Chess development strategy for U16 players with the aim of producing future masters on a national scale

I'm not sure there's one best way. The best way depends on the country: current chess level, number of chess players, the country's economy, etc.

That said, assuming we're talking your country specifically i.e. Botswana, or more generally a developing country where chess isn't very widespread, the first thing I'd look into is the funding provided by FIDE's Planning and Development Comission (PDC). As of 2019 they offer up to 20,000 USD that can be used for purchasing chess equipment, organizing tournaments, etc.

In fact, as you can see on PDC's website, Botswana's funding request for 2019 has been approved. So you should check with your national federation and see how they plan to use the money.

Now if we're talking about a hypothetical situation where you can decide how the money would be used (e.g. for 2020), I'd suggest:

allocate a small part (say 20%) of the funding to improve the situation for existing players (including adults): purchase chess sets, organize free or cheap tournaments, organizer an arbiter  seminar, organize classes for intermediate/advanced players, or even provide coaching to players likely to play in the Olympiad. Note I'm not suggesting you do all of these, as $4000 isn't that much, just what you need the most.
allocate the bulk of it (say 80%) to the long term vision: for example, train chess instructors -- think Developmental Instructors in FIDE parlance, that is, people who can teach the rules and the basic of chess to beginners, not FIDE Senior Trainers -- and then provide cheap or free classes to children on weekends or after school.

Ideally you would institute chess classes in schools across the country (like in Armenia), but of course that's very hard to pull off. Still, you can use the Armenian case as an example. You want to convince parents and school teachers that spending time on chess is beneficial for kids, that it's associated with good outcomes. Example article.

You want to focus on elementary school children. It may sound harsh, but if your goal is to produce masters, starting at high school is a bit late.


Xiangqi symbols are now in Unicode 11.0, in the block Chess Symbols: U+1FA00–U+1FA6F.


Clarification on changed rules of getting rating from FIDE

If at least 4 of your opponents in that April 2014 FIDE rated tournament had FIDE ratings before the tournament and if you play another FIDE rated player in another FIDE rated tournament within 26 months of the April 2014 tournament and if you scored at least half a point out of all the games you played against FIDE rated opponents (so minimum of 0.5 / 5) then you should get a FIDE rating.

The key points are that you have to play at least 5 FIDE rated opponents (some of your opponents in April 2014 may have been unrated like you) and you have to get at least one draw against your FIDE rated opponents. They can't calculate a rating if you lose all your games.


Is CQL executable available anwhere online?

You can get it from the archive. Also the former rbnn website is preserved there.


Are there any online public chess databases I can upload my own games to?

I would suggest going to lichess.org and creating one or more studies for this. You can choose to make these public or private or only visible to those you give the link to. Within a study, you can upload the PGN of your games as separate chapters. You will need an account to make studies, but creating an account and using any of the study features is entirely free.

For each game, you can fill in as much or as little information about the players/situation as you want. Lichess studies also have advanced commentary features, so that you can describe your thoughts as well as annotate which moves you thought were interesting, blunders, etc. Personally, I find it useful to add variations I've found that I feel are worth further consideration - whether I found the variation during or after the game.

As an example, here is one study I made to contain the most interesting Tabletop Simulator games I've played, as well as my annotations of the games.


Which online chess websites allow you to download their games?

Chess-db allows you to search their database for a player and download all their games. For instance, if you search for Magnus Carlsen you get to his Chess-db profile page where there is a link which allows you to download all his games in their database. This is very useful for finding and studying the games of famous players or just for finding the games of an opponent so you can try and prepare against them.


What is the simplest method to win Queen vs Knight endgame?

I have looked at tablebases but the moves are somewhat bizarre

That's the problem with tablebases; they're efficient but they can't 'play' human chess. This particular endgame is one-sided enough that it's almost never required to play the best move.

Just drive the opponent's king to the edge of the board, as you would do with king+queen vs. king; just be careful that you don't end up in a knight fork. If the knight gets too far away from its king, you can probably fork it yourself after a few checks. Once on the edge of the board, the reduced mobility of the knight and mating threats will eventually lead to defeat.

Here is an example (from Shredder Chess):

The 'human' move here is Qg6+ (or Qa6+) followed by Kd5; it doesn't matter that Qe2, Qe3 and Qe4 are one move faster.


Bishop's opening - what's the point of 4. Qe2?

Black's main threat after 3... c6 is d5; it looks like Qe2 is an attempt to prevent that, by indirectly attacking pawn e5, even with check. However, I'm not so sure that it works as intended, because Black can play d5 anyway, e.g.

[FEN ""]
1. e4 e5 2. Bc4 Nf6 3. d3 c6 4. Qe2 d5! 5. exd5 cxd5 6. Bb5+ Nc6 7. Qxe5+ Be7 8. Nf3 O-O 9. Bxc6 bxc6 10. O-O Bd6

and Black's center control, slight development advantage and bishop pair provide more than enough compensation for the pawn.

I'd prefer a normal developing move (4. Nc3 or Nf3) instead of 4. Qe2.


How to get stockfish to play a selfmatch without clearing the hash table between games

I would like to keep the information saved in the hash memory. Is
  there a way to do that?

Yes, there is.

Stockfish is open source. So you can examine the code, modify it, recompile and rebuild.

What you need to do is:

Find where Stockfish creates and uses the cache
Modify the code to save the cache to disk when the game finishes
Modify the code to optionally (you won't want to do it for every new game) load the cache from disk for a new game


The answer depends on your strength. Unless you're a master, the answer is "no". Note that memorization of opening theory is easier the stronger of a player you are (as most moves will become "obvious", so you won't need to commit them to memory).
At this stage in your development as a chess player, the best thing you can probably do to help the study of openings is improving your chess skills (tactics and strategy).
But you can make the test yourself. Take a sample of your last few games and check how many of them would have had a different result if you knew by heart the lines you're about to study. The answer is probably "not many of them".
Ultimately it depends on what you want to achieve. If you want to master openings for the sake of mastering openings, then yes, you should memorize all of that. But odds are that what you're actually trying to improve is your overall chess strength, and there are definitely more effective ways to achieve that than rote memorization.


Well, he has to because there is no other option. The black Knight threatens to capture the white Queen, but also a 'sacrifice' on f3 which will eventually win the white Knight on c3.

[Title "White to move"]
[FEN "1r3rk1/1p4bp/p2p1q2/2pPn1p1/B1PnRp2/PPN2P1P/2QB2P1/3R2K1 w - - 5 27"]

1. Qb2? Ndxf3+ 2. gxf3 Nexf3+ 3. Kg2 Nxd2 4. Qxd2 Qxc3

This might not even be the best variation for Black. In any case, even after the sacrifice, White is still lost.


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

Black must submit to trading pieces or weaken his bishop.

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

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

Regarding other future ideas:

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


Intention of two moves of Topalov vs Anand

Alongside @IanBush's answer, the bishops prevent white's doubled rooks from penetrating black's camp:

[FEN ""]
[White "Anand"]
[Black "Topalov"]
[StartPly "48"]

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. g3 dxc4 5. Bg2 a6 6. Ne5 c5 7. Na3 cxd4 8. Naxc4 Bc5 9. O-O O-O 10. Bg5 h6 11. Bxf6 Qxf6 12. Nd3 Ba7 13. Qa4 Nc6 14. Rac1 e5 15. Bxc6 b5 16. Qc2 Qxc6 17. Ncxe5 Qe4 18. Qc6 Bb7 19. Qxe4 Bxe4 20. Rc2 Rfe8 21. Rfc1 f6 22. Nd7 Bf5 23. N7c5 Bb6 24. Nb7 Bd7 {[%draw full,c4,red][%draw full,c5,red][%draw full,c6,red][%draw full,c7,red][%draw full,c8,red][%draw arrow,b5,c4,green][%draw arrow,b6,c5,green][%draw arrow,b6,c7,green][%draw arrow,d7,c6,green][%draw arrow,d7,c8,green]} 25. Nf4 Rab8 26. Nd6 Re5 27. Nc8 Ba5 28. Nd3 Re8 29. Na7 Bb6 30. Nc6 Rb7 31. Ncb4 a5 32. Nd5 a4 33. Nxb6 Rxb6 34. Nc5 Bf5 35. Rd2 Rc6 36. b4 axb3 37. axb3 b4 38. Rxd4 Rxe2 39. Rxb4 Bh3 40. Rbc4 Rd6 41. Re4 Rb2 42. Ree1 Rdd2 43. Ne4 Rd4 44. Nc5 Rdd2 45. Ne4 Rd3 46. Rb1 Rdxb3 47. Nd2 Rb4 48. f3 g5 49. Rxb2 Rxb2 50. Rd1 Kf7 51. Kf2 h5 52. Ke3 Rc2 53. Ra1 Kg6 54. Ra6 Bf5 55. Rd6 Rc3+ 56. Kf2 Rc2 57. Ke3 Rc3+ 58. Kf2 Rc2  1/2-1/2


Solvable studies that computers fail to crack

Here is an outrageous mate in 57 puzzle which none of the top 3 engines are able to solve:

[fen "8/6pp/5p2/k7/3p4/1Q2p3/3prpp1/3Kbqrb w - - 0 1"]

1.Qc4 Kb6 2.Qd5 h6 3.Qc4 Ka5 4.Qb3 h5 5.Qc4 Kb6 6.Qd5 h4 7.Qc4 Ka5 8.Qb3 h3
9.Qc4 Kb6 10.Qd5 h2 11.Qc4 Ka5 12.Qb3 g6 13.Qc4 Kb6 14.Qd5 g5 15.Qc4 Ka5
16.Qb3 f5 17.Qc4 Kb6 18.Qb4+ Kc6 19.Qa5 f4 20.Qe5 g4 21.Qf5 Kd6 22.Qb5 f3
23.Qf5 Kc6 24.Qg5 Kd6 25.Qb5 d3 26.Qf5 Kc6 27.Qa5 Kd6 28.Qb5 Kc7 29.Qa6 Kb8
30.Qb6+ Ka8 31.Qc7 g3 32.Qc8+ Ka7 33.Qc6 Kb8 34.Qa6 Kc7 35.Qb5 Kc8 36.Qb6 Kd7
37.Qc5 Kd8 38.Qc6 Ke7 39.Qd5 Ke8 40.Qd6 Kf7 41.Qe5 Kf8 42.Qe6 Kg7 43.Qf5 Kh8
44.Qg5 Kh7 45.Qe5 Kg8 46.Qf6 Kh7 47.Qf8 Kg6 48.Qe7 Kh6 49.Qf7 Kg5 50.Qe6 Kh5
51.Qe8+ Kg4 52.Qf8 Kg5 53.Qf7 Kg4 54.Qf6 Kh5 55.Qg7 Kh4 56.Qg6 Kh3 57.Qh5#

Aside from the fact that the mating line is an absolute unit, an important reason why engines are unable to solve this is due to a technique called "Null move pruning".

Null move pruning assumes that playing no move is always worse than playing a move, which allows chess engines to search deeper by using this assumption to prune moves which are probably bad. However, because of this assumption, null move pruning is tactically vulnerable in zugzwang positions.

In the above position, black is pretty much perpetually in zugzwang, so null move pruning prevents most programs from being able to see how black's king is forced around the board. As a result, Houdini, Stockfish and Komodo all report draws.


I am 1400, how do I improve my positional play?

Positional thinking is more abstract than tactics.  If there could be an algorithm for positional thinking then positional thinking would be like tactical thinking and not something else.  However, there are thinking steps like noticing weak squares.

I suggest starting with a pawn structure book.  Soltis' "Pawn Structure Chess" is a classic and the book that changed my game all those years ago.  I really like "Chess Structures - A grandmaster guide" by Mauricio Flores Rios as well.

I believe it is best to start with looking at isolani positions as positional considerations are clear there, As I recall both books start with isolani.  After that skip to the chapters with the structures you play and start trying out the ideas in your games.

Think about what the ideal placement of your pieces would be in the position separate from how to get them there.

These books may have unintended consequences.  After I read "Pawn Structure Chess" I switched from 1.e4 to 1.d4 because I was more likely to get isolani and hanging pawns structures and outplay my opponents who didn't know about these things.


Antichess
Maybe Antichess is what you are looking for. The aim is to be the one to lose all the pieces first. And it's mandatory to eat. And of course kings are eaten. You can play under lichess.org such chess variant selecting a custom variant. You can see details here. But with children it's always better to play in person of course.
Legendary chess

I also recommend you Legendary chess, an application developed in Uruguay aimed for all ages and designed in a didactic way to learn chess basics step by step in a fun way with a storytelling scenario.
I don't remember exactly if there is a specific type of game where kings are eaten, but I bet you it's worth it to check the game and see.
In the site you can download the Spanish or English version. It's a Windows based application but you can always run it using wine if under Linux or Mac.


We're going to assume there is no hardware issue, as pointed by Tonny Ennis in his comment.

It's possible that a computer engine experiences a "bad" tournament, but it's extremely rare. When we say "bad", we don't mean collapsing like blundering pieces, it's more like not getting a good position suitable for the engine. Computer engine always play at a constant strength, dictated by the algorithm. They won't do anything other than what the algorithm tells it to do.

Let's give an example, it's well known Komodo is a better engine than Stockfish in a strategic position. If we randomly choose the openings in a match of four. We might see a closed position in three of those games. As expected, Komodo outplayed Stockfish in those three games. The final score would be 3-1 in favour of Komodo.

Does that mean Komodo is a much stronger engine than Stockfish? Probably not. Can we conclude Stockfish had a "bad day"? Maybe. But please remember the sample size is too small, what if we let them play more games? A typical computer chess tournament can have a match with over 1000 games. If we do it, we might see a very different result.

Conclusion: if we see a chess engine has a "bad day", usually it's because the sample size is too small or the testing condition is biased. The law of large number will erase unsystematic variation given enough sample size.


Some strange moves in Polgar vs Najer (2009)

The game Najer - Polgar, Richard Riordan GM Blitz, 2009 is from TWIC 767, along with the above sequence of moves. Sicilian Paulsen, White win, 78 moves. There are a large number of moveless games from the same tournament, so it looks like the event organisers had problems recording the game moves accurately.


Well, it is as simple as encasing a rook in a virtual box. We'll take the example and see it.

 [Date "????.??.??"]
 [Result "*"]
 [FEN "1k5r/1P3K2/8/2p2p2/7p/4P3/8/3R4 w - - 0 1"]

1.e4 fxe4 2.Kg7 Rh5 3.Kg6 Re5 4.Kf6 Re8 5.Kf7 Rh8 6.Kg7

We see that the rook is trapped inside a 4x4 box. Losing the rook means losing the position, and the only way not to lose it is to stay inside the box, and be constantly pushed by the king. If White doesn't do so, he is in serious trouble.


Touching a captured queen -- must I promote to it?

Yes, you should promote to a Queen forcibly. FIDE rules say that (emphasis mine):

4.4 If a player having the move:
[...]
4.4.4 promotes a pawn, the choice of the piece is finalised, when the piece has touched the square of promotion.

You placed the Queen in the promotion square, so you should promote to it.

However, I would suggest not to promote this way. Instead, you can move your pawn to the promotion square, then put the piece you want there.


The London 2018 World Chess Championship live coverage sources

I believe the live video footage is restricted to the official broadcast and you probably have to pay to get access to it.
The footage aside, the games will be broadcasted live on chess24 for free (even without an account) with a phenomenal team of commentators, namely, Peter Svidler, Sopiko Guramishvili, Alexander Grischuk, Anish Giri for the English commentary and there will also be separate commentaries in Spanish and German covering each round.

Here's their dedicated page to the WCC2018: https://chess24.com/en/wcc2018
And the featured page (including engine analysis etc): https://chess24.com/en/watch/live-tournaments/carlsen-caruana-world-chess-championship-2018/1/1/1


1. exd6 is bad because it opens up the bishop on g7. This would happen anyways, but it just made Black's job easier. It also completely opens the centre, which is not a good thing to do, especially when the king hasn't castled. Finally, it ignored the bishop that is indirectly threatening the Queen.
The correct response is 1... Nd4 which enables the Bishop to (directly threaten the queen) and places the knight in a central square, threatening at the same time the c2 pawn.
Now white has two options:

Qc4, which is a move that beginners would prefer as they cannot live without their queen. Black would reply with Nc2+ and after some moves here's how the position would look like:
[Variant "From Position"]
[FEN "r2qk2r/1p1bppbp/p1np2p1/4P2n/Q7/2N2N1P/PPP2PPB/R3KB1R w KQkq - 0 1"]

1. exd6 Nd4 2. Qc4 Nxc2+ 3. Kd1 Nxa1

Now White's position has multiple disadvantages:

The centre is open and the white king can't castle!
Material difference
The rook and the bishops aren't fully activated compared to the respective Black pieces.

Qxd4, a move that more experienced players would prefer. Here's how the position would look like after Nc2+, etc:
[Variant "From Position"]
[FEN "r2qk2r/1p1bppbp/p1np2p1/4P2n/Q7/2N2N1P/PPP2PPB/R3KB1R w KQkq - 0 1"]

1. exd6 Nd4 2. Qxd4 Bxd4 3. Nxd4 O-O 4. O-O-O

Now White is much better as:

They have castled.
Knights and the black-coloured bishop are active.
The white-coloured bishop will be developed probably in the next move, connecting the rooks at the same time.
They can attack the Black king (opposite castles)!
The dangerous black bishop on g7 is gone!
Bishop on d7 is inactive.

I believe you should try the move that will make your play easy later in the game and not Qxd4 just because the engine says so.


Improving board vision

When studying on your own, use a book with many diagrams so that you can check your visualisation regularly, e.g. Logical Chess: Move by Move by Irving Chernev
When studying with a partner, ask them to call out the moves of a variation then test your accuracy with questions like "what colour square is white's knight on?"

Source: Adapted from Studying Chess Made Easy by Andrew Soltis

Notes on board vision

I like to put a small (often 2 or 3 whole moves) variation into words as a mini-plan. E.g. "Moves 4-6: White gambits a pawn to develop the bishop". It doesn't have to be a deep analysis at all, just a narration to the moves to convert algebraic notation into English
"Long variation, wrong variation" - attributed to Bent Larsen in The Wisest Things Ever Said About Chess, by Andrew Soltis. In other words, visualising a variation 20 moves deep is unlikely to be beneficial
Don't get side tracked by sub variations
To make the visualisations easier, study endgames (i.e. fewer pieces to visualise)
"You can't see 64 squares at the same time" - attributed to Alfred Binet in The Wisest Things Ever Said About Chess, by Andrew Soltis. This is a natural limitation to human perception. Even looking at a board, you can only really see 12-16 squares at a time. Try to 'chunk' information together to reduce the strain. E.g. you can condense information into words like "White has a castled king behind a fianchetto"

Example with an opening that you want to learn using White

Suppose you want to visualise the opening 1. d4 d5 2. c4 dxc4 3. e4 e5 4. Nf3 Bb4+ 5. Bd2 Bxd2+ 6. Nbxd2 exd4 7. Bxc4 Nc6 8. O-O Qf6 9. e5 Qg6 10. Re1 Nge7 11. Nb3 O-O 12. Nfxd4

Let's visualise this step-by-step, checking your visualisation against the board in the spoiler tags below:

d4 d5 2. c4 dxc4 3. e4

    How close was your visualisation? The way I remember this is in words to remember the mini-plan: White gambits a pawn to get an ideal centre

PS. I've used a screenshot of the position from Ubisoft's Chessmaster, as the replayer can't be hidden in a spoiler tag: How to hide chessboard in a spoiler tag?.

3... e5 4. Nf3

    Black tries to demolish White's centre with the thematic ...e5 and White aims to protect the centre

4...Bb4+ 5. Bd2 Bxd2+ 6. Nbxd2

    Black develops a piece with tempo. White offers a trade to develop another piece that will end up on b3 to regain the gambit pawn

6...exd4 7. Bxc4 Nc6

    Black keeps hold of their extra pawn for the time being as White will have to spend a tempo to regain it

O-O Qf6 9. e5 Qg6 10. Re1

     White castles to safety whereas Black posts the Queen to the Kingside

10...Nge7 11. Nb3 O-O 12. Nfxd4

    Black castles away. White regains the pawn. Let the middlegame begin!

Source of variation and abridged analysis: Starting Out: Queen's Gambit Accepted by A. Raetsky and M. Chetverik

Example with an opening that you want to learn using Black

This is slightly harder as the board is now rotated both for practical play and in the spolier tags. Suppose you want to visualise the opening 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 dxc4 5. a4 Bf5 6. e3 e6 7. Bxc4 Bb4 8. O-O Nbd7 9. Qe2 Bg6 10. e4 O-O 11. Bd3 Bh5 12. e5 Nd5 13. Nxd5 cxd5 14. Qe3 Bg6

d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3

    White's most popular try in the Slav is to develop both knights early

4...dxc4 5. a4 Bf5 6. e3 e6 7. Bxc4

    Black develops the light square bishop and locks it outside the pawn chain

7...Bb4 8. O-O

    Black develops a piece. White breaks the pin.

8...Nbd7 9. Qe2 Bg6 10. e4 O-O

    White expands in the centre

Bd3 Bh5 12. e5 Nd5 13. Nxd5 cxd5

    The centre is closed

Qe3 Bg6

    Black offers to trade bad bishop for good. Let the middlegame begin!

Source of variation and abridged analysis: The Slav: Move by Move by Cyrus Lakdawala


What's the best time control to play online in order to improve?

This question will receive more opinionated answers regarding the time control, I will answer in perspective of an advanced beginner Chess player. Since you have said you are a beginner and never played in a tournament before, I would suggest you to have 1 hour or 45mins + 45sec increment time control. This is because of my previous answer here: Do longer games better your chances of honing chess skills?. Additionally:

When you engage yourself in a 1 hour time control chess game, you
are not under any pressure to make moves without calculation and
thus avoiding big blunders, this happens almost for everyone who
has not played against opponents much.
You are also open to various variations for a move, thus allowing to
think at least 3-4 moves ahead of the next move(visualizing).

  I like correspondence but sometimes I forget (over night) a bit the
  feeling of the game, lose the ideas or other stuff.

Yes, Correspondence games will tend you to lose track of your positions, tempo, tactics etc since it may take 1 or more than 1 day to make a move. Almost 20-30% of the time either me or my opponent will lose because of this, even though having an advantageous position. But my guess is Correspondence game is relative to your memory power.

But remember that you also need to concentrate on the skills by reading books, solving puzzles etc. Playing with opponents alone will not improve your game because online games are just application of your skills not development.


Arena: How to have the engine only analyze and let me play as both White and Black

In Arena 3.5, you can hit the "Edit" button next to "Analyze", and continue doing moves. In the edit mode, it does not try to do a move automatically. If you keep the "Analyze" button as pressed, then it will analyze both sides of the game. I think this is what you are looking for. See screenshot attached.


How should I improve my chesstempo tactics rating?

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.


Programmatic method to determine if a move is passive or aggressive

As described here the min-max algorithm is used in order to get the best strategy from any position in games, and therefore in chess. It uses tree ordering of the moves and each layer in the tree describes another player's move. The leaves at the bottom of the tree are the "values" gained from reaching this position with the sequence of moves from going down the tree. The algorithm assumes that the other player is playing his best possible moves also.
This algorithm was used for example in Deep Blue, but the problems were that the branching factor of each node in the tree gets huge after couple of moves. So this is very hard to calculate.

In the matter of your question, I don't think you could gain any knowledge about passive/agressive moves from min-max algorithm, as it only tells you the best moves (not knowing if it was passive or agressive).
I think a better approach to determine wether a move is agressive or passive will be tagging a large amount of moves in different positions in the game (with tags being 'passive'/'agressive') and training a Neural Network to determine if a new move that it never saw is passive or agressive.


A situation like this, with Black to move, is a win for White:

[FEN "8/8/8/3pP3/3P4/8/8/8 w - - 0 1"]

Why? Well consider the case where White has been skillful enough to take all of Black's pawns and promotes easily. By definition, Black has no legal moves. From a training game we do not want to teach that losing all material leads to a forced draw. That would be a poor lesson to learn for building a knowledge of King and Pawn endings on.

A note on passing. It seems that to implement this in a program, a player with no legal moves is forced to 'pass', just in case a situation arises that allows the 'stalemated' side to have a legal move later on.


I think I am the best person to answer this question as I have come across a similar kind of situation.

I would suggest you to first focus on whether you are losing your pieces by any opponent's strategy. Don't directly play with a high level opponent . For increasing your alertness, you can play chess on computer at a lower level and then gradually increase it once you start winning. 'Chess titans', for example, on Windows 7 is an excellent game to improve firstly your alertness, then the logical skills , and finally patience. Try to analyze what is happening on the board instead of narrowing your vision to 3-4 squares. This will greatly benefit you, my friend.

Now, we turn to logical skills. The most important thing here is to predict your opponent's move and develop your strategy to make him/her fall into your trap. Try to think simple rather than complicating situations. I would also suggest you to be calculative while playing. Here I mean to say that you should be able to think what is going to happen on the board after 2-3 moves. Thereafter, increase the count. I know that it is not possible in all situations, but try to exploit the situations where it works.

Finally,  patience. Patience , in any work, is the key to success. You can also calculate and plan your next moves while your opponent is planning his/her next move. Also you can try to be ahead of your opponent in calculations. For example , if your opponent has calculated what is going to happen in the next three moves, and if you have calculated upto 4 moves, then you have an edge over your opponent.

These simple techniques have helped me in overcoming my problems and I hope these will be beneficial for you too.


Did Leela Zero miss a win in this position?

For what that's worth, Stockfish 11 gives

Rh2 as +2.6
Kb4 as +2.2
Bxc7 as +0.6
other moves as 0.0

on my machine at depth 45 (will be updating this answer while it digs deeper). Rh2 and Kb4 occasionally switch positions as #1 and #2, so it's still unclear which one of these is truly best. Bxc7 surely isn't, however, at least if you believe Stockfish.
One important note: The top evaluation score has hovered between +2.0 and +2.6 since depth 15. Apparently, Stockfish has not found a way to substantially improve White's position (let alone win) in the last 30 plies. It's still possible that the game will end in a fortress situation with perfect play, and then Leela would in fact not have missed a win (despite having played a suboptimal move).

Edit:
At depth 54, it's

Rh2 as +3.9
Kb4 as +2.2
Bxc7 as +0.1
other moves as 0.0

Still not fully conclusive, but we're starting to get somewhere.
In any case, Bxc7 was certainly not the most optimal move that Leela could have played.


Not an expert but you can play against a "virgin" Leela by using one of the younger nets. For example in the first Leela test (the so-called training run) the strongest net was 11248. If you play against, e.g., net 00010, it'll be much weaker.

However, you can't train Leela by playing against it. You can play against the trained product, but you can't train Leela yourself. That's because Leela is supposed to learn entirely by self-play (that's why its full name is Leela Chess Zero - "Zero" for zero human knowledge).


Is studying computer games legal in correspondence chess?

On chess.com, use of books and game databases is allowed. Use of engines and tablebases is not. Your book is either a book or a game database and therefore fine.

There are also sites that don't allow any outside help (no books, no databases), and on the other hand the ICCF (the offiical FIDE-affiliated Correspondence Federation that is also completely online nowadays) does allow engine use, so it's best to always check the rules of the actual site you're using.


What would be the elo of a computer program that plays at random?

Right at the bottom of the Computer Chess Rating List for the 40/4 time control is Brutus RND, an engine that simply selects random legal moves.

http://www.computerchess.org.uk/ccrl/404/cgi/engine_details.cgi?print=Details&each_game=1&eng=Brutus%20RND#Brutus_RND

It has a rating of 205 (as of 6/6/2018). This is not a FIDE rating of course, but it is using the Elo system.

It has 0 wins, 242 losses and 64 draws. The draws are due to faulty programs that accidentally cause draws by repetition or occasionally stalemate, though they generally have a substantial material advantage when this occurs.

FIDE has a rating floor of 1000. Brutus RND would simply fail to establish a rating that high and would be unrated.

If we ignore the FIDE rating floor, it is possible to have a negative rating under the Elo system.

One point to mention is that FIDE uses a table to calculate rating changes and if the rating difference is greater than 735, no change occurs when the stronger player wins. This means Brutus could never have a rating of -5000 or anything like that because it would need to lose points to spectacularly incompetent players that would not be capable of delivering checkmate.

https://www.fide.com/component/handbook/?view=article&id=197

We are left guessing here. 1000 Elo rated players would be able to get Brutus's rating down to 265, but since there are no players with worse ratings, we cannot say exactly how much further they could push Brutus's rating down if they did exist.

I would guess that players that are 500 Elo or worse would have trouble delivering mate consistently, much like the faulty programs. Draws by 3-fold repetition or the 50 move rule are not automatic under FIDE rules and would only occur if Brutus claimed them. But a human could lose by running out of time, as well as drawing by accidental stalemate.

So I'm guessing somewhere in the -200 to 200 range if FIDE allowed ratings below 1000 and allowed Brutus to compete.


https://github.com/ddugovic/Stockfish

has what you want. Not an offical version, but should be stable for production.


Why do high level players memorize specific games?

Memorization is mostly a side effect, not the end goal. Top players can spend hours or days analyzing a single game to try to understand all of the instructive ideas. Memorization naturally flows from that.


Playing against an engine is definitely still good practice for your chess. You can typically scale the strength of the engine to make it harder or easier depending on your level. In my experience it tends to be bit boring since most engines tend to favour particular openings and a fairly aggressive style of play.  To combat this you can tell the engine to play a certain line, but this also takes some of the excitement out since you know in advance what the engine will play.

Aside from engines there are always plenty of online options to find a game. For example chess.com is a free site where you can play against basically any strength player. It also offers live matches as well as correspondence games. You can filter by ELO rating to find games against opponents who would suit your skills.


How about Philidor's mate?

http://ashbyivanhoechessclub.org.uk/juniors/checkmates/philidors-mate/

[Title "Philidor's Mate"]
    [FEN "1r4k1/3Q2pp/8/6N1/6K1/8/8/8 w - - 0 1"]

    1. Qe6+ Kh8 2. Nf7+ Kg8 3. Nh6+ Kh8 4. Qg8+ Rxg8 5. Nf7#

A well known pattern that involves a (sham) Queen sacrifice, a double-check, and a smothered mate delivered by the lowly Knight.


How do I check if a move is legal using Stockfish?

Stockfish assumes that all FEN positions you feed it are legal positions. If you feed it an illegal position and ask it to evaluate it, it will likely crash:

Stockfish 5 64 by Tord Romstad, Marco Costalba and Joona Kiiski
position fen 4k3/4p3/8/8/8/8/8/3KP3
go depth 14
Segmentation fault: 11

But you could use a Python library such as Chessnut to validate moves. Chessnut returns all legal moves with get_moves() and raises an InvalidMove exception if you pass an illegal move to apply_move(), as shown in their example:

from Chessnut import Game

chessgame = Game()
print chessgame  # 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1'

print chessgame.get_moves()
"""
['a2a3', 'a2a4', 'b2b3', 'b2b4', 'c2c3', 'c2c4', 'd2d3', 'd2d4', 'e2e3',
 'e2e4', 'f2f3', 'f2f4', 'g2g3', 'g2g4', 'h2h3', 'h2h4', 'b1c3', 'b1a3',
 'g1h3', 'g1f3']
"""

chessgame.apply_move('e2e4')  # succeeds!
print chessgame  # 'rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1'

chessgame.apply_move('e2e4')  # fails! (raises InvalidMove exception)

You could update the game each move with Chessnut, and only pass moves to Stockfish for evaluation if Chessnut says they're valid.


I simply do not agree with your computer there. It is probably a bit of the "horizon effect", which is when a computer plays a bad move because it puts the refutation beyond its ability to calculate, or "horizon".

White played this opening every passively, and really should be looking to break up black's center so he is not smothered, and b4 does not seem the way to do that. It is very short-sighted by white to try and keep c5, especially when it puts him behind in development. Per my computer, (quad-core 2.9Ghz with 24 GB of RAM), there are a bunch of moves there, and b4 is fourth on the list per Stockfish 10 on my computer. The other candidate moves are c4! (the best in my opinion), h3, and even Nb3 since e4 h3 is good for white.

6.b4?! Nxb4 5.Bb5? {h3, c4, or Rb1 are all still better per my beast) Nc6 6.h3 Bf3 7.Qf3 Bc5 8.c4 Nf6 and while white has some compensation for the pawn, it is not enough. Black is slightly better as white may win the pawn back soon, but black remains slightly better placed.

      [FEN ""]

     1. d4 d5 2. Nf3 c5 3. dxc5 Nc6 4. e3 Bg4 5. Nbd2 e5 6. b4?! (6. c4!) (6. h3) (6. Nb3 e4? 7. h3 Bxf3 8. gxf3 {and white is just a pawn up.}) Nxb4 7. Bb5+?! (7. c4!) (7. h3) (7. Rab1 {are all better}) Nc6 8. h3 Bxf3 9. Qxf3 Bxc5 10. c4 Nf6 11. cxd5 Qxd5 12. Qxd5 Nxd5 {Black's pieces are all very nicely placed here, and the Nd2 is passive.} 13. Bb2 O-O-O 14. Rc1? Bb4 {is the tactical justification.}


I setup the position using this FEN String

4k3/pppppppp/8/8/8/8/PPPPPPPP/4K3 w - - 0 1

Using a grid engine cluster with 24 nodes, each node having 16 cores at 3.2 Ghz with 60gb of ram

The engine used was Houdini 4 pro (allowing multiple cores)

After analyzing for several days ( 4 days 12 hours 2 minutes and 15 seconds to be precise)
the engine scored the position 0.00 flat with the suggested move line

1.d4 d5 2.Kd2 Kd7 3.Kd3 Kd6

Of course this is not nearly a bruteforce method, but i believe it is safe to say this is a draw. Of course @Rauan Sagit is correct. Correct play comes with intimate knowledge of pawn endings and will be even harder to achieve correct play against a skilled opponent


Which opening requires the longest amount of chess moves?

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'}


Claude Bloodgood, the popularizer of the Grob (1. g4), must be far and away the most famous. At one stage his USCF rating was second only to Gata Kamsky! It doesn't get much worse than murdering your own mother.


King's Gambit is not really a horrible opening. Just after all the theory that has been amassed since Spassky has shown that it loses white's advantage. There are other openings that create a good amount of initiative without the possibility of falling into a losing position.


How to break through a stubborn Semi-Slav?

The position you are looking at is indeed very common in the semi-Slav defense and the solid control of the d5 square is exactly the underlying idea for Black, often after having played ...dxc4 at some point in the opening. Looking at White's piece placement, in particular at the e pawn on e3 and the White dark squared bishop on the king's side, this seems to have originated from the classic Moscow variation, namely

[fen ""]
[Event "Merano defense, Moscow variation"]

1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.Bg5 h6 6.Bh4 dxc4

At this point White has to play aggressively to avoid Black keeping both the pawn and maintaining the initiative: the standard continuation for White is 7.e4 (that you have not played) to threaten the knight on f6 and force Black to play 7...g5 and weaken their king's side. Playing 7.e3 instead gives Black the possibility to continue developing their pieces calmly; they played possibly something like 7...Be7 but could have played instead 7...b5, pushing on the queen's side and threatening ...b4 at some point.

However, given your position on the board, White usually pursues the plan of the minority attack on the queen's side rather than going for control of the d5 square, pushing the a and b pawns to threaten b5 or c6. In order to do so it is fundamental to give rook support on the c-file with something like 0-0 followed by Rfc1. Stockfish gives the following idea, after castling:

[fen ""]
[Event "Merano defense, Moscow variation: Stockfish analysis"]

1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.Bg5 h6 6.Bh4 dxc4 7.e3 Be7 8.Bxc4 Na6 9.Bd3 O-O 10. Qc2 Nc7 11.O-O b6 12.Rfc1 Bb7 13.Ne5 Rc8 14.a3 Nce8 15.b4

and White can play trying to break on the b-c files somehow. Perhaps you want to play 12.Rfd1 instead, to avoid ...c5; dxc5 and already having control of the d-file instead.

As an example let us have a look at a famous match Topalov-Kramink, one of the many regarding (semi)-Slav variations and Queen's gambit declined as in the fashion of two amongst the most productive players of those lines:

[fen ""]
[Event "Corus"]
[Site "Wijk aan Zee NED"]
[Date "2008.01.22"]
[EventDate "?"]
[Round "9"]
[Result "1-0"]
[White "Veselin Topalov"]
[Black "Vladimir Kramnik"]
[ECO "D44"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "89"]

1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6 5.Bg5 h6 6.Bh4 dxc4 7.e4 g5
8.Bg3 b5 9.Be2 Bb7 10.O-O Nbd7 11.Ne5 Bg7 12.Nxf7 Kxf7 13.e5
Nd5 14.Ne4 Ke7 15.Nd6 Qb6 16.Bg4 Raf8 17.Qc2 Qxd4 18.Qg6 Qxg4
19.Qxg7+ Kd8 20.Nxb7+ Kc8 21.a4 b4 22.Rac1 c3 23.bxc3 b3 24.c4
Rfg8 25.Nd6+ Kc7 26.Qf7 Rf8 27.cxd5 Rxf7 28.Rxc6+ Kb8 29.Nxf7
Re8 30.Nd6 Rh8 31.Rc4 Qe2 32.dxe6 Nb6 33.Rb4 Ka8 34.e7 Nd5
35.Rxb3 Nxe7 36.Rfb1 Nd5 37.h3 h5 38.Nf7 Rc8 39.e6 a6 40.Nxg5
h4 41.Bd6 Rg8 42.R3b2 Qd3 43.e7 Nf6 44.Be5 Nd7 45.Ne6 1-0


Who did Nigel Short really play on the ICC in 2001 when he thought he was playing Fischer?

Nobody knows who he played, because nobody has come forward to take credit; however, some chess sleuths compared the moves against various engines and found that there was considerable evidence to support a particular engine (I believe it was called "blitz tiger") as the mysterious Fischer.  Because of the incident where Short chatted with Fischer, there must have been a human behind the account as well (many accounts on the ICC are run entirely by computers without any human interaction at all).  The ICC can probably do some user profiling to figure out who the player is either by comparing the location/IP/e-mail to another user or by doing some internet forensics based on information they gathered from the incident.  However, it seems like they either don't care or if they did find out, they don't want to share (based on what xaisoft said) so it will probably always be a mystery.  And, to be honest, it's a better story that way, and because all this is is a good story, that's a good thing.


Updated.

You need to play in FIDE-rated events. Even playing one game would get you in the system (meaning they would be aware of your existence), but you would not be officially rated until you played at least 5 games against FIDE-rated players, during the course of 26 months, and be rated over 1000. It no longer appears as if you need and minimum score.

For more of the detailed points, check out the FIDE Handbook here, specifically under section 7.


While it is extremely difficult for a human to beat the top chess engines, many of the mobile engines (like Driodfish) are still beatable.

I will consider Driodfish 1.53 since that's the one currently installed on my Android phone and is similar to the one the OP is using.

Engines are very good at tactics, so humans cannot realistically hope to beat them there. However, engines don't "understand" strategy. The top engines can cope with this because they simply think way too deep and can tactically compensate for lack of strategic understanding. They also have good evaluation functions. However, the weaker mobile engines still lack in this area.

So the way to beat these engines is to achieve those kind of positions where strategically you have an edge at the cost of some temporary tactical disadvantage (like material). Engines can often be lured into such positions. For instance, consider this game I just played with Droidfish 1.53. At the cost of a pawn (temporary tactical disadvantage), I was able to secure a very strong advantage for myself many moves later. The computer failed to see this when it went for the material advantage -

[FEN ""]
[White "Wes"]
[Black "Droidfish 1.53"]

1. d4 d5 2. c4 c6 3. Nc3 Nf6 4. e3 e6 5. Nf3 Nbd7 6. Qc2 Bd6 7. g4 Nxg4
8. Rg1 h5 9. h3 Qf6 10. Be2 Nh6 11. e4 Bb4 12. Bg5 Qg6 13. Bd3 dxc4
14. Bxc4 Qh7 15. O-O f6 16. Bxe6 fxg6 17. Nxg5 Qg6 18. f4 Bxc3
19. bxc3 Qf6 20. f5 Nf8 21. e5 Qe7 22. Bxc8 Rxc8

Droidfish 1.53 itself now evaluates this position as a clear advantage for White.

As great a player as Garry Kasparov himself employed this strategy in some of his games against the top engines of that time.

Garry Kasparov vs Deep Junior 2003, Round 1, 1-0

  [FEN ""]
  [White "Garry Kasparov"]
  [Black "Deep Junior"]
  [Date "2003"]

  1. d4 d5 2. c4 c6 3. Nc3 Nf6 4. e3 e6 5. Nf3 Nbd7 6. Qc2 Bd6 7. g4 dc4
  8. Bc4 b6 9. e4 e5 10. g5 Nh5 11. Be3 O-O 12. O-O-O Qc7 13. d5 b5
  14. dc6 bc4 15. Nb5 Qc6 16. Nd6 Bb7 17. Qc3 Rae8 18. Ne8 Re8 19. Rhe1 Qb5
  20. Nd2 Rc8 21. Kb1 Nf8 22. Ka1 Ng6 23. Rc1 Ba6 24. b3 cb3 25. Qb3 Ra8
  26. Qb5 Bb5 27. Rc7

Garry Kasparov vs X3D Fritz 2003, Round 1 1/2-1/2

  [FEN ""]
  [White "Garry Kasparov"]
  [Black "X3D Fritz"]
  [Date "2003"]

   1. Nf3 d5 2. c4 c6 3. d4 Nf6 4. Nc3 e6 5. e3 Nbd7 6. Qc2 Bd6 7. g4 Bb4
   8. Bd2 Qe7 9. Rg1 Bc3 10. Bc3 Ne4 11. O-O-O Qf6 12. Be2 Nf2 13. Rdf1 Ne4
   14. Bb4 c5 15. cd5 ed5 16. dc5 Qe7 17. Nd4 O-O 18. Nf5 Qe5 19. c6 bc6
   20. Bf8 Kf8 21. Ng3 Ndc5 22. Ne4 Ne4 23. Bd3 Be6 24. Be4 de4 25. Rf4 Bd5
   26. Qc5 Kg8 27. Rgf1 Rb8 28. R1f2 Qc7 29. Rc2 Qd7 30. h4 Qd8 31. g5 Ba2
   32. Re4 Qd3 33. Rd4 Qe3 34. Rcd2 Qe1 35. Rd1 Qe3 36. R1d2 Qg1


What are these chess.com figures from my English Opening game?

I believe you mean this (correct me if wrong):

This refers to time in seconds that it took to complete a move. So in this case (my game), it took White 2.5 seconds to make a  move, and 0.9 seconds for Black to respond. Then it took 19.7 seconds for White to make a move, and 1 second for Black to respond.
In your case, it took White 9.6 seconds to make a move, and Black 5.8 seconds to respond.


Why is the algebraic notation not just two numbers?

I believe that it is more of a historic thing where chess players went from descriptive to algebraic notation, really because strong players started adopting algebraic notation. Admittedly, using 2 numbers would probably be just as easy to use once you get use to it.
Infact, ICCF(international correspondence chess federation) uses such coordinate systems in order not to confuse people from different countries who would use different alphabets for algebraic notation.


How should black meet 2.d4 in the Sicilian Defense?

In classical chess openings, the first thing white tries to do is build a pawn center with pawns on both e4 and d4. So the first goal of 1.e4 is to follow up with 2.d4, and the first goal of 1.d4 is to follow up with 2.e4. Of course, there is an opponent, so usually white has to shift plans quite quickly, but that's the classical theory.

Black can react in several different ways. If he attacks pawn e4 right now, then white can't really move 2.d4; that's what 1...d5 and 1...Nf6 do. 1...e6 and 1...c6 prepare 2...d5, so that black also gets a foothold in the center. Moves like 1...g6 let white go right ahead and hope that black will be able to sabotage white's center later and use the empty space left behind. 1...e5 puts black's own pawn in the center, makes 2.d4 exd4 possible and opens up lines for the bishop and queen: the classical best move.

1...c5 does slightly less than 1...e5: if white does play d4, black can chop off the pawn, and it opens up a diagonal for the queen, but no minor pieces are freed. The point is that that e-pawn is a center pawn, and therefore more valuable than the c-pawn: if black can trade c for d, he'll have one more pawn in the center. It's a very long term idea and he'll suffer first because he is behind in development, but the extra center pawn is helpful in defence and if he survives he'll probably have a better pawn structure.

So the whole idea of the opening is to play 2...cxd4 after 1.e4 c5 2.d4. 2...e6 would be followed by 3.d5, when black can't trade c for d anymore and white gets a slight space advantage.

This also explains the three main ways to play white against the Sicilian: fight it head on by still going for d4 (either 2.d4 or 2.Nf3 3.d4) and try to destroy black using the development advantage, prepare d4 with 2.c3 ("the only move that takes the Sicilian seriously", van der Sterren), or all the other plans that use d3 instead of d4, trying to show that white can do without d4 and that therefore 1...c5 is silly.


How to play chess against a large number of players simultaneously?


Strong chess program for GNU/Linux with a command line interface?

I wrote about Stockfish in the link you had. I don't see there is any engine better than that.


What are signs of achieving Master strength?

If a player is truly stronger than you independent of his current form, he is able to outplay you even if you don't overlook a single important tactic. If he is in bad form he will probably overlook tactics himself and let you back into the game, but you will still be outplayed in the stretches between his little blunders.

Once you don't have this feeling anymore of drifting into trouble without knowing why when playing against master players, and once you are able to just outplay weaker players by hand, you can be pretty sure that you have reached a master's level of understanding. Your Elo should follow suit.


The more pieces on the board,  the more powerful the center pawns. This is typical for most opening and middlegame positions. The most convenient place for pieces to travel is usually through the center of the board, and the center pawns help to control that area.

The less pieces on the board, the more powerful the wing pawns. Less pieces on the board means less need to control pieces travelling through the center. A passed wing pawn is harder to stop than a passed center pawn. Your opponent needs to go further to the edge to defend against it. This can really stretch out and discoordinate his pieces if he has to defend against another weakness on the other side of the board. The outside passed pawn is like a decoy.

Generally speaking, you can think of Center pawns becoming weaker and weaker as pieces are exchanged, and wing pawns stronger the closer you reach an endgame.


Attack those pawns on side where is no rook. Once he makes a hole, get your queen on his backs. This way you will be able to grab like 2~ I'd say. Then run with a pawn on a free file.

1. e3/e4 - Nc6 2. Qh5-h6 3. Qg4-g6 4. Qf4-h5 5. Qh6
just an example


Is it worth it to transition into more open lines when one is used to closed, positional games?

From a strong expert:

Just because I find open games to be more fun, I would suggest playing more open games.  Also a variety of openings will expand your knowledge.  (Looking at your tournament history, you may already have enough knowledge.)  Just like you don't quit smoking in one day, don't switch to overly aggressive opening.  Try the Scotch, Vienna, or Giuoco Piano.  These openings requires the learning of more opening traps, but they should improve your quality of play.

Assuming that you have the time to invest in studying an opening, learn the common positions and plans.  If after trying this style you feel uncomfortable, go back to playing the closed/positional games.  If the game is not fun, it is not worth playing.

When I reached expert level, I switched to a more positional game because I thought this is what was supposed to happen.  I lost many games because I hid my talent.

Some GM said that he switched to d4 because he got lazy as he got old.  Anna Zatonskih said that with d4, White can make more mistakes before losing the game.  You could be hanging on to the safety of known avenues.


You have some options.  You could abandon 7. Nbd2 because it allows 7. ... Ng4; the standard choices in the main line are 7. Qe1, 7. c3, and 7. Nc3, much like the regular Leningrad Dutch.  If Black plays Ng4 while you still have e3 covered by the Bc1, you can simply proceed with your plan to push e2-e4, and maybe later kick the knight with h2-h3 to get an attack going on the kingside.  Just make sure to keep an eye out for tactics on the a7-g1 diagonal as long as Black has a knight on g4; Bird's Opening can get ugly for White fast if you miss seeing a tactic.  You'll still need to pay attention to e3; Black's main try in the strongest lines is to play d5-d4, possibly following up with Nd5, and eventually you'll need to be prepared to play against that.  If your opponents are still gifting you e6 setups though, that might be a ways off.
In the specific position you've shown with Black's lackluster e6 setup, you have the option of going straight for 7. e4 as @bof and @pulsar512b discussed, but that idea won't ordinarily be available if Black plays more demanding lines.
If you're dead set on making 7. Nbd2 work instead, then 7. ... Ng4 8. Nb3 doesn't look like the absolute end of the world to me, but the positions aren't pleasant and Black is calling the shots.


How many FIDE rated games are played per year?

I was surprised not to be able to easily find this statistic.

The information is available with quite a lot of work from data which FIDE makes available on its website. The key page is the Ratings Download page. If you are an arbiter and you use a FIDE approved pairing program (e.g. Swiss Manager or Vega) then when you click the button to auto-magically update FIDE player details and ratings it will start by downloading and processing one of the files linked to on this page.
You don't have to be a pairing program to download files from this page. Anybody can do it. For me there are 4 important files -

Download full list of players (not rated included) ... XML format
Download STANDARD rating list ... XML format
Download RAPID rating list ... XML format
Download BLITZ rating list ... XML format

These files are updated by FIDE on an almost daily basis and so reflect data only for the last month. If you want historic data then towards the bottom of the page there is an option where you can select a period and see and download files from that period.
Most months I download the first file above and process it to extract these kinds of statistics in the same sort of way, I guess, as Kaspars Migla who runs the chessratings.top website referenced in the FIDE post in the other answer. If I forget then I download the 3 separate files from the archive. This is obviously more work but the big file isn't available in the archive.
From what Kaspars Migla says:

It is a very rough estimation because only games played by rated players in classical chess are taken into account.

it looks like he just downloads the standard file whereas I download the file with all data including rapid, blitz and Online Arena. So, his figures are likely to be slightly different from mine.
There are a number of things to note.

File 1 (full list of players) is more than sum of files 2, 3, and 4. It contains unrated players and ratings for FIDE's Online Arena.
For each player and rating type, along with the player's rating and K factor, it gives the number of rated games played that player in the period.
Because FIDE update the files more than once during the month you will get slightly different data if you download on different days.
Because these game numbers are for rated games played by a rated player they include each game played between two rated players twice, once for each player.
Similarly, they also include games played between a rated player and a previously unrated player who gains a rating in this period only once. The newly rated player has the game counted in their count, because it was played against a rated player, but the previously rated player doesn't because for them the game was not against a rated player. Hence odd numbers are possible in a sum which is roughly twice the number of rated games played.

How many FIDE rated games are played around the world each year?

OK, so now for the numbers. As I said I download and process the big file for all the players containing all the data rather than the three separate files for standard, rapid and blitz only. I've run some queries on my resulting database.
For each year the four numbers are sum(standard game count), sum(rapid game count), sum(blitz game count), (sum of sums)/2
As explained above the sum(standard game counts) is actually roughly twice the sum of actual FIDE rated games because each game is counted for each player.
As it happens the total number of FIDE rated games did exceed 3 million in 2019 for the first time although just over half were standard and the others were rapid and blitz.
I've given figures going back to 2011, the year before FIDE started rating rapid and blitz.
Year Standard   Rapid   Blitz   Total
2019 3015776    1684486 1338912 3019587
2018 2886482    1382951 1063591 2666512
2017 2786351    1150926 958753  2448015
2016 2629805    907642  785846  2161646
2015 2349963    631590  589853  1785703
2014 2022154    467333  426370  1457928
2013 1873662    313977  338094  1262866
2012 1689346    97722   117587  952327
2011 1569389    0   0   784694


You have choices:

i. Kibitz, implemented features are

Playing and observing chess games on FICS
Observing multiple games
Chat with other users on FICS
Support for chess variants including "Bughouse" and "Crazyhouse"

ii. Raptor, FICS desktop client for Mac

iii. Jin, which is Java based and can be executed on a Mac also.

iv. XBoard, a multi platform solution!

and such a pity that you can't try BabasChess (maybe you can use a emulator to execute it on your Mac)


Can a rook put an opponent's king in check as a result of castling?

Yes, of course he can; you're indeed in check. Imagine if checks didn't exist--then on the next move, if your king hasn't moved, he could just take your king with his rook.


What are some good books or articles on how to play coffeehouse chess?

Maybe it's not exactly "coffeehouse" but Simon Webb's excellent Chess for Tigers is all about finding what works rather than looking for objectively best moves. From page 2 of the 2nd edition:

  Next time you sit down to play a match, ask yourself what is your aim in playing. Are you aiming to play the best moves? Or are you playing to win? There is a difference. Many players aim merely to play the best moves, objectively speaking. They never succeed, of course, but that doesn't stop them trying. But chess is not a science — it's a game, a struggle between two mortals who make mistakes, deceive themselves and each other, get tired, allow themselves to be distracted, and altogether have no hope of attaining perfection at the chess-board. If you want to become a Tiger, you must forget about playing the best moves and concentrate on winning.


Doesn't that pretty much turn the opening into a real gambit?

No.

  Black can now hold on to the c-file pawn since the usual trap (with Qf3) is no longer possible and b4 can be safely played by Black to prop up the c-file pawn.

No he can not. White will regain the pawn and get huge advantage.

Here are the most relevant lines, the rest can be easily found with an engine:

[fen ""]

1.d4 d5 2.c4 dxc4 3.Nf3 b5? 4.a4 c6 5.axb5 cxb5 6.b3 cxb3 ( 6...Be6 7.bxc4 Bxc4 ( 7...bxc4 8.e4 Qc7 9.Qa4+ Qd7 10.Bxc4 ) 8.Na3 Qc7 9.Nxc4 bxc4 ( 9...Qxc4 10.e3 Qc6 11.Ne5! Qb6 12.Qb3+/- ) 10.Qa4+ Nd7 11.e3 c3 12.Bb5 e6 13.Ne5 Ngf6 14.Bc6 Rd8 15.Qxa7+/- ) 7.Qxb3 Qb6 8.e3 b4 ( 8...Bd7 9.Ne5 e6 10.Nxd7 Nxd7 11.Qxb5+/- ) 9.Qd5! Bb7 ( 9...Qb7? 10.Bb5+!+- ) ( 9...Nc6 10.Ne5+-) 10.Bb5+ Bc6 ( 10...Nc6? 11.Ne5+- ) 11.Ne5+-

Best regards.


How do you document your opening repertoire on a mac?

A lichess study would be a good way to do this.


The captures in atomic chess work as follows:

The captured and capturing piece always die.
Then, anything around the capture square that's not a pawn dies.

For en passant, the capture square is the "bypassed" square of the double pawn move.
See https://lichess.org/variant/atomic or https://illion-atomic.netlify.app/atomic-rules/


Chess Position Trainer on Linux or Minimax on Linux

Sorry, no. Chess Position Trainer only runs on Windows 7, 8, and 10.

See the system requirements here.

You could consider a virtual machine running Windows on a Linux host, but it will not run natively.


I would say you are wasting your own time. Black could have built a d5-e5 center with two bishops on d6 and e6 in your setup. Even in you own line, Black has all the winning chances due to weaker White king.

You are giving Black the development for free. Your opening idea won’t work against any decent player.

Please study normal openings.


Can I download early versions of Leela chess zero?

For early versions, the lczero project's download page refers you to the lc0 releases available on GitHub. For versions from 2018, you can go the lczero repository on GitHub.
Note that while the downloads from from the former repository (lc0) provide both Windows builds and source code, the older releases from 2018 (lczero) give you only source code that you need to compile by yourself.


Why does castling in the Four Knights: Double Spanish opening inadvertantly stop Bxc3?

One hundred years ago grandmasters, even the great Capablanca, were given to making sweeping judgments about opening positions without supporting evidence, often condemning moves that have been shown to be quite playable. In fact 5...Bxc3 is now considered a "book" move, though 5...O-O is probably slightly better. And as to 5.d3 making the exchange good, after 5.d3 5...Bxc3 is now considered roughly equal to other reasonable moves like 5...O-O or 5...d6.
BTW the Four Knights Game is often casually dismissed as a "drawish" opening, again without supporting evidence. If you study it and try it you'll find that many opponents who expect the more usual 3.Bb5 or 3.Bc4 are unprepared for it.


Short answer: No such thing

Long answer: Contempt factor noted by @Tony is close but not exactly what you are looking for. It is a scaling constant for changing the evaluation score. It is a simple technique for avoiding early draws against apparently weaker opponents, or to prefer draws versus stronger opponents otherwise.

Other techniques that can influence the engine:

Run multi-pv analysis, and choose a move from the principal variations
Randomly add noise to the search
Slow down the engine
Fixed depth or fixed number of nodes
......

But they are still not what you are looking for, because chess engine always assume a perfect opponent. Why? That's because the alpha-beta framework always prune bad moves. The framework doesn't allow for dirty cheap tricks.

Let's think about it. It's actually not trivial to code an engine that makes dirty tricks. How does an engine know the tricky would work for a human player? Maybe it's just a gross blunder?

It's hard to to tell the engine:

When to swindle vs when to defend
How a human player would fall into a trap
Stupid blunder vs great swindle


Is it rude to ask my opponent to resign an online game when they have
  a lost endgame?

Yes, it is rude, although you are in good company. In one Olympiad Victor Korchnoi is alleged to have asked his opponent - "Do you speak English?" When they said "Yes" he replied "Then please resign". I may be misquoting. He may not have said "please" :-)

Strictly speaking today what Korchnoi did is not allowed in over the board chess because it is disturbing the opponent. In online chess, however, trash talking is more acceptable because the opponent can always mute by switching off chat.


What is the name of this pawn structure for black, with doubled c and f pawns?

There is no special name for the structure you show where black has doubled c and f pawns.


Can someone explain the positional advantages for white?

You evaluate the position statically which only rarely works. As for your static evaluation you are correct, that the black bishop is stronger and that the pawns take some squares on the fifth rank. On the other hand, white has two active rooks vs one black rook.Stockfish gives a static evaluation for this position of +0.76 if white is to move and +0.5 if it is black's move. So statically it is roughly equal with a slight advantage for white.

However, such static evaluation is only really useful (if at all) in quiet and/or closed positions. In open positions like the one here, where there are concrete ideas, the static evaluation does not tell you anything. You should look at least a couple of moves deep to see what plans white and black could follow.

White has at least three obvious ideas: play against the a5 pawn, against the week pawns on e6 and f6 or directly against the black king.

Black has no obvious plan other than exchanging pieces and (if veryvery lucky enter the white position with heavy pieces.

Concretely to your question:

Black’s bishop has more scope than the white one: True, the black bishop has more scope, but there is not much to do along that diagonal.

White has some isolated pawns: Neither player has isolated pawns. Please check what an isolated pawn is.

the Black pawns rule the 5th rank.S: They cover squares on the 5th rank, but hey that's just the 5th rank, i.e., on the black side of the board (in the starting position the pawns rule the 6th rank....). Also (and much more relevant here), since the pawns are next to each other they don't support each other anymore and the pawns on e6 and f6 are weaknesses. Typically, building such horizontal line of pawns to gain space is a good thing to do in the opening phase, when the pawns can be supported by pieces. Towards the endgame such pawn lines can often become weaknesses.

Assuming it is white to move,my engine says about +3, (which means white is clearly winning) and gives the following line: 1. Rxd8 Qxd8 (or Rxd8 which is slightly worse) 2. e5

If black captures fxe5 or allows white to capture exf6, he will end up with a very weak isolated pawn on e6 (in addition to the weak pawn on a5) and a rather open king (ideas with Qe5, Rc7 or h5 look very scary for black).

If black closes the position with f5, the engine likes to go for the a5 pawn by exchanging queens with Qg5. Another viable option could be h5 with an attack on the king. In any case, black is left with weak pawns on e6 and a5.

So in summary, it is basically black's weak pawns that make the difference.

If in the initial position you...

move the pawn from f6 to f7, the evaluation improves for black to +2, because the pawn structure is much more stable.
remove all the pawns on the a and b files, the evaluation improves for black to +1 only.


The shape of the pieces is a standard Staunton chess set. However, the marbled material makes it look rather unusual. I am not up on the rules about color use, but I have my doubts that it would be permitted in tournament use if one of the players objected.


Is it playable in Blitz?  GM Nakamura played 2. Qh5 against GM Sasikiran in 2005 who responded with 2... Nc6. Nakamura lost due to an error in the middle game.

Here's the Nakamura game.  It follows the mainline 2... Nc6 but shows, to my surprise, White has a good game, contrary to everything I ever heard about moving the Queen too early.

[FEN ""]
1.e4 e5 2.Qh5 Nc6 3.Bc4 g6 4.Qf3 Nf6 5.Ne2 Bg7 6.Nbc3 d6 7.d3 Bg4 8.Qg3 Qd7 9.f3 Be6 10.Bg5 Nh5 11.Qh4 h6 12.Be3 Na5 13.Bb3 Nxb3 14.axb3 a6 15.d4 Qe7 16.Qf2 exd4 17.Bxd4 Nf6 18.O-O-O O-O-O 19.Nf4 Rhg8 20.Rhe1 Kb8 21.Kb1 g5 22.Nfe2 Rge8 23.g4 Qf8 24.Ng3 Nd7 25.Be3 Qh8 26.Nge2 Be5 27.h4 Qg7 28.Rh1 Nf6 29.Bd4 Nd7 30.Qe3 Qf6 31.hxg5 hxg5 32.Bxe5 Qxe5 33.Rh5 Rg8 34.Nd5 Rde8 35.Qc1 Qg7 36.Ne3 Nf6 37.Rh2 Rh8 38.Rg2 Nd7 39.Nd4 Rh3 40.c4 Qf6 41.Rf2 Reh8 42.b4 Qe5 43.c5 dxc5 44.bxc5 Nxc5 45.Qc3 f6 46.Rc2 Na4 47.Qb4 Bd7 48.Nb3 Rh1 49.Rxh1 Rxh1+ 50.Ka2 Nb6 51.Qf8+ Qe8 52.Qxe8+ Bxe8 53.Nc5 Nd7 54.Nxd7+ Bxd7 55.Kb3 Re1 56.Rc3 Be6+ 57.Kc2 Re2+ 58.Kc1 a5 59.Nc2 Rf2 60.Nd4 Bd7 61.Rc5 b6 62.Rd5 Kc8 63.e5 fxe5 64.Rxe5 c5 65.Nb3 Rf1+ 66.Kd2 a4 67.Nxc5 bxc5 68.Rxc5+ Kb7 69.Rxg5 Rxf3 70.Rd5 Be6 71.Rd3 Rf1 72.Rg3 Rf2+ 73.Kc3 Kb6 74.Kb4 Rf4+ 75.Ka3 Kb5 76.Re3 Bd5 77.Rd3 Bc4 78.Re3 Rd4 79.g5 Rd1 80.b3 axb3 81.Re8 Ra1+ 82.Kb2 Ra2+ 83.Kc3 Rc2+ 84.Kd4 b2 85.Rb8+ Ka4 86.g6 Bb5 87.g7 b1=Q 0-1

The opening has a few names.  Most are not complementary.  One less caustic name is the Wayward Queen Attack.  It is classified technically as the C20: KP, Patzer opening.  This opening is considered 'irregular' and does not have a more specific classification. The sub-variation we're interested in, even moreso.

There are no masters game in my database that include 2... Nf6.  There are many amateur games, but sometimes these are games by USCF C-players which does not help us here.  Out of those games, however, Black is heavily favored.  This does not mean the variation is fatal for White, per se.  It could mean that White has to play better or be better prepared than Black.

This means that, for blitz, this continuation is splendid for either side.

Here's Stockfish's continuation after 15 minutes. Stockfish rates the position above as White being up 1/3 of a pawn. I am sure this is very much within the "error noise".  I would not really trust it beyond 2 or 3 moves but it shows the gist.

[FEN "rnbqk2r/ppppbppp/5n2/4Q3/4P3/8/PPPP1PPP/RNB1KBNR w KQkq - 0 1"]

1.Qf4 Nc6 2.e5 Nd5 3.Qe4 Nb6 4.Bb5 O-O 5.Nf3 d5 6.Qe2 Nb4 7.d4 Bg4 8.a3 a6 9.Ba4 Nxa4  10.axb4 Qd7 11.c3 f6 12.O-O fxe5 13.dxe5 Bxf3 14.gxf3 Nb6 15.f4 Qf5 16.Na3 *

Okay, what you see here is a pretty sharp continuation.  Again, superb for a prepared blitz player.

Here's a game at 1 minute per side.  If the result of this game differs from the result of a game with longer controls, perhaps we can deduce that one side has a subjectively easier game and thus an advantage.

[FEN "rnbqk2r/ppppbppp/5n2/4Q3/4P3/8/PPPP1PPP/RNB1KBNR w KQkq - 0 3"]

3.Qf4 O-O 4.Nc3 Bd6 5.Qh4 Nc6 6.d4 Nxd4 7.Bd3 Re8 8.Be3 Be5 9.O-O-O Nc6 10.Nce2 d6 11.f4 Ng4 12.Qxd8 Nxd8 13.Bd2 Bf6 14.Rf1 Be7 15.Nf3 Ne6 16.Nc3 Nc5 17.Bc4 c6 18.h3 Nh6 19.g4 b5 20.Nxb5 cxb5 21.Bxb5 Bb7 22.Bxe8 Rxe8 23.g5 Nxe4 24.gxh6 Ng3 25.Rhg1 Ne2+ 26.Kd1 Nxg1 27.Nxg1 Bf6 28.b3 Bg2 29.Rf2 Bc6 30.Rf1 gxh6 31.Ne2 Kh8 32.Ng3 Bg2 33.Re1 Rxe1+ 34.Bxe1 Bxh3 35.c4 Kg7 36.Nh5+ Kg6 37.Nxf6 Kxf6 38.Ke2 Bd7 39.Bb4 Ke6 40.Kf3 h5 41.Kg3 d5 42.cxd5+ Kxd5 43.Bc3 Bg4 44.Be5 a6 45.Kh4 Be2 46.Kg5 Ke4 47.a3 Bg4 48.b4 Bd1 49.Bd6 Kd4 50.Be7 Bg4 51.Bc5+ *

A typical alien-looking game, where each move is coldly logical. It's looking drawish with Black having less than a pawn advantage according to Stockfish.  But the game is no 'trade the pieces' draw; I'd wager there are many ways to lose this.

Next will be a game at 10 minutes per move.

Edit - my machine crashed twice yesterday while grinding through the game at 10 minutes per move.  It was about halfway through the last time I looked.  It found 2 moves that could be improved by .3 pts or more.  I'm not going to rerun it.


What is the name of chess format in which one player has only pawns, no king?

It is either Horde or the very similar Dunsany's chess: 32 pawns against the regular chess army.


Is there a hash or string that represents a stockfish evaluation of a position to a certain depth?

I doubt that can be possible.

An analysis to a certain depth contains the generated position tree and the calculated values, which is quickly becoming a very large amount of data.
For depth 10, you probably need several megabytes of memory to represent the analysis result in a way that it could be used to continue searching deeper. There is simply no way to compress this into a small hash or anything else.


There no certain answer to your question. It depends.

An opening with a "drawish reputation" usually turns against the player who chooses it without having a deep knowledge of the opening itself.

That said, I think that both of these, if understood, can be a very hard match against a White player who desperately tries to win. But they're not easy to play.

In my opinion, as a 1. e4 player (so, with the "opponent's point of view"), the Berlin is quite solid but harder to play: Black has to find suitable squares for his pieces, and must play carefully to avoid White attacks.

As White, I am comfortable playing against the Petroff: for Black it's a little bit easier to play, but has many traps, and usually the Knight becomes an easy target for White pieces. Black will lose tempo while trying to defend it.

In conclusion, don't choose an opening only for its "drawish" reputation: this may be true only at higher levels, where players know very well almost every opening. At lower levels, on the contrary, the player who relies on a specific "drawish opening" in order to draw a game will find himself in trouble more often than not.


Castling is done by moving the King two squares towards the Rook, and then placing the Rook on the square that the King skipped over. In order to castle, all of the following must be true.

It's your turn.
The squares between your King and your Rook are all unoccupied.
You have not yet moved your King.
You have not yet moved the Rook that you are using to castle.
You are not currently in check.
You will not end up in check.
The square that your King passes through must not be under attack by an enemy piece (in other words, your King will not pass through check).


Steely, grim perseverance in the face of certain destruction

As this question highlights, it can become problematic if you don't even feel like you have a hope of winning a single game. Where's the fun in that? In my opinion, chess should be played first and foremost because it is fun. It isn't very fun never to feel the satisfaction of playing a nice winning combination against an opponent.

I think it's important for chess improvement to have fun while dealing with chess, and thus some success is needed. Otherwise it all becomes a chore, which will impede development in the long run. Therefore, I don't think it's
advisable to play against stockfish for practice, unless it's training of some particular technique. Furthermore, stockfish training (i.e playing games against stockfish) will never really be applicable in regular games, as humans cannot, and will not even try to, play like the top computers.

However, facing strong opponents is a crucial component to improving. The ideal opponent is in my view somebody with a strength about 200-400 rating points above oneself. Then they will most likely beat you, and highlight the mistakes you make which makes them easier for you to discover and correct for future games. But you still have a realistic chance of scoring. You will have to struggle though, and really push yourself not to get blown off the board.

If you don't play stronger opponents, you will never improve very much. Why? Because there simply is no need for improvement then!


What is the best move for White in this position?

First, how would you evaluate the position?  This should help you come up with a plan and thus the moves to consider. It seems you are randomly selecting moves, which you would then calculate the consequences.

Black has serious weaknesses you can think to exploit.  How about those c-pawns?  c5 looks very weak.  And White's Knights are probably drooling over all the holes they can hop on.

B-c1-a3xc5 looks like the juiciest plan (someday getting a Knight to d6 is attractive too).  You just have to make sure Black can't get away with something like c5-c4.   Black will have to do something desperate for counter-play.

A dream line would go:  1.Bc1 Re8 2.Ba3 Rb5 3.Nfd2 Bf8 4.Nc4 Rd8 5.Nd6 Ra5 6.Qf6


What is the theory if black goes 4 Nxc4 in evan's gambit?

You probably mean 4...Nxb4.
White will play 5.c3, and there is probably nothing better than 5...Nc6; so it boils down to being the same as 4...Bxb4 5.c3 Bc5.
[FEN ""]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Nxb4 5.c3 Nc6


You use neither.

You run your search to collect the best PV from your triangular table. This gives you your best variation. Then you exclude this best move and run another search to get the best PV from your triangular table. This gives you your second best variation. And so on.


Select and deselect piece to move mode in Arena

Although there may be a solution for your problem, I suggest you get used to it instead, as it follows the official laws of chess and deters you from doing otherwise.

  4.3 Except as providedin Article 4.2, if the player having the move deliberately touches on the chessboard:

  a. one or more of his own pieces, he must move the first piece touched which can be moved

Good practice for visualization and proper chess etiquette.

Source: https://www.fide.com/component/handbook/?id=124&view=article


If both players simultaneously resign, what is the result of the game?

In such a hypothetical situation, I wouldn't be surprised if both players lose and will be eliminated from the tournament's results, thereby not qualifying for the consolation prize. It's entirely possible to classify their behaviour as unsportsmanlike and discrediting the game of chess, which is against the FIDE Code of Ethics.

  2.2.10
  In addition, disciplinary action in accordance with this Code of Ethics will be taken in cases of occurrences which cause the game of chess, FIDE or its federations to appear in an unjustifiable unfavorable light and in this way damage its reputation.


What is the main idea in this winning endgame?

Interesting position;
Activating your king I don't believe is the answer. I think your first goal is try and force the the c2 bishop off the board. corner the black king and create as many potential promotion threats (a , e and h files particularly)
I played the position out for a while on a few variations and will attach the cleanest variant;
I see the main objectives for white though is to try and lock blacks king on the right hand side and or rear of the board, try and remove potential promotion threats. Black black bishop is relatively harmless and is tied to the c5 pawn. Preventing the c5 pawn from promoting or moving will also keep the b4 bishop from being active in the game. Slowly whittle down the right side of the board which creates to many promotion opportunities that overwhelms blacks defenses.
[Title "White to move"]
[fen "B7/3R2p1/4pk2/2p2p2/Pb3P1p/4P1P1/2b4P/6K1 w - - 0 42"]

1. Bc6 h3 2. Kf2 g5 3. Rb7 gxf4 4. gxf4 Kg6 5. Be8+ Kh6 6.Rb6 Kg7 7. Rxe6 Kf8

Key Moves:
gxf4 by capturing towards the center, you keep the b4 bishop not being able to cause any impact to whites pawns on the E through H files. Any attempts will result in a loss of material. In addition to this the c2 bishop is quite an inactive piece in this position
[Title "White to move"]
[fen "4Bk2/8/4R3/2p2p2/Pb3P2/4P2p/2b2K1P/8 w - - 0 8"]

8. Bd7 Bb3 9. Ra6 Bd5 10. Be6 Be4 11. Ra7 Ke8 12. a5 Bd3 13. a6 Bxa6 14. Rxa6 Bc3 15. Rc6 Bb4 16. Bxf5 Kf8 17. Bxh3 Kg7

Key Moves
Be6 support by the rook on a6, white has no means of capturing the without trading out its only useful bishop. The bishop is also somewhat "shepherding" the king with the a6 rook. It is also positioned attacking the c8-e3 diagonal poised to take out blacks pawns and threaten promotion.
Ra7 Locks the king to the d8 , e8 , f8 squares.
a6 forces black to capture with the bishop otherwise white can easily promote to queen and then mate.
To summarize

Blacks b4 bishop is tied to the c5 pawn. Blacks only potential promotion threat can be largely ignored.
Keep up pressure. This is preventing Black from doing any meaningful development. Black is forced to move and lose pieces in this position.
Prevent Black from activating their king.


Learning my favorite grandmaster games by heart

It won't help much. You won't understand why they are choosing the moves they are making. The easiest and fastest way to improve is to go to your local chess club. They will pair you with opponents of your skill level. The better players will help you.


Where to download a 6 man Nalimov endgame tablebase?

From the ICCF site:
Players who wish to have access to the 7 men tablebases may purchase any of the following programs: ChessOK Aquarium 2017, Houdini Aquarium 2017, Houdini PRO Aquarium 2017, Chess Assistant 17 with Houdini 5  and Chess Assistant 17 PRO with Houdini 5 PRO.

Free Android application
One more way to access 7-man tablebases without having a key is to use Android application.

Search for Lomonosov Tablebases or use https://play.google.com/store/apps/details?id=com.convekta.android.lomonosovtb

Alternatively, if players only want access to 6 men tablebases they may visit this page to use the 6-piece Nalimov tablebases: http://chessok.com/?page_id=361


What do you do when you put your king in check and you don’t realise?

You noticed immediately, which makes it very easy because in this case the rules are the same (apart from time penalty) for all forms of chess. In the first instance you have to take back the illegal move and make a legal move. If possible you have to move the piece you touched. So, if your king could legally move to another square that's the move you would have to make. If it could legally move to several squares then you could choose between them.

For a first offence your opponent gains time on the clock. At blitz this is 1 minute and for standard and rapid it is 2 minutes. A second offence loses the game. But note that these penalties only apply if you pressed the clock before your opponent noticed and told you. If you did not press the clock then there is no penalty. You just have to make a legal move with the piece you touched.

The rules governing this are the FIDE Laws of Chess. This is what they have to say:

  7.5.1  An illegal move is completed once the player has pressed his clock. If during a game it is found that an illegal move has been
  completed, the position immediately before the irregularity shall be
  reinstated. If the position immediately before the irregularity cannot
  be determined, the game shall continue from the last identifiable
  position prior to the irregularity. Articles 4.3 and 4.7 apply to the
  move replacing the illegal move. The game shall then continue from
  this reinstated position.

  7.5.5   After the action taken under Article 7.5.1, 7.5.2, 7.5.3 or 7.5.4 for the first completed illegal move by a player, the arbiter shall give two minutes extra time to his opponent; for the second
  completed illegal move by the same player the arbiter shall declare
  the game lost by this player. However, 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.

Those are the rules for standard time control where the moves are being written. Because the moves are being written down it doesn't matter if the illegal move is noticed after several more moves were played, you still have to go back to the position when the illegal move was made and make a legal move instead.

For rapid and blitz this usually isn't possible and so the rules say that the illegal move has to be flagged before the next move. Appendix A in the Laws deals with rapid and the rule says:

  A.4.2 If the arbiter observes an action taken under Article 7.5.1,
  7.5.2, 7.5.3 or 7.5.4, he shall act according to Article 7.5.5, provided the opponent has not made his next move. If the arbiter does
  not intervene, the opponent is entitled to claim, provided the
  opponent has not made his next move. If the opponent does not claim
  and the arbiter does not intervene, the illegal move shall stand and
  the game shall continue. Once the opponent has made his next move, an
  illegal move cannot be corrected unless this is agreed by the players
  without intervention of the arbiter.

Appendix B deals with blitz and that says:

  B.4 Otherwise, play shall be governed by the Rapid chess Laws as in
  Article A.2 and A.4.

So, the rules are the same as for rapid, but for the penalties:

  B.2 The penalties mentioned in Articles 7 and 9 of the Competition
  Rules shall be one minute instead of two minutes.


Statistical Right Handedness Bias in Move Selection?

I found no scientific literature on hand bias in Chess on Google Scholar.

From the comments there doesn't seem to be any database analysis supporting a theory of hand bias, e.g.

  Statistically, White is more likely to castle queenside than Black. Since 90-93% of people are right-handed, this is contrary to your theory.

Accredited to @Mike Jones.

Additionally, I haven't found any anecdotal evidence of hand biased in my own chess books. E.g. there is no mention of it in the 'Psychology' or 'Tournament Tactics' sections of The Wisest Things Ever Said About Chess.


I found a few in an article on chessworld.com called "31 Great Chess Quotes from Garry Kasparov."

“When your house is on fire, you can’t be bothered with the neighbors. Or, as we say in chess, if your King is under attack, don’t worry about losing a pawn on the queenside.”

“If you wish to succeed, you must brave the risk of failure.”

“The highest art of the chessplayer lies in not allowing your opponent to show you what he can do.”


In the USA, we have to notate our games. This would likely prevent issues where an opponent claimed a draw fraudulently.

I played tournament chess for years and never knew of a single instance of the sort of fraud and cheating that you mention.  (My point is that I have not had to deal with it so others may have more germane experience.)

EDIT - good observation by @ghotir.  If you agree to a result, write the result, sign the scoresheets, and do not reset the board until this has been done. Even so you both have the scoresheets.  That's how it happens at tournaments.


Should white be able to win this endgame?

White's main threat is c5, which forces a pawn exchange and a passed pawn with king covering queening squares. The bishop is covering the g pawn.

Should black force an exchange of that pawn, white's rook could go to e5 and capture the d pawn, allowing a double passed pawn.

If black defends c5, white first move his king to b4 to cover the next 2 pawn squares, then force black to zugzuang(by moving rook to a file) which forces black to stop defending c5 or move the rook.

If black moves rook to e5, putting pressure on the bishop, white pins black's knight and therefore forces a minor piece exchange, with a more active king, which will then go on and promote pawns.

If black stops pressuring the bishop, the endgame should be easily winnable.

As for Ke7, idea would be the same

For moves that does not either pressurise c5 or protects d6, force an exchange on c5 and you can win easily


It's a silly trick.  The board is upside-down!  The bottom left square is h8, and the top right is a1.  A legal move for white (but not a mate in 1) would be 1. e8=Q.  Look at it upside-down for a minute, readjust your perception of which squares are controlled by pawns, and you'll soon find a mate in 1.


Which titled players (IM or GM) have also been successful politicians?

Dana Reizniece-Ozola holds the title of Woman Grandmaster (2001) and is a politician who served as Minister of Economics (2014–2016) and Minister of Finance (2016–2019) of the Republic of Latvia. In the Olympiad of 2016, she beat Hou Yifan.

Perhaps not a minister, but in chess he reached the absolute top: former World Champion Anatoly Karpov. He's member of the Russian parliament since 2005.

Another example is GM Viktorija Čmilytė. She was European women's champion in 2011 and a member of the Lithuanian parliament since 2015.

One more example is GM Loek Van Wely. He was rated among the world's top ten in 2001 with a rating of 2714. He's elected for the Dutch parliament in 2019, so it's still hard to say whether he's a successful or unsuccesful politician.


What is the best Black reply to 1. d4 in regards to getting an open game?

1...d5. Tarrasch defense and, in general, c5 ideas practically always give an open game. As long as you can get in the move c5 with Black, you have excellent practical chances of achieving an open game.

Some sample variations -

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

  1. d4 d5 2. c4 (2. Nc3 Nf6 3. Bg5 (3. Bf4 e6 4. Nf3 c5) 3... c5)
 (2. Nf3 e6 3. g3 (3. e3 c5) 3... c5 4. Bg2 Nc6 5. O-O Nf6 6. c4 dxc4
  7. Qa4 Bd7 8. Qxc4 b5 9. Qd3 Rc8) 2... e6 3. Nc3 c5 4. cxd5
 (4. Nf3 Nf6 5. e3 Nc6 6. a3 a6 7. dxc5 Bxc5 8. b4 Bd6) 4... exd5
  5. Nf3 Nc6 6. g3 Nf6 7. Bg2 Be7 8. O-O O-O 9. Bg5 cxd4 10. Nxd4 h6 11. Be3 Re8


Programs like ChessBase, ChessPad, Scid vs. PC, and Lucas Chess all let you highlight squares & draw arrows on the board. You can then just record what you're doing using regular screen recording software like the excellent oCam.

Edit: I've created a video showing how to use Lucas Chess to create instructional chess videos. View it here. (YouTube)


Not any good books, as most use tactics as the only guide. however you can practice yourself.  Solitaire chess, where you try to guess the move--and the reason--before reading it from the annotated game, is the best practice, yet has the major flaw of not considering every style of play.

A must read for everyone is Nimzovitsch's My System.  Botvinnik's game are useful for showing how to maneuver, which is useful for exploiting positional mistakes.

Thinking Techniques (written by Dr. Ferguson ~ 1982)

BEFORE EVERY MOVE...THINK:

What new threat(s) has my opponent's last move created?  How can I answer it(them)?
Is my King safe?  Is my opponent threatening to checkmate in the next few moves?  Can I checkmate my opponent?
What threats can I set up?  How?
Have I seen this position or a similar one before?
If so:  who stands better, and what is the best plan for continuing?
If not:  what are the outstanding features and elements of this position, and what plan(s) and method(s) of achieving it are available?
What is my plan?  What specific position would I like to obtain?  How can I achieve my goal? How can I improve my position?
Which move is best?  Can I capture material without penalty? Can I employ an tactical device?
Is it safe to move my piece to the square I'm thinking about?
Did I remember to start my opponent's clock and write down my move?

Not as useful as I hoped, but without a game example or more definite  problems, it's hard to provide a specific answer.


What's the correct way to calculate centipawn loss?

No. Your assumption is based on searching everything up to depth D, but no modern chess engine would do that. It's complicated to explain, but fair to assume only some subtrees up to depth D are explored. The other trees got "cut" off for various reasons, most likely they are not good.

Chess programming is all about skipping the search tree accurately. The conditions could depend on the depth to the root, previously visited nodes, and many others. As you make a move on the board, all parameters change, even the cache for keeping the transposition table change. Trees that are previously visited may now be skipped, and vice versa. The change of information in the transposition table could have a significant impact in the new search path.

  it will be negative if the engine prefers the player's move to its initial choice after seeing one ply farther in the line beginning with the player's move. Is this expected and acceptable?

Anything can happen. The difference can be positive, negative, or remain unchanged.


No, this is not a rule in chess. There are plenty of games where one king reaches its 8th rank, and the game continues, with all three results still possible. Here are the Fide rules


In online correspondence chess, are the ratings adjustments based on the pre- or post-game ratings?

Every site that I have seen uses the rating at the end of the game.


Longest sequence of moves by one player with the same piece?

The record for most consecutive moves by a piece in a FIDE rated (it's FIDE at the least) event is 80 moves by a rook, starting on move 67. It happened in the game Yueh Wei Po- Arora during the 37th Chess Olympiad. It was a draw in the end. This record is on Tim Krabbe's page for chess records of course.

 [Title "Yueh Wei Po-Arora, 37th Chess Olympiad, Turin Italy, 6/2/2006"]
 [FEN ""]
 [startply "133"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 Bg4 6. Be2 O-O 7. O-O Bxf3 8. Bxf3 c6 9. Be3 Nbd7 10. Qd2 Qc7 11. a4 a5 12. Be2 e5 13. dxe5 Nxe5 14. f4 Neg4 15. Bxg4 Nxg4 16. Bd4 f5 17. Bxg7 Kxg7 18. Qd4+ Kg8 19. Rad1 Rad8 20. exf5 gxf5 21. h3 Nf6 22. Rfe1 d5 23. cxd5 Nxd5 24. Nxd5 Rxd5 25. Qc4 Qf7 26. Rxd5 cxd5 27. Qd4 Rc8 28. Rd1 Rc4 29. Qxd5 Qxd5 30. Rxd5 Rxf4 31. Rxa5 Rb4 32. Rb5 Rxa4 33. Rxb7 Rd4 34. Kf2 Rd3 35. Ke2 Rg3 36. Kf2 Rd3 37. b4 Rb3 38. b5 Kh8 39. b6 Kg8 40. g3 h6 41. h4 Kh8 42. Rb8+ Kg7 43. b7 Kh7 44. Ke2 Kg7 45. Kd2 Kh7 46. Kc2 Rb4 47. Kc3 Rb1 48. Kc4 Kg7 49. Kd5 Rb3 50. Ke5 Rb5+ 51. Kd6 Rb3 52. Kc7 Rc3+ 53. Kb6 Rb3+ 54. Kc5 Rb1 55. Kc4 Rb2 56. Kc3 Rb1 57. Kc2 Rb4 58. Kc3 Rb1 59. Kd4 Rb2 60. Ke5 Rb5+ 61. Ke6 Kh7 62. Kf6 h5 63. Kg5 Kg7 64. Kxh5 f4+ 65. Kg4 fxg3 66. Kxg3 Kh7 67. Kg4 Rb4+ 68. Kg5 Rb5+ 69. Kf6 Rb6+ 70. Ke7 Rb4 71. Kd7 Rb2 72. Kc7 Rc2+ 73. Kb6 Rb2+ 74. Kc5 Rb1 75. Kc4 Rb2 76. Kc3 Rb1 77. Kc2 Rb4 78. Kc3 Rb1 79. Kd4 Rb2 80. Ke5 Rb1 81. Kf6 Rb6+ 82. Kf7 Rb1 83. Ke7 Re1+ 84. Kd6 Rd1+ 85. Kc5 Rc1+ 86. Kb4 Rb1+ 87. Ka5 Ra1+ 88. Kb4 Rb1+ 89. Ka3 Rb5 90. Ka2 Rb4 91. Ka3 Rb1 92. Ka4 Rb2 93. Ka5 Rb1 94. Ka6 Ra1+ 95. Kb6 Rb1+ 96. Kc7 Rc1+ 97. Kd8 Rd1+ 98. Ke8 Re1+ 99. Kf8 Rf1+ 100. Ke7 Re1+ 101. Kf6 Rf1+ 102. Kg5 Rb1 103. Kf6 Rb6+ 104. Kg5 Rb5+ 105. Kg4 Rb4+ 106. Kf3 Rb3+ 107. Ke4 Rb4+ 108. Ke5 Rb1 109. Kd4 Rb2 110. Kc3 Rb6 111. Kc4 Rb1 112. Kd4 Rb4+ 113. Kc5 Rb2 114. h5 Rb1 115. Kd5 Rb2 116. Ke6 Rb1 117. Kf6 Rb6+ 118. Kg5 Rb5+ 119. Kg4 Rb4+ 120. Kf5 Rb5+ 121. Kf4 Rb4+ 122. Kg3 Rb3+ 123. Kf2 Rb2+ 124. Ke3 Rb3+ 125. Ke2 Rb2+ 126. Kd3 Rb3+ 127. Kd4 Rb4+ 128. Kc3 Rb1 129. Kd4 Rb2 130. Ke3 Rb1 131. Kf2 Rb2+ 132. Kf3 Rb3+ 133. Ke2 Rb2+ 134. Kd3 Rb1 135. Kd4 Rb2 136. Ke5 Rb1 137. Kf6 Rb6+ 138. Kf5 Rb5+ 139. Ke6 Rb4 140. Rf8 Rxb7 141. Rf5 Ra7 142. Kf6 Rb7 143. Kg5 Ra7 144. h6 Rb7 145. Kh5 Ra7 146. Rg5 Rb7 147. Rc6 1/2-1/2


Is a bishop less than half the value of a bishop pair?

A bishop pair is rarely worth more than a pawn. That would mean you're willing to sacrifice a pawn to obtain the bishop pair.

The value of pieces depends on what those pieces can accomplish, not just how many squares they control.

knight/bishop = 3 pawns because at worst, a minor piece can usually sacrifice itself for 2 pawns. So it's worth at least 2 pawns, but minor pieces are more useful than 2 pawns, and can potentially win another pawn, so theoreticians estimate its value at 3 pawns. 4 pawns is pushing it, it's less likely a minor piece can force exchanging itself for a value of 4 pawns.

The same can be said for the rook, a rook can usually exchange itself for a minor piece and pawn at any time, so it's worth at least 4 points. But the minor piece can't force the rook to make this exchange as easily as the rook can.  5 points is a fair estimation. Similar things can be said for the bishop pair and queen. It's the potential for these pieces to win more material than they can be exchanged for that increases its practical value.


What openings should be played in a simul?

I've always heard that person giving a simul should strive for quiet positions, where they can use their superior understanding and not have to calculate much, and his opponents should strive for the opposite: complex, tactical positions. Even GMs can miscalculate while giving a simul, since they have so little time per move, and so many boards to worry about. This makes sense to me, and I think this holds regardless whether strength of participants is known in advance.

Having said that, there are some crazy Morphy and Alekhine tactical wins in simuls, even blindfold simuls.


Instead of giving checkmate, I gave stalemate. Why?

No; for checkmate, the king must be in check, i.e. attacked by one of your pieces. This isn't the case in the position you posted, but if you were to move, you'd be able to force mate in two:

[FEN "8/8/4K3/8/6R1/2k5/7R/1R1R4 w - - 0 1"]

1. Rh3+ Kc2 2. Rg2#

Actually, you don't need that many rooks to checkmate. A lone king and rook will be enough; the procedure is explained in this Wikipedia article.


Sacrificing Bishop for Two Pawns against Queenside Castling

I'd argue you never want to play such a bishop sacrifice if your opponent is willing to take it.

Therefore, I think your question is rather “when can I take the undefended ♟ a7”.

To answer this, I'd say you need

Either a defense on the bishop (with a rook or a knight)
Or a crushing attack if you can sacrifice it. A queen around, or a rook coming on the open c-file, with pieces supporting that are mandatory. If the king can't easily escape to e8, that's better.
Nothing better to do. That's just a far pawn, and it takes 2 tempi to take eat if you want to save your bishop. Your opponent need not take bigger of an advantage in the meantime, that you could defend from before taking the pawn.