxf6= {Up an exchange, but white has activity. It is dynamically equal.} 18. Qf3 (18. g5 Be5 19. Qf3+ Kg8 20. Qe4 {Transposes.}) 18... Kg8 19. g5 Be5 20. Qe4 Rd8 21. Kc2 Qe7 22. f4 Bd6) 12... a5 13. g4 Bg6 14. g5 (14. Nxg6 hxg6 15. a4 b4 16. Ne4 Nxe4 17. Qxe4 Nf6 $14 {White has maybe the tiniest of edges here. The Bb3 is not really well-placed.}) 14... Nd5 15. Bxd5 $1 (15. Nxd5 exd5 16. Nxg6 hxg6 17. Rde1 Nb6 18. a3 a4 19. Ba2 Kd8 20. h4 Bd6=) 15... exd5 16. Bf4 Qb7 17. Rhe1 (17. Nd3 Bxd3 18. Rxd3 Nf8 19. Be5 Ng6 20. Bxg7 Nf4 21. Qd2 Nxd3+ 22. Qxd3 Rg8 23. Qxh7 Bxg5+ 24. f4 $3 {To lure the B to a square that Qf5+ is a threat later.} (24. Kb1 $2 O-O-O 25. Qf5+ Qd7 26. Qxg5 f6 27. Qxf6 Rxg7 $17) 24... Bxf4+ 25. Kb1 O-O-O 26. Bf6 Bd6 27. Bxd8 Rxd8 28. Rf1 Rf8 $14 {But almost equal.}) 17... O-O $1 18. Nxg6 fxg6 19. Qxe7 Rxf4 $14 {But black has good counterplay against the weak pawns.}) 11... h5 12. Bf4 (12. Bd3 {The computer likes this move, but I cannot imagine that it gives white a lot.} Bxd3 13. Nxd3 b5=) 12... b5 13. Bb3 (13. Ng6 Bd6 14. Bxd6 Qxd6 15. Nxh8 bxc4 {And Ke7 next.}) 13... Bd6 14. Kb1 a5 {With complicated play for both sides that the computer says it equal.}


Most effective way to achieve a 2000+ rating in one year, starting as a 1600? I currently play at around a 1600 level, and have stagnated in terms of rating improvements for quite some time.

I have always played chess recreationally, occasionally doing tactics puzzles here and there, but I've never done any professional studying.

I was wondering what the most effective way of improving my rating to 2000+ would be.  If there are links to scientific research on the topic, I would appreciate it.  Book recommendations would also be great.   I'm mostly looking for a discussion about what exercises maximize your return on rating-- opening, tactics, positional understanding, end games, analyzing grand-master games, analyzing your own games, etc.

Gaining 400 points in a single year is not a reasonable goal for an adult playing at 1600. To do this, you will need to be +25 against your peers, where a peer is someone with the rating you have at the time the game is played.

That being said, if you're going to try it, the first step is to get an instructor. Your instructor will be able to identify the weakest parts of your game and help you shore those up.  Since you want to end up at 2000, I'd recommend an instructor rated no less than 2200.

The maximum return will likely be on tactics.  You'll need to be decent at two openings as white and two as black.  Know the philosophy behind the openings - don't just memorize the moves.


Does ECO openings classification have an established more detailed specification - by sub indexes? For example an ECO index B33 can be used to describe opening theory that barely fits into a thick book. Is there an established system to classify variations further? I have seen examples of indexes that look like B33/01, or B33/22 but I wonder if those are well documented anywhere?

A particular ECO index might split further into sub-indices like B33a, B33b, B33c, etc. The number of such sub-indices varies (maybe it goes up to y, or only to t, or ...), and some indices don't have any sub-indices. As for a place where these are well-documented, the free database program Scid does a great job. It automatically tells you what ECO classification you are in as you view/enter a game. More than that, though, you can bring up its ECO Browser that offers a summary of the ECO code you're in if you want to see the sub-indices laid out.

For instance, when I opened Scid and entered the moves 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6, the info panel below the board indicated that we had entered into ECO index B33a. That text is clickable, and doing so brought up Scid's summary for ECO B33, complete with variation names and clickable lines (which will bring the final position up on the board), as seen in the following image:


How does Black escape perpetual check here? In this position, what is a clear line in which Black escapes from perpetual check?

[FEN "2k5/7p/p1Q3p1/3pP3/1r2qP2/1P4PK/P7/8 b - - 0 1"]

It seems that the black king can escape via a5/

[FEN "2k5/7p/p1Q3p1/3pP3/1r2qP2/1P4PK/P7/8 b - - 0 1"]

1...Kb8 2.Qd6+ Kb7 3.Qd7+ Kb6 4.Qd8+ Kb5 5.Qb8+ Ka5 {Kc5? 6. Qd6 Kd4?? 7.Qxb4} 6.Qc7+ Rb6 7.Qc5+ Rb5 8.Qc7+ Kb4 {and you go for the hills.}

edit: 5.a4+!, noticed by @jknappen, is problematic. The right solution is rather to bring the king to a7 before covering checks with ...Rb7, as in @InertialIgnorance 's answer which should become the accepted one.


What exactly happened in the Open World Blitz Championship in game Carlsen-Alireza? In the 19th round of the World Chess Blitz Championship in Moscow, Russia, Magnus Carlsen faced Alireza Firouzja with black. Alireza lost on time while he was trying to restore a piece he dropped.

It's said that he made multiple appeals to the CA IA Takis Nikolopoulos. What exactly happened and what was the final outcome of the game?

As you said, Alireza Firouzja lost on time while he was trying to restore a piece he dropped. He appealed, but the appeal was denied.

It was denied for several reasons.

First, he appealed about Magnus uttering one frustrating word earlier in the game. That was denied because had he wanted to appeal that, he had to do it right then and there, but he did not.

He questioned whether the clock was in proper operating order, but that was also denied.

He was declared lost because, no matter how unlikely, there was a position that Magnus could mate him in.

  Paragraph 6.9 of the FIDE Laws of Chess state:

  The game is drawn, if the position is such that the opponent cannot
  checkmate the player’s king by any possible series of legal moves.

It is my understanding that the formal appeal was on the Magnus' utterance as Alireza Firouzja had already been shown the rule in the rule book, so I do not believe that he formally appealed that part of the ruling.


What is the correct pawn promotion procedure? This may be a frivolous question, as I believe that most chess players are good sportsmen, but I was wondering: what is the technically correct procedure for promoting a pawn to a queen? Do you ask your opponent to put the queen on the promotion square, or do you take it from his pile of captured pieces yourself (provided of course that queens have been exchanged)? If you have to ask your opponent, what happens if he takes his time (as in the case where you may be in time trouble, for example?). If you have to take it yourself, are there rules around where you are allowed to keep captured pieces (the absurd situation being that your opponent hides the captured queen when the promotion becomes evident).

Similarly, I vaguely remember that there was some professional game that got delayed because they couldn't find a second queen after one of the players promoted while still having his original queen on the board. This puzzled me a bit: in my school days, we would either use an upside-down rook or even a pawn rested on its side to mark it as a queen - is this for some reason unacceptable in tournament play?

The procedure is (FIDE rules): move the pawn to its promotion square, then replace it with the piece you want. You can take it from the captured pieces yourself, your opponent does nothing. If the piece isn't readily available, you can stop the clock and ask the arbiter to bring one. Your choice of piece is only finalized when it touches the promotion square. See the Laws of Chess

An upside down rook is a rook. A pawn on its side is a pawn, and thus an illegal move.

The FIDE rules will be changed a bit in the upcoming July 2014 Laws of Chess, see e.g. this ChessCafe "Arbiter's Notebook" column by Geurt Gijssen, who is involved in the rules changes. From July, it will also be legal to remove the pawn from the board without moving it to the promotion square (followed by putting the piece on the promotion square), and it will also be legal to place the piece first and then remove the pawn. Those used to be illegal moves.

And also from July, if you move the pawn to the promotion square and then press the clock, you've made an illegal move (that's already the case now), and as usual the pawn counts as touched and you will have to promote it in the legal way, but you will be forced to promote to queen. Apparently people were using this illegal move and the delay it will bring as extra thinking time to decide which piece to promote to.

As you can see there are some fiddly details that may be different with USCF rules, but I don't know those.


Why is bishop slightly better than a knight? While i was going through the chess piece values, Bishops is worth 3.30 points while Knight has 3.0 points.

  Although the 1/3/3/5/9 system of point totals is the most commonly
  given, many other systems of valuing pieces have been proposed.
  Several systems give the bishop slightly more value than the knight. A
  bishop is usually slightly more powerful than a knight, but not always
  – it depends on the position (Evans 1958:77,80), (Mayer 1997:7). A
  chess-playing program was given the value of 3 for the knight and 3.4
  for the bishop (Mayer 1997:5)
  https://en.wikipedia.org/wiki/Chess_piece_relative_value.

Please explain why is a bishop slightly better than a knight? I know it depends on the position for like as bishops, a knight can also have high points if it is placed on outpost.

Here are the reasons:

Bishops are stronger than knights in open positions, and open positions are more likely than closed ones. If you think of the endgame in particular, many pawns have been exchanged, i.e. many end games are open, favouring the Bishop
The Bishop pair is an advantage, as the light square bishop covers the squares the dark square bishop doesn't and vice-versa. So 2 bishops together compliment each other, but the 2 Knights do not. They actually replicate each other, potentially making one of the Knights rather redundant
In an endgame, a Bishop can cover both the Kingside and Queenside because it is a long distance operator, meaning it can perform offensive and defensive duties at the same time (e.g. help push a friendly passed pawn and stop an enemy passed pawn at the same time in a race). The Knight cannot do the same


Is the notion of an en passant redundant? The en passant move can be utilised when a pawn is offered the option of being able to capture an adjacent file’s pawn, which has advanced two ranks. However, surely the game of chess would be fine enough with the absence of the en passant rule? Yes, it does indeed help locked up pawn structures to not occur, but I do not entirely understand the genuine purpose of the en passant.

If nothing else, it does help to make similar looking pawn structures, behave similarly independent on which row they occur.

For instance with en-passant: white: pawn h5, black pawns on h6, g7 would be somewhat equal to the position where white: pawn on h4, black pawns on h5, g6.

Without en-passant however black would be able to achieve a protected passed pawn (often a huge advantage in many endgames) in the first situation by simply playing g7-g5 without being in danger of being captured.

Thus not having en-passant would change the evaluation of many endgames and complicate rules somewhat because now you'd have to consider on what row the pawns are as well.


Connecting UCI engine with iOS? So I'm not actually making a Chess app, but I am trying to hook up an engine that uses a protocol almost exactly the same as UCI. I can get it working quite easily on a macOS app. Now, the hard part is integrating an engine like Stockfish into an iOS app.

You can't use std input/output nor can you fork a process, so how should one manage the protocol for communicating moves to a UCI interface? I've managed to include the engine C++ library and can communicate via UCI commands in the debug console but I have no idea how to simulate std input into the engine from iOS. Should I look for hooks within the engine to call directly and simulate the game loop in Swift?

I apologize if this is the wrong community for this question, but UCI specific questions go over the head of most SO users so I thought I might try here. There are a plethora of iOS chess apps so I'm genuinely curious how people are integrating their engines into their apps.

Simple. Inter-thread communication. Specific implementations could be:

Internal UCI queues
Find the UCI loop function then hook it up (e.g. UCI::loop in Stockfish).
Redirect the standard input/output into pipes

Few points:

It's not a good idea to do your works with Swift, because Swift has poor support for C++. I prefer Objective-C as it works with C++ at the source level.
Redirecting is recommended if you're confident. All my iOS apps use that. You just need to send your UCI commands to a redirected pipe, while the engine receives them from the standard inputs (redirected). This is not a place for discussing unix programming, please ask Stackoverflow. It works.


What kind of statistics should I run on a database? I have written a python script to verify the strategical rule of "controlling the center".

I have parsed the free 2.2 million games database (it takes about 5 minutes) and I have found that the winner of a game controls the center at any given time with (on average) 1 more piece than the losing side.

I'd like to look at the correlation of other strategical principles with winning. What would you suggest would be an interesting list to look into?
(I'm thinking of castling vs no castling, knights on the rim...)

EDIT: I would like suggestions for interesting statistics that you would like me to run. I could then send an article (say, to chess.com, or TWIC) with the results, referencing the suggestions posted here.

To extend your center squares analysis, it might be interesting to determine the expected winning percentage in the database when one side has 0, 1, and 2 pieces on average central square advantage.  This would begin to show just how important the advantage is as I would think the winning percentage would increase as the advantage becomes more pronounced.

Also, a knight on c3 covers two central squares e4 and d5.  Are you counting the number of times the central squares are controlled or are you counting just the knight on c3 once?


What is a good size chess board for an eight-year-old? I'd like to buy my nephew a folding wooden chess set for his birthday.

When I played with my own children when they were smaller it was hard for them to go more than a few minutes without fidgeting and jiggling that inevitably upset the board, so I am pretty sure that the larger the pieces are, the better the experience will be for everyone.

Is something like this or this 10" set likely to be too small? Or is it better to have something larger?

I want a folding set that he can safely put away with the pieces in it. I don't really see the point of a magnetic board, I'd rather just have heavier pieces. I'd be glad to hear out any experiences and advice.

Larger pieces and board may help to keep a better overview for a beginner. As soon as his interest in chess becomes more serious, he will start to be careful with the board, so I wouldn't pay too much attention to the weight of the figures, most sets aren't heavy enough to withstand mechanical force (unless you choose marble pieces).

I'd recommend around the 14" or larger, keeping in mind though that as long he's not actively playing the set could just be one more toy cluttering the shelves in his room.


Alphazero Learning vs Playing mode Is there any fundamental difference (in algorithms etc.) between Alphazero training by playing against itself and when playing a match against Stockfish?
Or were the match games basically treated as training game with the only diferrnce that half of the moves were coming from outside?

Also, did they use the same hardware during training and match?

AlphaZero trained itself by self-playing. It used the gradient descent algorithm for convergence (equation 1 in the paper). Please note the training phase had nothing to do with Stockfish.

Later, Google matched the "fully trained" AlphaZero against Stockfish. It's like you practice chess with yourself for four months, participated in a tournament then won all your games!

Hardwares were different in training and playing:

  Training proceeded for 700,000 steps (mini-batches of size 4,096) starting from randomly initialised parameters, using 5,000 first-generation TPUs (15) to generate self-play games and 64 second-generation
  TPUs to train the neural networks.

and

  ... in chess, shogi and Go respectively, playing
  100 game matches at tournament time controls of one minute per move. AlphaZero and the previous AlphaGo Zero used a single machine with 4 TPUs...


Refutation of the Blackmar-Diemer gambit? Is there an accepted refutation of the Blackmar-Diemer Gambit, 1. d4 d5 2. e4 or what is the strongest line for Black to prove that the gambit is unsound?

The simplest refutation is 2...e6, the french defense, one of the most stable openings for black.
It is also fine to accept  the gambit  2... dxe4, but you have to know some specific traps....


Why do chess tournaments allow absolutely scandalous draws? I am currently watching the Rapid World Championship and the amount of draws between players is absolutely shocking. I'm not talking about games where each player fights to the end and the game just happens to be a draw - that is perfectly okay in my opinion.

But so many games are being drawn on default - players are simply agreeing to draw far before any sort of endgame is reached. Just now, 5 minutes ago, Anish Giri drew a game after 10 moves. 10!!!  TEEEEN!!!

Why do chess tournaments allow this scandalous behavior?

Imagine if any other sport was played this way. Imagine if Barcelona and Real Madrid are playing football, and they just decide to leave the pitch after 20 minutes because they no longer want to play, and agree to a draw.

Why is this behavior not banned? Why isn't a rule enforced so that a draw can only be reached after many moves (as was the case in the World Championship with Caruana and Carlsen)?

Anish Giri was likely playing a "solved" opening, one in which all lines have been analyzed to a draw. Also, Giri is extremely hard to beat and draws many of his games (his weakness is that he doesn't often win). In this situation, there was likely no room for progress outside of severe blunders, so it's almost a respect issue, where Giri and his opponent respected each other enough to admit that no blunders were likely to be made, especially in this line. This sort of "guaranteed ending" does not occur in games like football or baseball or whatever.


Exercises on dynamic play I feel I learn best from solving exercises and I'm looking for a resource that focuses on "dynamic play" such as going for dynamic advantages at the expense of static/material aspects and how to treat the resulting positions. Any recommendation for an exercise book or an online resource?

I can recommend The Attacking Manual.

From the Quality Chess homepage: "British Champion Jacob Aagaard explains the rules of attack (the exploitation of a dynamic advantage) in an accessible and entertaining style. This groundbreaking work is well balanced between easily understandable examples, exercises and deep analysis."

To benefit from this book you should be an advanced player, maybe 1900 Elo or above.

The Attacking Manual contains explicit exercises. An alternative is to just play through dynamic games from a book and try to guess the next move. For example you could search the game on chessgames.com or on chessbase, make sure you can't see the moves and then go through it until you find an interesting position. Then you calculate and write down all your variations. Afterwards you go back to the book and find out how accurate your reasoning was.

Books with great dynamic chess are Life and Games of Mikhael Tal, Storming the barricades or Fire on Board.


How to search for a particular opening on the Internet I am very new to forum and formal chess play.  Please bear with me.

I would like to be able to search for an opening that is being used.  How would I search for that on Google or another search engine?  I do not know many opening names, only a few.  Would I use E3 white...etc.?  Any guidance on this will be appreciated.

My advice to you would be to start off by learning 2 openings in chess. Italian Game (white)and French Defense(black), those will help you learn chess in many types of positions, both closed and open games.

http://chesstempo.com/game-database.html

This will provide you with many more openings, and their statistics. Although don't focus too much on the statistics, as those won't win you a game.


Specific for Lasker during 1904 Cambridge Springs tournament I have heard that Emanuel Lasker, during the great historical tournament in 1904 (in Cambridge Springs), had to face some specific which was imposed on him. I am wondering what could be meant by that? Was there any kind of handicap with which he had to deal with?

Most of the sources I could find on the internet do not mention any kind of special specific for Lasker.

From 1902 to 1907 Emanuel Lasker was living in the USA and concentrating more on algebra than on chess. His paper Zur Theorie der Moduln und Ideale was published in March 1905 in Mathematische Annalen and will lead to the famous Noether-Lasker theorem.

It seems he also worked on some papers in the field of philosophy, but I know less about it.

Chess was not his main preoccupation during those years, and his participation in Cambridge Springs tournament in 1904 was a short chess parenthesis in his mathematical works.

There is no indication that Lasker was playing with any handicap in that tournament, beside lack of practice and training, and this seems very unplausible to me.

A few years later, Lasker will go back to "wasting his wonderful mind" on chess, according to a famous Einstein's quote that may be less apocryphical than most Einstein's quotes.


What's the rationale behind chess engines conditionally allowing threefold repetitions when assigning a draw score? When a chess engine sees a position p repeated once (i.e. position p occurred twice) it immediately assigns the second occurrence of position p a draw score. This makes sense because position p doesn't need to occur thrice in order for the chess engine to realize that it's not making progress (i.e. a twofold repetition is just as drawn as a threefold repetition).

Many chess engines do just this. They assign a draw score to all twofold repetitions. However, some of the best chess engines such as Stockfish and Ethereal don't assign a draw score to all twofold repetitions. If the first occurrence of position p is not strictly after the root node then they don't assign a draw score to the twofold repetition. Instead, the position needs to be repeated twice (i.e. it needs to be a threefold repetition) in order for it to be assigned a draw score.

For example, consider the following drawnByRepetition function from the Ethereal source code:

int drawnByRepetition(Board *board, int height) {

    int reps = 0;

    // Look through hash histories for our moves
    for (int i = board->numMoves - 2; i >= 0; i -= 2) {

        // No draw can occur before a zeroing move
        if (i < board->numMoves - board->fiftyMoveRule)
            break;

        // Check for matching hash with a two fold after the root,
        // or a three fold which occurs in part before the root move
        if (    board->history[i] == board->hash
            && (i > board->numMoves - height || ++reps == 2))
            return 1;
    }

    return 0;
}

As you can see either i must be greater than the root node (i.e. it must come after the root node) or the position p needs to be repeated twice (i.e. it must be a threefold repetition) for it to be assigned a draw score.

The chess programming wiki has the following to say about assigning draw score to repetitions:

  Threefold repetition implies a position occurred thrice, that is repeated twice. When to score the position as a draw, however, is an entirely different matter. Most programs do this on the first repetition, no matter whether the first occurrence of the repeated position appears in the current search space, or not. Other programs consider that fact, they avoid cycles inside the current search tree to make it a directed acyclic graph (DAG), but allow a one-fold repetition, if the first occurrence appears in the game history before the current root. Anyway, to wait for the second repetition one has its pros and cons. The Repetition score is either zero or the contempt factor.

It says that “to wait for the second repetition one has its pros and cons.” So, what exactly are the pros and cons? I couldn't find an explanation as to why top chess engines like Stockfish and Ethereal do this.

It says that “to wait for the second repetition one has its pros and cons.” So, what exactly are the pros and cons? I couldn't find an explanation as to why top chess engines like Stockfish and Ethereal do this.

My discussion will be technical, so let's make it as simple as possible. Firstly, let's make be clear about this:

  If the first occurrence of position p is not strictly after the root node then they don't assign a draw score to the twofold repetition.

Why would an engine do that? Let's consider two scenarios where we have three-fold repetition during the search. Let's assume we are on move 30th, and the engine is thinking at move 40th.

The position repeated and played on the board, for example, the position occurred on move 24th and 26th.
The position never actually played on the board, but it is part of the search. The position occurred at move 35th. (IMPORTANT - only a single repetition)

Scenario 1

In the first scenario, it's a repetition that we all understand. In your code example:

++reps == 2

So, if a position repeated twice earlier in the game before the root (root == current board position), it's a three-fold repetition. Very simple.

Scenario 2

What about the second scenario? You have the identical position on move 35th, and the same position come back on move 40th. Thus, it's reasonable to assume if you search further you will encounter the position again (for the third repetition). For example, move 45th.

Your code example:

i > board->numMoves - height

  So, what exactly are the pros and cons?

Pros: search quicker and deeper

Cons: you assume the same position would occur again later in the search (e.g. move 45th), which is not always true

  I couldn't find an explanation as to why top chess engines like Stockfish and Ethereal do this.

Search quicker and deeper. Common optimization in modern chess programming.


Why wouldn't black take the rook here? This puzzle starts on move 19 of the below game. In order to get the puzzle correctly, it seems that you have to believe that black would not take the rook with 20.. gxf6. But I don't understand why this is – it's true that black will expose their king and breakup their pawn structure, but this seems like a small price to pay for taking the rook.

I ran it through the chess engine and it didn't seem to show any obvious traps that black would run into by taking the rook.

[FEN ""]
1. d4 d5 2. e4 dxe4 3. f3 { D00 Blackmar-Diemer Gambit: Gedult Gambit } Nc6 4. c3 Nf6 5. a3 e5 6. Be3 exd4 7. cxd4 exf3 8. Nxf3 Bg4 9. Bb5 a6 10. Bxc6+ bxc6 11. O-O Bd6 12. Qc2 Bxf3 13. Rxf3 Qd7 14. Nc3 O-O 15. Bg5 Be7 16. Raf1 Qxd4+ 17. Kh1 h6 18. Rf4 Qb6 19. Bxf6 Bxf6 20. Rxf6

After 20 ... gxf6 21 Ne4 black is in serious trouble. The threat is 22 Nxf6+ followed by 23 Qh7 mate, and in avoiding this she will have to make serious concessions. An example and not unreasonable line:

[Event ""]
[Site ""]
[Date "????.??.??"]
[Round ""]
[White ""]
[Black ""]
[Result "*"]
[FEN "r4rk1/2p2pp1/pqp2R1p/8/8/P1N5/1PQ3PP/5R1K b - - 0 1"]

1...gxf6 2.Ne4 Rfd8 3.Nxf6+ Kf8 4.Qh7 Ke7 5.Re1+ Kxf6 6.Qxh6+ Kf5 7.g4+
Kxg4 8.Qg7+ Kh4 9.Re4+ Kh5 10.Re5+ Kh4 11.Qg3# *

As a  just below 1900 player I can't claim to be able to see all the variations, but over the board Ne4 is obvious enough to give me enough worries not to take the rook.To see all the glorious details stick it in an engine.


How to get position evaluation with UCI? I am trying to get score about current position directly with UCI (I am using latest stockfish). After reading the protocol I see that these commands ask engine to analyse the position:

uci
ucinewgame
position fen r1k4r/p2nb1p1/2b4p/1p1n1p2/2PP4/3Q1NB1/1P3PPP/R5K1 b - c3 0 19
go infinite

I see some information from engine, like:

info depth 30 seldepth 55 score cp -482 nodes 380021712 nps 2059916 time 184484

Then I stop it with stop and get bestmove b5c4 ponder d3c4

So it tells me the best move, but what is the score of this position.

Based on my understanding cp - 482 means that black is better almost by 5. But how can I get this information explicitly?

lines info depth with score have something begining with  pv, whereis the move. cp is centipawn, so evaluation is -4.82

info depth 16 seldepth 3 score cp -529 nodes 3409 nps 10299 time 331 multipv 1 pv b5c4 d3c4 d5b4 a1e1 h8e8 g3d6 d7b6 c4b4 e7d6 b4d6 e8e1 f3e1 c8b7 d6e 7 b6d7 e1d3 a8c8 e7g7 c8c7 g7h6 c6b5 d3e1 c7c8 h6e6 c8c1 e6d5 b7b6 d5d6

uci protocol
http://download.shredderchess.com/div/uci.zip


What Chess Software allows creating a chess Ebook? I would like to take an annotated pgn file, and convert it into an ebook I could conveniently read on amazon kindle (or its pc version), or android/Ios device. It might have to create diagrams where needed and make the book easy to go through without an extra chessboard. It would be good if the output format allowed to upload it to amazon store as well. Does such software/tool exist?

This may or may not be your cup of tea, but if you are a LaTeX user, then SCID's LaTeX export feature produces ready-to-compile LaTeX source that yields rather nice (IMO) PDFs quickly and painlessly. There are a few options regarding how/whether comments and variations are to be displayed, and diagrams are automatically included wherever you have inserted a diagram NAG D into the game score (which can be inserted the same way that move annotations like !? are when using SCID). Here's a cropped screen grab from the PDF output of a fake sample game:


Worst ELO ever in history I have a lot of questions about ratings, which are sort of connected, but I think I better split them. This is pair 1.

I googled a bit: By definition, ELO>100, and someone said (chess.com) he knows a dude with 200. I'd prefer "official" FIDE data to hearsay, though - does anyone have it? (Remember ELO began only at 2000 when it was introduced!)
Note that I can easily search DWZ (German ELO equivalent), but only for a current year.
Assume a chess program that knows the rules perfectly, but makes strictly random moves. I'm sure that experiment is so simple that it has been done yet in the computer chess league - so what was the ELO result? (Note that you can't compare this with a human who just learnt the rules. That moves will be very nonrandom, I'd bet on pawn moves...)

When I played magic the gathering, at a time when they used ELO-style ratings, I did play from time to time against the lowest rated player in the country. He was a nice chap, and very enthusiastic but I suspect he was on the “spectrum” as they say, and this makes me less eager to identify very low-ranking chess players - it doesn’t seem kind


Weakness in the Stonewall setup? In the following setup of Stonewall Attack:

[FEN ""]
1. c3 null 2. d4 null 3. e3 null 4. f4 null 5. Bd3

Wouldn't that make the king vulnerable to diagonal attacks from a bishop or a queen?
If yes, what variation of the opening may be used to counter this problem?
If no, how?
Thanks!

I used to play such as white before I got educated...

Well, it is not that bad and on the plus you don't need to learn much or any theory.

There are two possible responses from black which I found quite unpleasant to play this against.

If black does not play an early d5, he has the option for a King's Indian setup where you play d6 and e5. So black is directly fighting you on the dark squares. IMO the stonewall is almost unplayable in this case.
If black uses a standard setup with d5 and develops the bishop to f5 quickly, you end up with weak light squares and a bad dark squared bishop. Exchanging the light square bishop on d3 is not something you really want either. Black would typically put pawns on c5, d5, e6, the bishop to f5 and just develop normally.

Because of this you should stay flexible and consider other options depending on what black does. Two popular plans involve fianchetto of either bishop.

With the kingside fianchetto (g3, Bg2) you could go for a King's Indian Attack with early f4. Here you would want to play d3 and e4 eventually.


Is it possible to resign in stalemate? Say that two players, likely lower rated, are playing a rated tournament over-the-board game. Player A has a winning position, and then blunders a move and stalemates. Player B, misunderstanding the position, does not realize they are in stalemate, and immediately resigns as they believe they lost.
The game is currently a stalemate, but Player B has resigned—what is the result of the game? Can you resign in a stalemated position? At a deeper level, what is the technical point at which the game ends and the result is final: the material position of checkmate or stalemate; the players (or arbiter, if need be) agreement; the clocks stopping; or the placement kings in the middle of the board?
If this question depends on which chess organization the game is played under, while treatments of any chess jurisdiction would be useful, I’m particularly interested in USCF and to a lesser extent FIDE.

Can you resign in a stalemated position?

No. Stalemate ends the game. Nothing further is possible after that.
According to the FIDE Laws of Chess:

5.2.1 The game is drawn when the player to move has no legal move and his king is not in check. The game is said to end in ‘stalemate’. This immediately ends the game, provided that the move producing the stalemate position was in accordance with Article 3 and Articles 4.2 – 4.7.


Swiss pairing parameters I realize that there are various types of Swiss pairing systems. What would be a minimum set of parameters that needs to be specified in order to avoid ambiguity in pairings? I am thinking of parameters like "initial order", "fold/slide/adjacent pairing", ...

Does such deterministic system actually exist or will there always be some pairings that have to be decided by an arbiter or by flipping a coin?

Trying to clarify with an example: As far as I understand for any major tournament there should be rules (either set by FIDE or the organizers) regarding the way the pairings are done. These rules should specify all kinds of things like for instance, how do you pair players with the same number of points? Do you pair the strongest with the second strongest or you split the group in two and pair the first from the first group (i.e. the strongest) with the first from the second group (i.e. the one of medium strength).

Now if all of these rules/parameters have been set, is there still any ambiguity left? Or conversely, is it possible to satisfy all rules or would some get precedence in case they contradict each other?

For instance FIDE specifies that no player should play three games in a row with the same color. But if there are only two players (who both have played the last two rounds with the black pieces) with 7 points left who are therefore going to be paired. What is going to happen then? Is the FIDE rule of three same-color games going to be violated or are they going to be paired with other players first?

Basically what I am asking is, whether in practice the rules are stated and followed completely (meaning that all kinds of exceptions need to be stated) or whether pairing rules are only laid out roughly and if necessary the organizer is entitled to change some pairings?

What would be a minimum set of parameters that needs to be specified in order to avoid ambiguity in pairings?

The minimum would be to have just one rule.  Do your first round pairings by sorting players according to their ID number... and then, in the second round, do it again.  If you don't have any rules about repeating colors, scores, or meeting the same player twice, there's no ambiguity possible.  If you don't want to flip a coin to see who gets White, just declare that the highest-rated player gets White.

This would, of course, be ridiculous and unfair.  But it would be unambiguous and minimal!

  Now if all of these rules/parameters have been set, is there still any ambiguity left? Or conversely, is it possible to satisfy all rules or would some get precedence in case they contradict each other?

Assuming you have sane rules (not like the one I described above), there are pretty much going to be rules which have precedence over other rules.  If White wins more often than Black, there's no way you can have a color preference rule and a same-scores rule without one taking priority.  Under FIDE Dutch rules, there is a minimum set of "absolute" rules, and many more "quality" rules with specified precedence.

  For instance FIDE specifies that no player should play three games in a row with the same color. But if there are only two players (who both have played the last two rounds with the black pieces) with 7 points left who are therefore going to be paired. What is going to happen then? Is the FIDE rule of three same-color games going to be violated or are they going to be paired with other players first?

The following is considered an "absolute" rule:

  non-topscorers with the same absolute colour preference shall not meet

Assuming that 7 points is a "topscorer" (has over half the maximum possible points), then pairing the people with the same absolute color preference would not violate the absolute criteria.  And then, "minimize the Pairing Score Difference" has a higher priority than "minimize the number of topscorers or topscorers' opponents who get a colour difference higher than +2 or lower than -2" and "minimize the number of topscorers or topscorers' opponents who get the same colour three times in a row."  So the answer is usually going to be that the rule of three same-colored games will be violated, so as to comply with the higher-priority rule that the pairing score differences be minimized.  (It's possible that the various absolute rules would require another resolution, of course.  For example, if the two players with 7 points had already played each other, they wouldn't be able to play each other again.)

Under the FIDE Dutch rules, with the exception of the coin flip at the beginning to determine colors, the pairings are very deterministic.  They have rules like:

  All the possible transpositions are sorted depending on the lexicographic value of their first N1 BSN(s), where N1 is the number of BSN(s) in S1

which means the organizers can't ordinarily decide things like which possible transposition to take.  There's not any wiggle room.

The exception is if it's somehow impossible to comply with the absolute rules:

  If it is impossible to complete a round-pairing, the arbiter shall decide what to do.

The only scenarios I could think of where this might happen is an extremely low turnout, or a mass walkout.  (If you have 8 rounds and 8 players, you can't avoid playing the same opponent twice.  Or, if everyone who played White quit  before playing, after the first round everyone would ineligible for the bye because they'd already had a forfeit win, and after two rounds you'd also have non-top scorers that all had the same absolute color preference.)


Why is this king and two passed pawns vs. king and rook endgame not drawable? I aways thought that the king and passed pawn vs. king and rook endgame was always drawn. But I had two passed pawns in the below game,with Black to move, I was unable to draw the game. Why is that?

[FEN "8/1R6/8/5pp1/3K1k2/8/8/8 b - - 0 1"]

There is no absolute result for this type of endgame-it all depends on the position of the pieces. In fact, any result is possible.

Objectively, this particular position with black to move is a loss-you didn't make a mistake.I suggest you consult endgame tablebase, which announce a loss in 24 moves with best play by Black. Here is an example line.

[FEN "8/1R6/8/5pp1/3K1k2/8/8/8 b - - 0 1"]

1... g4 2. Kd3 Kf3 3. Kd2 g3 4. Ke1 Ke3 5. Rb3+ Kf4 6. Kf1 Kg4 7. Kg2 f4 8. Rb4 Kf5 9. Kf3 Ke5 10. Rxf4 Kd5 11. Kxg3 Ke5 12. Kf3 Kd5 13. Re4 Kc5 14. Re5+ Kd4 15. Rf5 Kc3 16. Rf4 Kd2 17. Rd4+ Kc2 18. Ke2 Kc3 19. Re4 Kb2 20. Kd2 Kb3 21. Rd4 Kb2 22. Rd3 Ka1 23. Rb3 Ka2 24. Kc2 Ka1 25. Ra3#

In the game, the White king is able to get and front of the Black pawns after Black tries to push them for promotion. White is then able to scoop them up as Black attempts to defend them with their king. Once Black is down to their king, it is a simple king and rook endgame for White. Win.

Some nice online resources about this endgame type:

General ideas and examples

More general ideas, examples and statistics

Real games collection


Queenless Imbalanced Middlegame(3) In the following position white is down the exchange, but up a pawn. Stockfish 10 and Komodo 13.2 evaluate it at 0.00. My Question is essentially which side has the advantage(if any) and if so how would that side push for a win. I don't necessarily trust the engine in this position as it's a very imbalanced position.

[FEN "5rk1/6p1/2p2r2/p1pp2N1/P4P2/1P1P2P1/2P1R1K1/8 b - - 0 1"]
[StartPly "3"]
[StartFlipped "0"]

1... Rb8

First, I think that your lack of faith in strong computers is misplaced. My Stockfish 11 quickly gets up to a depth of over 40 ply, and still reads 0.00. Just because a position is imbalanced, it does not mean they are wrong. It would be a truly exceptional case at that depth for them to be wrong. That said, regarding your sentence about who has the advantage, it is clear that only black can legitimately try to win this. White should have no prayer of winning this, but nevertheless, as with any position, if you try too hard, you can lose; and I give several lines below where it is possible for black to push too hard, and lose, or at least, be worse. I have pushed like that in similar positions myself, so I can relate.

The evaluation of the position is such:

White has one pawn for the exchange, but has several other pluses. For example, not only does white have the move, in essence, white sometimes might have two moves since black might eventually have deal with the threat of Re8 mate in some lines (right now, Rf8 would work if the Rb8 moves off the back rank). Related to that, the Ng5 is a monster for now, and combines nicely with the Re2, which will be seen in a number of lines below, and white owns the file. Black also has very weak pawns spread out over three pawn islands, which give white a lot of targets to counterattack. Lastly, and we see this in a few lines, if g7 drops, the connected passers on g3 and f4 gain a lot of strength, and provide ample counterplay.

In contrast, black has the exchange, and the possibility of c4 seriously weakening the white queenside. Ideally, black should want to trade a set of rooks since R vs. N endings with pawns on both sides are often among the easiest endings to win.

There are a virtually unlimited number of possibilities here since they all read 0.00, so you can go down any number of paths, but that demonstrates that the computer sees a GREAT NUMBER of defensive resources since white is very active. That is not to say that there is not the opportunity for a lot of play. Equal here does not equal a "dead draw" by any means.

I am going to give the two main plans that I can see for black: Trying to trade a set of rooks, and playing c4.

 [FEN "1r4k1/6p1/2p2r2/p1pp2N1/P4P2/1P1P2P1/2P1R1K1/8 w - - 0 1"]

 1. Kf3 Rff8 (1... c4 2. dxc4 dxc4 3. bxc4 $1 {This look very weakening, but white is active enough to maintain the balance.} Rb4 4. Re8+ Rf8 5. Re7 {Only move.} Rxc4 6. Ne6 Rf6 (6... Rf7 $2 7. Re8+ Kh7 8. Ng5+ Kg6 9. Nxf7 Kxf7 10. Rc8 Rxc2 11. Kg4=) 7. Rxg7+ Kh8 8. Re7 Kg8 (8... Rxc2) 9. Rg7+ Kh8 10. Re7= Rxc2 $2 11. g4 $16) 2. Ne6 Rfe8 3. Nxc5 Rxe2 4. Kxe2 Kf7 5. c3 Ke7 6. Kf3 Rh8 (6... d4 7. cxd4 Kd6 8. f5 Kd5 9. Ke3 Re8+ 10. Ne6 g6 11. g4 gxf5 12. gxf5 Re7 13. Kf4=) 7. Nb7 Kd7 8. d4 Rh2 9. Nc5+ Kd6 10. b4 axb4 11. cxb4 Rb2 12. a5 Rxb4 13. a6 Rb2 14. f5 Kc7 15. Ne6+ Kd6 {Only move.} (15... Kb6 $4 16. Nxg7 Kxa6 17. f6 Rb8 18. Ne6 $18) 16. Nxg7 c5 17. dxc5+ Kxc5 18. g4 Ra2 19. Ne8 Ra3+ (19... Rxa6 $4 20. f6 $18) 20. Kf4 Ra4+ 21. Kg5 (21. Kf3=) 21... Rxa6 22. f6 Ra7 23. Kg6 d4 24. f7 Rxf7 25. Kxf7 d3 26. Nf6 Kd4 27. g5 d2 28. g6 d1=Q 29. g7 Qb3+ 30. Kg6=


How to deal with unorthodox players? I am new to chess and know only a bit of opening theory and understand some general ideas like developing my pieces, threatening and controlling the center of the board, etc. but I struggle against players who follow no opening and just bring out the queen and run amok on the board.

How does one wanting to stick to principles deal with such unorthodox play? Am I just too new to understand that there are book responses to such moves or should I focus on repulsing pieces before I develop or should I just follow my plan for development?

Also, I would really appreciate any recommendations about resources for beginners.

Just do what you would do against 'normal' players. Develop your pieces, occupy the center, castle your king, but at the same, watch out for tactics (which, against a lone queen, means: don't leave pawns or pieces undefended).

You can harass the queen during development to gain extra tempi (e.g. 1. e4 e5 2. Qg4 Nf6), that never hurts, but you can also just wait until your development is complete, and only then attack the queen. There are no 'book moves' for this.


Convert between different rating systems Is there a table somewhere that shows how to convert between all the various rating systems?

US Chess seems to indicate that ratings would be converted from others to play in their tournaments.

I assume that you're interested in conversions involving USCF ratings. Here you can see the algorithm used.

As an example the conversion between FIDE and USCF is USCF = 180 + 0.94*FIDE if the FIDE rating is under 2000 and USCF = 20 + 1.02*FIDE if the FIDE rating is over 2000 elo points.


Do Stockfish and the tablebase work together or independently? I use Arena GUI together with stockfish in engine games. I want to download a 6-piece tablebase but that is just a lot of work (and perhaps unnecessary). If I download the tablebase (syzygy), does stockfish work with it or just waits for the board to have 6-pieces and then the tablebase makes its moves?

Here is what I mean in more detail

Stockfish working with the tablebase

I assume I have the following position:

(Note: currently I am not talking about the best moves, just an example)

[Event "Computer Chess Game"]
[White "Stockfish 8"]
[Black "Wais Kamal"]
[Result "1-0"]
[SetUp "1"]
[FEN "2k4b/3r4/8/8/1Q1q4/8/4R3/2KB4 w - - 0 1 "]

1. Qxd4 Rxd4 1-0

Stockfish consults the tablebase about what happens after Qxd4 Rxd4 (without continuing to evaluate the rest of the line). If this line is winning it goes for it.

Stockfish working alone

Stockfish continues to play the game until six pieces are left on the board, then the tablebase makes the moves.

Which one of these actually takes place?

play the game until six pieces

Stockfish doesn't do that, that's not what tablebase is for. Briefly, tablebase boosts engine search well before six-men position reached on the board.

Let's do an exercise, add the board 5 pieces. Now you have 10 pieces on the board, and it's not something you can find in any tablebase. However, during the engine search whenever Stockfish trades down to 6 pieces, it can instantly use the tablebase information. The tablebase information gives Stockfish whether's the position is a win/loss/drawn without ever going down to anything like 5 pieces. Therefore, the search is faster and more efficient.

EDIT:

The relevant code is https://github.com/official-stockfish/Stockfish/blob/master/src/search.cpp:

// Step 4a. Tablebase probe
if (!rootNode && TB::Cardinality)
{
    int piecesCount = pos.count<ALL_PIECES>();

    if (    piecesCount <= TB::Cardinality
        && (piecesCount <  TB::Cardinality || depth >= TB::ProbeDepth)
        &&  pos.rule50_count() == 0
        && !pos.can_castle(ANY_CASTLING))
    {

TB::Cardinality is by default 6. Stockfish checks how many pieces, if it's no more than 6 it consults the tablebase information. Otherwise, regular search.


Is there a way that white can survive for six moves in this position? In the below position, taken from the end of the game McDonnell-Bourdonnais, black must win. Is there a way that white can survive for six moves?

I only know some ways that white can survive for five moves as follows.

3b2rk/3P2pp/8/p7/8/2Q5/PP1pppPP/3R3K w - - 0 1

1. h4                         exd1=Q+
2. Kh2                        f1=Q
3. Qc4                        Qfxc4
4. g4                         Qcxg4
5. a3                         Qdxg1#

The White pawn must move to give the space for the king, since the queen and rook cannot prevent the black pawns from promoting to queens. Because of the Bishop on e4, white queen must defend h4. She can go b4, c4, d4, h3, f6 or g7. But it seems that nothing works.

No. According to my Stockfish, this is a forced mate in 5, whatever White tries to prevent it, and you're giving one of the (relatively) best lines. Black threatens a back rank mate by promoting one of his pawns, and the rook and queen cannot stop that. Moving the g-pawn doesn't really help, so 1. h3 and 1. h4 are the best tries.

3b2rk/3P2pp/8/p7/8/2Q5/PP1pppPP/3R3K w - - 0 1

1. h4 (1. Qxd2 f1=Q+ 2. Rxf1 exf1=Q#) (1. h3 exd1=Q+ 2. Kh2 Bh4 { threatens Qg1# } 3. Qc1 Qxc1 4. a3 Qg1#) exd1=Q+ 2. Kh2 f1=Q 3. Qd4 ( 3. Qc4 Qxc4 4. g4 Qcxg4 5. a3 Qdg1# ) Bc7+ 4. Qf4  Bxf4+ 5. Kh3 Qh1#