Has anyone other than GM Axel Smith and GM Hans Tikkanen had success improving their chess through the "Woodpecker Method"? The Woodpecker Method was introduced in the book Pump Up Your Rating (Google Books) by GM Axel Smith (FIDE), who was inspired by a training method used by GM Hans Tikkanen (FIDE), who used it to improve his chess.  A subsequent book The Woodpecker Method (Google Books) was published by the two GMs.

A description of this method is given in Brian Towers's answer, but it involves repeatedly solving tactics problems (not only what's the best move? But, also, what are the critical lines?).

There's some debate online (see e.g. chess.com) as to whether this helped Axel Smith improve, or if this was attributable to other aspects of his chess training.  Hence my question:

Question: Has anyone other than GM Axel Smith and GM Hans Tikkanen had success improving their chess through the "Woodpecker Method"?

In the chapter Woodpecker History from the book The Woodpecker Method, Hans Tikkanen says this:

  I was obviously asked by many people about what I had done to finally
  take the step from IM to GM. I described the method and my rationale
  for adopting it, and several others decided to give it a go. One
  Swedish trainer has apparently invited his students in the north of
  our country to work dedicatedly on the method for a while.

But, tantalisingly, he does not name names.


Why are English setups with g3 like the Catalan considered solid for White, while the Sicilian Dragon is risky for Black? I know that the Sicilian Dragon is considered very risky for Black if White knows what they're doing; they can go for the Yugoslav Attack setup, play h4-h5 to break open the h-file, try and exchange the fianchettoed bishop, etc. in an attempt to checkmate Black. English setups with g3 seem to have a similar structure but with colors reversed, so why is e.g. the Catalan considered so solid for White?

I think the answer is threefold:
First white usually has a development advantage in the Catalan because he moves first, so any Black attack would not be so dangerous.
Second, white has a space advantage in the Catalan with his pawn on d4, while in the Dragon black's d-pawn is on d6.
Third, and probably very important, is the fact that it is not easy for black to exchange the fianchetto Bishop on g2 on the Catalan, because he generally plays ...e6, making it very hard or impossible to play Be6(f5, g4) Qd7 and Bh3. In the Dragon Be3, Qd2 and Bh6 is generaly much easier to achieve, compromising the castled position of the black King.


What is the best chess piece? I'm new to western chess and am still learning the rules and how the pieces perform.

What is generally considered the best chess piece?

The queen has the most squares available to land on, I recommend you get well acquainted with the rules of the game in the official FIDE Handbook


Why is taking the e4 Pawn considered risky here? [FEN ""]
1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bc4 e6 7.Bb3 b5 8.f4?!

Almost nobody takes the e4 Pawn with 8...b4, and then N or B takes e4. Is there a clear refutation by White, or is it simply considered "risky" play by Black? After all, he is taking a strong central pawn.

Sorry for the lack of a board here, I will learn how to paste boards here soon.

8.f4 b4 9.Na4 (Nce2 is reasonable too) Nxe4, one might ask, what has white got?

O-O and black has serious issues developing as the amazing line given by the comp (I wouldnt have seen this line) :

10...Be7 11. f5 e5 12.Bxf7+! Kxf7 13.Ne6 Kg8 ( Qd7 14.Qg4 wins material back, Bxe6 fxe6 Kxe6 Qg4+ is no good, Ke8 Qd5 wins material back with decisive effect.)

14.Qd5 and Qh5 g6 (h6 Kh7 Qf5- Qxe4 wins) Qf3 win back material.

The safest line that black can go for is 10..Nf6 imo, just retreating, but white has interesting play with 10.O-O Nf6 Qf3 d5 (what else?) 12.f5 (full throttle) e5 (what else?) 13.Re1 or 13.Bg5!? are interesting for white.

The lines go on and on, but white has very direct, brutal play with the pieces working with the f-pawn in some shape or form. Whether it works or not is another matter.

After all, f4 isnt the main line, O-O is. Diagrams below are me visualizing my lines stated above.

[FEN ""]
1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bc4 e6 7.Bb3 b5 8.f4?! b4 9.Na4 Nxe4 10. O-O Be7 11. f5 e5 12.Bxf7+! Kxf7 13.Ne6 Bxe6 14.fxe6 Kg8 15.Qd5

[FEN ""]
1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bc4 e6 7.Bb3 b5 8.f4?! b4 9.Na4 Nxe4 10. O-O Nf6 11.Qf3 d5 12.f5 e5 13.Re1 e4!?

It's probably better it opt for something safe.


Recommendations for kids sites I am a teacher, and don’t really play much. My students like chess and I want to send them to some safe chess sites for kids. Recommendations?

I have a few.

Chess Kid is part of chess.com, which is the largest chess site in the world. There are both free and paid memberships.

Another great site is ChessKids Academy. They have come very basic lessons for newcomers, and the best thing is that it is free.

Kid Chess also has some nice material that is free.

All of these sites have components for both the players, and the adults, who are helping them.


Can one side force a loss in regular chess? Chess is unsolved, so there is no known optimal strategy for one side to force a win or a draw.

However, is there an optimal strategy to lose? Consider a variant where checkmate results in a loss, but all other rules are the same as regular chess. Is there a known optimal strategy to win or force a draw?

For example, can one side force the opponent to checkmate (assuming the opponent tries to avoid checkmate)? If not, can one side force a draw by rules like stalemate, threefold repetition, or the fifty-move rule? Or is this as hard to solve as regular chess?

There is likely not a way to force a loss. Selfmates are relatively rare, and one can probably not be forced from the opening position.

The best plan, paradoxically, is likely to try to capture as many of the opponent's pieces (but not pawns) as possible, while keeping your own pieces to be better able to force your opponent. The opponent's pawns are kept because they have very little choice as to where they can move, and can also be easily blocked to avoid the opponent moving them before you want them to. For example, in the following position, the f-pawn is blocked and the king cannot move, so Black has no choice but to advance the g-pawn and will have to checkmate White in two moves:

[FEN "3Q4/8/8/4N3/6p1/7k/5p2/5N1K b - - 0 1"]

  If not, can one side force a draw

Well, if checkmate indeed cannot be forced, then almost by definition a draw could be forced. The game can't go on forever, after all. If nothing else, the players will eventually run out of pawns to move or pieces to capture, and the 50 move rule will come into play.


How many chess clubs are there in the world? I'm interested in the total number of active chess clubs in the world.
I'd also be keen to see any historical trends in this number over the past couple of decades.

I would imagine that the number of chess clubs remain relatively constant. From my small sample size of exposure, I have not witnessed a single chess club die out but have seen a few born. Chess is certainly not decreasing in popularity, so I don't see a reason why there would be a decrease in the number of chess clubs.


What is the longest possible series of consecutive captures? What is this the longest possible series of consecutive captures in a legal position? Here is an example of 25 on the same square, which is not required.

[FEN "q1kr2q1/1qnqnb2/2prp3/q2pK3/2P1P3/1QNQNB2/Q2R2Q1/3R3Q w - - 0 1"]

1. exd5 cxd5 2. cxd5 exd5 3. Bxd5 Qaxd5+ 4. Ncxd5 Rxd5+ 5. Nxd5 Nexd5 6. Qdxd5 Nxd5 7. Qbxd5 Qdxd5+ 8. Rxd5 Qxd5+ 9. Qaxd5 Bxd5 10. Rxd5 Qaxd5+ 11. Qxd5 Qxd5+ 12. Qxd5 Rxd5+ 13. Kxd5

Here's an example of 30 successive captures (White's 3rd to Black's 17th). It is the solution (from White's 3rd onwards) of a massacre proof-game found by Gerd Wilts & Norbert Geissler.

[Title "Gerd Wilts & Norbert Geissler.PDB CD-ROM 1998-Version"]
[StartPly "4"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.d3 d6 2. Bg5 Bg4 3. Bxe7 Bxe2 4. Bxd6 Bxf1 5. Bxc7 Qxd3 6. Bxb8 Qxc2 7. Bxa7 Rxa7 8. Qxc2 Rxa2 9. Qxh7 Rxb2 10. Qxg8 Rxb1 11. Rxb1 Rxh2 12. Rxb7 Rxh1 13. Rxf7 Rxg1 14. Rxg7 Rxg2 15. Qxf8+ Kxf8 16. Kxf1 Rxf2+ 17. Kxf2 Kxg7


Training plan for going from High Class A/Low Expert to National Master... Help? I'm currently hovering around 1970 USCF and am lucky enough that in the next 6 months, I have nearly nothing to do. I'm a returning student, 27 years old, who only needs 1 class to get my degree. I don't need a job currently as my housing is paid for through scholarship.

So, I've decided to take a make a strong leap towards one of my life aspirations, which is to achieve the NM title. I know I'd have to play in a ridiculous amount of tournaments in the next 6 months to get there, but that is okay (I've got the time).

My problem is that I need some structure to really push ahead. If I'm not given any structure or set one for myself, I'll probably play League of Legends and Dragon Age Inquisition and then go... crap, wth was I doing!?

I've tried putting a few plans together, but everything seems a little rough. I know I need work across the board (Opening, Middlegame, Endgame, Calculation, Strategy, etc.) but due to the sheer volume of stuff, I'm a little lost.

I also have nearly unlimited resources. I have Chessbase, have roughly 200 books in CBH format along with another 300 or 400 books as PDFs. If there is a good chess book, I probably have it (which adds to my problem of figuring out what in the world I need to focus on).

I know I can set aside 3 hours a day, every day for certain (weekends included). More than 3 hours and some days I may have to cut it short. Any help in creating a solid training plan of what I should work on each day?

I think you need 3 components to your campaign:

1) Play lots of tournament chess (which you are planning on anyway) preferably against players stronger and much stronger (+200) than you.

2) Analyze your own games and those of your opponents (where the draw is made far enough in advance and you can find their games - over time you will have games that you have played against them).

3) A course of theoretical study.

In your game analysis you are looking to identify when and how you lose games with a view to fixing your problems. Feed them into a chess engine. Stockfish is powerful and free. ChessDB is a good free equivalent of Chessbase in case you have an old or crippled version. At this stage you are aiming to identify lapses of concentration, weak tactical ability / poor chess imagination and "drift" where you aimlessly let your advantage slip away (planlessness or bad plans) or that of your opponent gradually build up (poor fighting spirit).

When you analyze your future opponents' games you are looking to see what they play against your repertoire and look for chances to unsettle them and take the initiative. Prepare what you are going to play against their different likely possibilities and familiarize yourself with the plans appropriate to the position.

In your theoretical studies you are going to want to systematically address 3 or 4 areas.

1) Opening preparation. Decide which openings suit your style and available time for study. Very sharp, current openings will require a lot of work to stay uptodate. You may prefer to limit your required study by choosing openings where you can quickly limit your opponents good replies.

2) Every time you lose an ending or draw one you should have won make a point of going over the theory of that particular ending in something like one of John Nunn's books. Gratuitously study endings you are unfamiliar with. This may not pay off in immediate extra points from getting into these endings (although over time it likely will) but it will improve your general endgame play and in particular your approach to the endgame. A good example of this would be KNBvK.

3) Hone tactics. There are lots of books out there stuffed of tactical problems. Pick one and do a few every day.

4) General chess study. There are several book-series courses out there. The most famous is Dvoretsky's "School of Chess Excellence" series. No offence meant, but I think this is likely to be too advanced for you. I have several of these on my bookshelves but have never managed to read more than a few pages. Maybe when you are going for your IM or GM title ;-). Yusupov has done 3 series of 3 books each - "Build Up Your Chess", "Boost your chess" and "Chess Evolution" which I would recommend you start with. I'm a similar level to you and have actually worked through 2 out of the 9 books and felt I got a lot out of them. You have the time so work through them systematically.

Under the heading of general chess study you should also read "left field" books which will broaden your chess outlook. Example books would be Jonathan Rowson's "Chess for Zebras" and "The Seven Deadly Chess Sins", John Watson's "Secrets of Modern Chess Strategy", Willy Hendriks' "Move First, Think Later"


Polyglot Opening Books vs. Chess Opening Tree Depending on the GUI, I have noticed some use polyglot files for their opening books and others use .ctg(chess opening tree) for their opening books.

Is there an advantage or disadvantage to either or is it based solely on the programmer's preference with no real advantage or disadvantage?

Let's take a look what they are

Polyglot is an open source format. It is free to use, free to distribute, the file format is in public domain. You won't land yourself into any potential legal disputes with Polyglot, as long as you follow the GPL license for the source code.
CTG file format is owned by Chessbase. It's a closed format, and is not open for you to modify. The file format is proprietary. You might land yourself into possible legal disputes if you try to do something stupid. You --might-- need Chessbase's explicit permission if you want to embed it into your own application. Check with your lawyer.

People use Polyglot because:

It's free. The source code is there for everyone.
They don't know how to read the Chessbase opening file format
Open source chess engines don't use CTG. They generally use Polyglot or nothing. I believe it's illegal to embed a proprietary software (you need code to parse the CTG file) into an open source program.

People use CTG because:

It's a more powerful file format than Polyglot. The Polyglot format is really a binary compression of (position, moves, weights). For example, it doesn't have the number of games for each position.
Polyglot is designed for computer chess engines, it sits nicely with engine code, but lacks good support for chess GUI. CTG format is designed for both chess engines and chess GUI.
CTG is a more popular format than Polyglot. Most opening book makers use the Chessbase software.
Polyglot was developed on the UNIX operating system, the source code is much harder to compile on Windows. But most chess book makers use Windows!
There's an experimental CTG loader from scidb, and the related Java implementation somewhere else. However, the implementation in scidb is quite difficult to pull out (not abstracted in software engineering terminology). The Java implementation is useless if your application is not written in Java.

If both CTG and Polyglot were open source and free, there wouldn't be any reason for Polyglot to exist. CTG > Polyglot.


QGD :: should Black fiancheto his King's Bishop? A common line in the orthodox line of the QGD goes something like this:

[FEN ""]
1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Nc3

Here's the part that puzzles me. According to the database in 365chess Black's most common response in 4...Be7 presumably to support the knight in case of 5.Bg5 (which remarkably according to the same database is White's most common move even though after 4...Be7 no tempo is won). Anyhow, why doesn't Black simply play 4...g6 instead so he can conveniently fianchetto the King's bishop in response to 5.Bg5 ? This move does appear in the aforementioned database but way, way low. Why doesn't Black try to occupy the long diagonal with his King's bishop? Is there any strategic reason for Black in QGD for the King's bishop to remain on the a3-f8 diagonal instead?

The main reason why Black tends not to fianchetto in this position is because she has already played ...e6, which in conjunction with playing ...g6 to develop the bishop, unnecessarily weakens the dark squares on the black kingside without gaining anything; instead ...e6 has wasted a tempo that could otherwise be saved, and potentially hindered development of the other bishop. In other words, if Black is about to spend a move playing ...g6 to develop the kingside, it is better to wait on spending a move on the e-pawn.

Now it's true that, having played 1...d5 to start, the move ...e6 serves a purpose of reinforcing the pawn on d5. But this comes at the costs described above. That's why, if Black wants to fianchetto, she instead usually avoids an immediate 1...d5 and opts for things like the Gruenfeld or the King's Indian, moving straight ahead with that scheme of development, and pushing one way or another in the center after other things are clearer.

Consider a mainline King's Indian:

    [FEN ""]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5

Note that Black has here gotten in ...e5 in one fell swoop. And in a Gruenfeld, 1.d4 Nf6 2.c4 g6 3.Nc3 d5, Black has played ...d5 but intends to get away without a reinforcing ...e6 move, instead playing for piece play against White's center.


Canal Attack Stockfish Indication Apparently, Stockfish on depth 22 states that the Canal Attack is the best opening after 1.e4 c5 2.Nf3 d6. Is something wrong with Stockfish?

First of all, stockfish and other chess engines don't have the best reputation of being good at openings, often misevaluating this particular phase of the game. Second of all, Canal attackis perfectly respectable opening. After e4 c5 Nf3 d6, at depth 30, I get
0.53 d4
0.44 Nc3
0.40 Bb5+(canal)
with these three constantly changing positions at different depths. Just so happens that at depth 30, d4 was the most favored, but on 31, my engine switches to Nc3, for example. They are all perfectly reasonable moves, but its not like you can just turn on the engine and expect it give you a verdict about which of the three moves I mentioned are the best.


"Chess is art" who was the first one to use this quote? Who was the very first one to ever use the quote "Chess is art"? Like who was the first one?

I don't think anybody has made such a claim. "Chess is an art" is another matter.

Vaclav Havel (former Czech prime minister) is supposed to have said that when he visited the Carlsbad tournament.

Karpov is supposed to have said "Chess is everything - art, science, and sport."

If anyone should know it would be Marcel Duchamp the artist who gave up art for chess. Although since he put forward a urinal as a work of art I would hope that he would put chess on a more elevated plane.

Perhaps the most quoted saying about the nature of chess is Tarrasch's

  Chess, like love, like music, has the power to make men happy

which does it for me.


How to make an AI chess engine which can play like a human of similar rating? We have lot of sophisticated chess engines, but I always prefer playing with a human online, because they make genuine mistakes / blunders which adds a human touch. Playing with computer at a high level is boring as it is too difficult to crack and at low levels it makes a random blunder which practically a human will never do. Can someone either point me to an existing engine which plays like a human based on your level or recommend me some guidelines as how we can make it using AI ?
Thanks in advance

You can take a look at the Maia Chess project. What they've done is that they've built a customized version of Leela Chess wherein instead of the policy value looking for the best move, it looks for the most likely human move. The github has 9 weight files for lc0 from 1100 to 1900 elo.
It claims to better predict the moves of players compared to Stockfish and Leela Chess. You can also play these bots at Lichess.


Minimax check(mate) detection in my minimax function I have a first few lines looking something like this:

children = board.get_all_possible_moves(board)

if depth = 0 or board.is_check_mate or board.is_draw:
    return None, evaluation(board)

The problem is that it takes time to calculate the children one "extra time" if the depth is 0 and the position is not draw or check mate. However, I want to know if the board state at depth 0 is check mate or draw.

As of now I detect check mate and draw by the following logic:

if not possible_moves:
    if board.is_check:
        board.is_check_mate = True
    else:
        board.is_draw = True

Is there a better way of finding whether a posisiton is check mate or not? Without having to calculate the opponents possible moves first, to save time in the minimax recursive function. Thank you in advance.

Your approach is correct. Stockfish does it as well.

  https://github.com/official-stockfish/Stockfish/blob/master/src/search.cpp

if (rootMoves.empty())
{
  rootMoves.emplace_back(MOVE_NONE);
  sync_cout << "info depth 0 score "
            << UCI::value(rootPos.checkers() ? -VALUE_MATE : VALUE_DRAW)
            << sync_endl;
 }

There shouldn't be much penalty in performance, because:

You will always need to generate candidate moves anyway
Your code should maintain a bitboard (or other data structure) for the pieces checking the king. You will always need this information in your evaluation.

Consequently, what you're doing is just checking information that you already have.


Why and when should one make a zwischenzug (in-between move)? I know enough German to know that the term "zwischenzug " means "in-between move." Another translation I've seen is an "interpolative" move. Why make such a move?
An example is when a rook wants to go to the seventh rank. First, it goes to the eighth rank, let's say with check, and when the opponent replies, the rook goes back to the seventh. What might be the advantage of using such a "roundabout" route to get to the seventh rank?
In GO (where I'm higher rated than in chess), it might be called a forcing move. You make a "throwaway" move that forces a particular response, and then you make your main move, and the two together are stronger than making the main move alone. How might this work in chess?

That's really an enormously broad question. The answer is "because it's a good move, sometimes." :-)

Let's say one player expects the game to go "I take here, then he takes there, I take there, he takes there, I take back the rook... and I end up a pawn up."

What happens is "I take here, he takes there, I take there, he moves the rook with check, I have to move my king, he takes there, I can't take back the rook... and I end up a rook down."

That's the sort of situation where a zwischenzug helps. When what at first looks like a forced sequence of moves can actually have an extra move added to the middle of it that makes the end result better for the side doing it.

Turning this into some actual position with a diagram and such is left as an exercise for the reader.


How would the evaluation of the engine suggested endgame in the Anand vs Carlsen game be determined? In round 7 of the Tata Steel Masters 2020, there was a game between Anand and Carlsen. Anand had the upper hand out of the opening but they drew on move 54. Instead, Anand missed 54.Rb4! Nxc7 55. Rc4 leading to this forced position. Stockfish 10 at depth 37 evaluates at +1.47. If this were the case what would be the technique to win such an ending?

 [Event "Tata Steel Masters"]
 [Site "Wijk aan Zee"]
 [Date "2020.01.18"]
 [Round "7"]
 [White "Anand, Viswanathan"]
 [Black "Carlsen, Magnus"]
 [Result "1/2-1/2"]
 [ECO "B31"]
 [WhiteElo "2758"]
 [BlackElo "2872"]
 [Annotator "DF"]
 [PlyCount "114"]
 [EventDate "2020.??.??"]
 [FEN ""]

 1. e4 c5 2. Nf3 Nc6 3. Bb5 g6 4. O-O Bg7 5. c3 Nf6 6. Re1 O-O 7. d4 a6 8. Bd3 d5 9. e5 Ne8 10. dxc5 Bg4 11. Be2 Nc7 12. Nbd2 a5 13. h3 Bc8 14. Bd3 Ne6 15. Nb3 a4 16. Nbd4 Nxc5 17. Bc2 Qa5 18. Bd2 Rd8 19. Qc1 Ne6 20. b4 Qc7 21. Nxc6 bxc6 22. Be3 c5 23. bxc5 Nxc5 24. Qa3 Ne6 25. Rab1 d4 26. Nxd4 Bxe5 27. Nb5 Qc6 28. Rb4 Bb7 29. Be4 Qd7 30. Bxb7 Qxb7 31. Rxa4 Bf4 32. Rxa8 Rxa8 33. Qb3 Bxe3 34. Rxe3 Nf4 35. Rf3 Qe4 36. Kh2 Nd5 37. c4 Qe5+ 38. g3 Nf6 39. a3 Ne4 40. Qc2 Ng5 41. Re3 Qc5 42. h4 Ne6 43. Qe2 Rc8 44. Rc3 h5 45. Kg2 Kf8 46. Qe4 Kg8 47.  d5 Qb6 48. a4 Qa6 49. c5 Qxa4 50. c6 Rd8 51. Qc4 Qxc4 52. Rxc4 Rb8 53. c7 Rc8 54. Rb4 (54. Rc1 {Was played and draw agreed.}) 54... Nxc7 55. Rc4 Nxb5 56. Rxc8+ Kg7 57. Kf3 Nd6 $16

First, despite the big eval, it is still probably equal in the long run with best play. In the games below, the weaker side often weakened the position, making easier for the stronger side to win. When in doubt, it is probably not a good idea to move pawns while defending.

It is of note that Anand, and I am sure this is not accidental here, has the optimal kingside pawn setup with f7-g6-h5. Remember that setup as it makes it hard for white to get a passed pawn, or otherwise attack the black pawns. That black also has an e-pawn makes it better here. I will give a couple of games below without the e-pawn that white managed to win just to show some possible ideas.

Again, it is still likely drawn, but if white were to be able to do anything, it is clear that e7 and f7 are the black soft spots, so any successful plan would involve the rook attacking them, most likely with a king walk to the eight rank somehow. This type of king walk ins not uncommon in some endgames with all the pawns on one side. That said, it is definitely worth playing on here.

I could not find any games with the pawn on e7 (I did find some with the pawn on e3, and colors reversed after, and added the wins below), but I did find a three games with the pawn on e6 that were all drawn, with one by famous players (the other two are not worth showing as one was between lower-rated players, and the other between low 2400s, but in blitz). In the first, you can see Najdorf successfully defend by tying down white to f2 and then advancing his central pawns. Despite the draw, I am a bit skeptical of how black played based on some of the games below.

 [Event "Venice"]
 [Site "Venice"]
 [Date "1948.??.??"]
 [Round "?"]
 [White "Euwe, Max"]
 [Black "Najdorf, Miguel"]
 [Result "1/2-1/2"]
 [ECO "D72"]
 [PlyCount "102"]
 [EventDate "1948.??.??"]
 [EventType "tourn"]
 [EventRounds "13"]
 [EventCountry "ITA"]
 [FEN ""]

 1. d4 Nf6 2. c4 g6 3. g3 Bg7 4. Bg2 d5 5. cxd5 Nxd5 6. e4 Nb6 7. Ne2 Nc6 8. d5 Nb8 9. Nbc3 c6 10. O-O cxd5 11. exd5 O-O 12. Qb3 N8d7 13. a4 Ne5 14. a5 Nbd7 15. Be3 Ng4 16. Bd4 Bxd4 17. Nxd4 Ngf6 18. a6 Nc5 19. axb7 Bxb7 20. Qb5 Qb6 21. Rfe1 Rfe8 22. b4 Na6 23. Nc6 Kf8 24. Qc4 Nc7 25. Na4 Qb5 26. Qxb5 Nxb5 27. Nc5 Bxc6 28. dxc6 e6 29. Nd7+ Ke7 30. Nxf6 Kxf6 31. c7 Nxc7 32. Bxa8 Rxa8 33. Ra5 Nd5 34. Rb1 Rb8 35. Rxa7 Rxb4 36. Rxb4 Nxb4 37. h4 h5 38. Kg2 Nc6 39. Rd7 Ne5 40. Rc7 Ng4 41. Kf3 Nh6 42. Kf4 Nf5 43. Ke4 Nh6 44. Rc3 Ng4 45. Rf3+ Ke7 46. Kd4 f5 47. Kc3 e5 48. Kd2 e4 49. Ra3 Nxf2 50. Ra6 Kf7 51. Ke3 Nd3 1/2-1/2

Here are a couple of games without the extra e-pawn just to show some similar games that white won. The first is close to how I imagined trying to win, and the second shows black not defending too well.

 [Event "Warsaw AIG Life rapid 9th"]
 [Site "Warsaw"]
 [Date "2009.12.20"]
 [Round "11"]
 [White "Sergeev, Vladimir"]
 [Black "Lind, Jan Olov"]
 [Result "1-0"]
 [ECO "A48"]
 [WhiteElo "2428"]
 [BlackElo "2209"]
 [PlyCount "129"]
 [EventDate "2009.12.19"]
 [EventType "swiss (rapid)"]
 [EventRounds "13"]
 [EventCountry "POL"]
 [FEN ""]

 1. d4 Nf6 2. Nf3 g6 3. Bg5 Bg7 4. Nbd2 c5 5. e3 b6 6. c3 O-O 7. h3 Bb7 8. Bd3 d6 9. O-O Nbd7 10. a4 a6 11. Qe2 Qc7 12. e4 e5 13. dxe5 dxe5 14. Rfd1 Rfe8 15. Bc2 Nf8 16. Nc4 Re6 17. Bxf6 Bxf6 18. Bb3 Rd8 19. Rxd8 Qxd8 20. Rd1 Qc7 21. Ne3 Rd6 22. Bd5 Ne6 23. Qc4 h5 24. h4 Kg7 25. g3 Qd7 26. Ra1 Bxd5 27. Nxd5 b5 28. axb5 axb5 29. Qe2 c4 30. Qe3 Rxd5 31. exd5 Qxd5 32. Re1 Nc5 33. Nxe5 Na4 34. Re2 Bxe5 35. Qxe5+ Qxe5 36. Rxe5 Nxb2 37. Rxb5 Nd1 38. Rc5 Nxc3 39. Rxc4 Nd5 40. Rc6 Nf6 41. Kg2 Ng4 42. Ra6 Ne5 43. Kf1 Ng4 44. Ke2 Ne5 45. f3 Nd7 46. Ke3 Nf6 47. Kd4 Ng8 48. Ke5 Nh6 49. Kf4 Ng8 50. Ra7 Nf6 51. Ra5 Ng8 52. g4 hxg4 53. fxg4 Nf6 54. g5 Nd7 55. Ke4 Nf8 56. Ra6 Nd7 57. Kd5 Nf8 58. Rd6 Nh7 59. Kc6 Nf8 60. Kc7 Nh7 61. Kd8 Kf8 62. Rb6 f6 63. Rb7 Kg8 64. Rxh7 fxg5 65. Rh6 1-0

And the second:

 [Event "Belgrade Trako"]
 [Site "Belgrade"]
 [Date "1995.??.??"]
 [Round "5"]
 [White "Ostojic, Nikola"]
 [Black "Nestorovic, Dejan"]
 [Result "1-0"]
 [ECO "D85"]
 [WhiteElo "2465"]
 [BlackElo "2415"]
 [PlyCount "105"]
 [EventDate "1995.03.??"]
 [EventType "tourn"]
 [EventRounds "13"]
 [EventCountry "YUG"]
 [EventCategory "9"]
 [FEN ""]

 1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Bb5+ c6 8. Ba4 O-O 9. Ne2 c5 10. O-O Nc6 11. Be3 Qc7 12. Qc2 Na5 13. Qc1 Bd7 14. Bxd7 Qxd7 15. Bh6 cxd4 16. Bxg7 Kxg7 17. cxd4 Rac8 18. Qe3 b6 19. Rad1 Rc2 20. d5 Rxa2 21. Nd4 Kg8 22. Rd3 Nc4 23. Qc1 Rc8 24. Nc6 Rxc6 25. Qb1 Rd2 26. Rxd2 Nxd2 27. dxc6 Qxc6 28. Rc1 Qb7 29. Qd3 Nxe4 30. Qd8+ Kg7 31. Rc7 Qa6 32. Qd4+ Nf6 33. Rxe7 h5 34. h3 Qa5 35. Qc4 Qd5 36. Qxd5 Nxd5 37. Rxa7 Kf6 38. Kf1 Ke6 39. h4 Kf6 40. g3 Ke6 41. Ke2 Nf6 42. Kd3 Ng4 43. Ra2 Kf5 44. Rb2 Ne5+ 45. Kd4 Nd7 46. Kd5 Nf6+ 47. Kd6 Ne4+ 48. Ke7 g5 49. Kxf7 gxh4 50. gxh4 Nc5 51. Rxb6 Nd3 52. Rb3 Ne5+ 53. Kg7 1-0

I found two more wins but with colors reversed and with the e-pawn. The first win is by the venerable Yermo, who is a great endgame expert. In this game, you see Yermo try to get a passer with f6, and g5, but when white does not trade, he grabs space instead. Then you see the king walk again hitting the soft spots. This is probably the game you should imitate. If there were a "textbook example", I would probably use this one.

 [Event "Western Pacific op 3rd"]
 [Site "Burbank"]
 [Date "2005.03.26"]
 [Round "3"]
 [White "Kretchetov, Alexandre"]
 [Black "Yermolinsky, Alex"]
 [Result "0-1"]
 [ECO "E11"]
 [WhiteElo "2326"]
 [BlackElo "2570"]
 [PlyCount "146"]
 [EventDate "2005.03.25"]
 [EventType "swiss"]
 [EventRounds "5"]
 [EventCountry "USA"]
 [FEN ""]

 1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+ 4. Bd2 c5 5. Bxb4 cxb4 6. g3 O-O 7. Bg2 d6 8. O-O Re8 9. a3 bxa3 10. Rxa3 Nc6 11. Nc3 a5 12. Nb5 Na7 13. Nxa7 Rxa7 14. b4  b6 15. Qc2 Qc7 16. Rfa1 Bb7 17. Nd2 Bxg2 18. Kxg2 e5 19. dxe5 Rxe5 20. Nf3 Re4 21. bxa5 Rxa5 22. Rxa5 bxa5 23. Qd2 Qxc4 24. e3 a4 25. Qxd6 Re8 26. Nd4 h5 27. h3 Ra8 28. Ra3 Ne4 29. Qe5 Nd2 30. Qb5 Qxb5 31. Nxb5 Nc4 32. Rc3 a3 33. Rxc4 a2 34. Rc1 a1=Q 35. Rxa1 Rxa1 36. h4 g6 37. Nd4 Kg7 38. Nf3 Ra2 39. Nd4 Kf6 40. Kf3 Rb2 41. Ne2 Ke5 42. Nf4 Rd2 43. Ne2 Rd6 44. Nf4 Rf6 45. Kg2 Ke4 46. Nh3 Kd3 47. Ng1 Ra6 48. Nf3 f6 49. Kf1 Ra5 50. Kg2 g5 51. Kf1 g4 52. Nd4 Ra6 53. Nb5 Rb6 54. Nd4 Kd2 55. Kg1 Rb1+ 56. Kg2 Rd1 57. Ne6 Ke1 58. Nf4 Rd2 59. Kg1 f5 60. Nxh5 Rxf2 61. Nf4 Ra2 62. h5 Kd2 63. Kf2 Kc3+ 64. Kg1 Kc4 65. Ng6 Kd5 66. Nf4+ Ke4 67. h6 Ra6 68. h7 Rh6 69. Ne6 Kxe3 70. Ng5 f4 71. gxf4 Kxf4 72. Ne6+ Kg3 73. Ng5 Kh4 0-1

And IM Tania Sachdev, who was not an IM at the time, being beaten by a fellow IM.

 [Event "Olomouc Proclient Cup"]
 [Site "Olomouc"]
 [Date "2004.07.08"]
 [Round "6"]
 [White "Sachdev, Tania"]
 [Black "Gavrilov, Alexei V"]
 [Result "0-1"]
 [ECO "E18"]
 [WhiteElo "2240"]
 [BlackElo "2441"]
 [PlyCount "118"]
 [EventDate "2004.07.04"]
 [EventType "tourn"]
 [EventRounds "11"]
 [EventCountry "CZE"]
 [EventCategory "2"]
 [FEN ""]

 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3 Bb7 5. Bg2 Be7 6. O-O O-O 7. Nc3 Na6 8. Bf4 d6 9. Rc1 Re8 10. a3 c5 11. dxc5 bxc5 12. Qc2 Qb6 13. Rfd1 d5 14. cxd5 exd5 15. Nh4 d4 16. Na4 Qb5 17. Bxb7 Qxb7 18. Nf5 Nd5 19. Bd6 Bg5 20. Bxc5 Bxc1 21. Rxc1 Nxc5 22. Nxc5 Qb6 23. Nxd4 a5 24. Qb3 Qxb3 25. Ncxb3 Nb6 26. Rc5 Na4 27. Rxa5 Nxb2 28. Rxa8 Rxa8 29. Nb5 Nc4 30. Kg2 Nxa3 31. Nxa3 Rxa3 32. Nd4 g6 33. e3 Kg7 34. h4 Kf6 35. Nf3 h5 36. Ng5 Ra7 37. Kf3 Ke5 38. Nh3 Ra2 39. Nf4 Kf5 40. Nd3 Ra3 41. e4+ Ke6 42. Ke3 f6 43. f4 f5 44. exf5+ gxf5 45. Kd4 Kd6 46. Kc4 Ra1 47. Ne5 Rg1 48. Nf3 Rxg3 49. Nd4 Rg4 50. Nxf5+ Ke6 51. Nd4+ Kf6 52. Kd3 Rxf4 53. Ke3 Rxh4 54. Nf3 Ra4 55. Kf2 Kf5 56. Kg3 Ra3 57. Kg2 Kf4 58. Ng1 Kg4 59. Ne2 Ra2 0-1


Best websites for correspondence chess? I've had some bad experiences with Chess.com recently. What are some good alternative websites for correspondence chess? I'm particularly looking for:

No time limit
Email notifications when it is your turn
Ideally, you should be able to make moves by replying to notification emails (with a simple expression like e2e4)

Thoughts?

Apart from chess.com, here are a few others:

http://www.queenalice.com
http://www.gameknot.com
http://www.redhotpawn.com
http://www.chessos.com
http://www.chess-mail.com

There are many out there...


What is the theoretical consensus on the Roscher Gambit? Edit: My mind played a trick on me after the fact. As Akavall notes in a comment, the Chadaev-Carlsen blitz game that I mention below actually proceeded 1. e4 g6 2. d4 Nf6 3. Nf3, a different gambit than the one my question asks about. So please ignore the references to Chadaev-Carlsen in reference to the Roscher Gambit here. (Incidentally, this means that Carlsen didn't buck the trend of highly-rated players avoiding 3. ... Nxe4 in the Roscher Gambit; see below.)

The Roscher Gambit goes as follows:
[FEN ""]

1. e4 d6 2. d4 Nf6 3. Nf3

I just saw Nikolai Chadaev convincingly defeat Magnus Carlsen at the World Blitz Championship using this line (where Carlsen accepted the gambit with 3. ... Nxe4). I realized I've basically never seen this gambit, and that I know nothing about it. (I even had to look up a name for it to ask this question.)
It is very seldom played, and especially so among highly-rated players: my database of 5.2M games contains a mere 99 games reaching the position after 3. Nf3, with the average White (respectively, Black) rating in the games being 1953 (1976). But there are 7 games in which 2400+ players tried the gambit as White against equally strong competition (and 2 games with 2500+ players). The most popular response over all games is indeed the obvious 3. ... Nxe4, being chosen in 46 of the 99 games. (Second most popular is continuing in Pirc Defense fashion with 3. ... g6; these two moves account for almost all the games, 83 of 99.)
All of that is about what I would expect. But, interestingly, in the games I have in this line with the highest-rated players, Black consistently avoids 3. ... Nxe4, preferring the 3. ... g6 Pirc approach, or instead aiming for the Philidor with 3. ... e5 (or 3. ... Nbd7 followed by 4. ... e5), Czech Defense with 3. ... c6, or even the Nimzowitsch Defense with 3. ... Nc6. The highest rated player I find playing 3. ... Nxe4 has Elo 2245 (until this Carlsen blitz game of course).
The sample size here is quite small, and maybe the highly-rated players have avoided 3. ... Nxe4 just because they are worried about stepping in to a well-prepared trap, instead preferring to head for more familiar ground. Nevertheless, the fact that the strongest players consistently avoid accepting the gambit - except for Carlsen, who got stomped, though it's just a blitz game - has made me curious:

What is the the theoretical status of the Roscher Gambit? Or is it too seldom played to even have a theoretical status?
And if it's the case that 3. ... Nxe4 isn't simply good for Black, then why doesn't the Roscher appear more often, or at least have the same popularity among amateurs as something like, say, the Blackmar-Diemer Gambit?

I had no luck finding any prose account of the gambit by a strong player, and would appreciate any pointers to such.

I've taken a look at this gambit before as I play it frequently in blitz games, and I don't have very much faith in it for white. (Usually my games are from a different move order with c4 included for white).

The biggest problem with the gambit is that it can be quite simply declined with 3... g6 and what has white really accomplished?  There's nothing better than transposing into either a Pirc with 4. Nc3 or a King's Indian Defense with 4. c4 (incidentally allowing black another chance to accept the gambit in an even better way).

Obviously declining the gambit isn't the critical path, however.  Black's most challenging move is 3... Nxe4 when white more or less must play 4. Bd3.  Any other move is inconsistent although there are a few move order tricks like 4. Bb5+ which I will return to later.

Now we see the biggest issue with the gambit - white doesn't get a "real" lead in development or force any concessions in the black position.  Black plays 4... Nf6 (entire line so far 1. e4 d6 2. Nf3 Nf6 3. d4 Nxe4 4. Bd3 Nf6) and now both players can finish development naturally.  Black will play g6, Bg7, O-O and Nc6 with a perfectly acceptable Dragon formation.  On the other hand, white cannot mount a standard kingside attack with g4 and h4 because the knight on f3 will allow the black bishop to come unmolested to g4.

White doesn't have any targets to attack in the black position and will be completely unable to stop black from castling.  These are the two goals of a gambit - force a concession and attack with the lead in development.  While the pawn sac is probably not bad in and of itself because white keeps a normal edge as in so many Pirc and KID positions along with the open e file for future use, after black castles kingside, the e pawn is quite immune from capture due to moves like Re8, Kf8, and Nc6.

So at last we return to white's tricky attempt 4. Bb5+.  If black plays 4... c6 now white has something since the knight is deprived of the c6 square.  However, black simply plays 4... Bd7 and there are no problems because the d7 square is not reserved for other pieces in the Dragon formation.  Both sides "waste" a tempo so nothing is gainer or lost.
In fact, even after 4... c6, black can still claim barely equality, although this is a real concession in the position (Nb8 cannot develop naturally).  If I were to play white, I think that 4. Bb5+ is the best attempt simply because many players will play the natural looking 4... c6 to drive the bishop back.

[FEN ""]
[White "Roscher Gambit"]
[Black "Analysis"]

1. e4 d6 2. d4 Nf6 3. Nf3 Nxe4 (3... g6!? {White has gained nothing over the usual Pirc move order}) 4. Bd3 (4. Bb5+!? c6?! {Black's knight is deprived of the c6 square} (4... Bd7!)) Nf6 {Both players will continue to develop normally and black doesn't have any weaknesses}


Analyzing using Chess Engines - Giuoco Piano/Steinitz Variation [FEN ""]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. c3 Nf6 5. d4 exd4 6. cxd4 Bb4+ 7. Nc3 Nxe4 8. O-O  Bxc3 9. bxc3 d5 10. Ba3 dxc4 11. Re1 Be6 12. Rxe4 Qd5 13. Re3 O-O-O 14. Ne5 Nxe5 15. Rxe5 Qxe5 16. dxe5 Rxd1 17. Rxd1 Bf5

Black's position is better.

a) From move 1 to 12 are Theoretical Variations which I have understood clearly and played in the club level match.

b) I played 13. Re3 with the logic of protecting the f3 Knight by the pin of ...Bg4. Then my Queen can move freely to other squares not fearing the pin. Also it helps in doubling the Rooks or Rook & Queen on e file. When Analyzing the game with the engine Deep Fritz 12 the move 13. Re3 played by me matched with the Engine's move. 13... 0-0-0 played by my opponent is also matched with the Engine's move.

c) I played 14. Ne5 with the idea that if 14...Nxe5, then White will play 15. Rxe5 attacking the Queen. But I did not see the move 15... Qxe5 which gives Black some advantage with exchange of pieces since he is already a Pawn up.

d) Hence the recommended move by Deep Fritz 12 is 14. Qa4 instead of 14. Ne5.

Questions.

1) Can I agree with the Recommended Line of Deep Fritz 12?

2) Since there are many Engines now like Deep Fritz 12, Fritz 8, Fritz 16, Online Fritz, Chess Master Grand Master Edition etc. and still higher versions coming to market, which engine I can believe? How we can analyze our game using which best engine? The different engines may give different Recommendations of moves. In such cases, how a Club Player who regularly analyses and studies his game after the match can study the variation? He gets CONFUSED. How can he get the best variation out of many variations suggested by different engines? On Which Engine he can have faith? Is there a No. 1 Best Universal Engine (whom we can believe throughout our life irrespective of new higher versions of Engines coming to market) for it's Recommended moves and we can employ these moves in our further games in our tournaments? Requesting experts to please answer me and guide so that I can follow it throughout my life.

3) By the way, what may be the logic behind 14. Qa4?

Chess Stack Exchange has helped me a lot. Thanks to all experts from this best website in the world.

1) Can I agree with the Recommended Line of Deep Fritz 12?

Re3 is a perfectly reasonable move, and Stockfish 9 also agree's with it. This isn't to say that there aren't other moves to consider such as Qe2 or even the more passive Re1. Also bare in mind that some engine recommendations don't really follow our human style and as such are sometimes hard to grasp and follow through.

  2) Since there are many Engines now like Deep Fritz 12, Fritz 8, Fritz 16, Online Fritz, Chess Master Grand Master Edition etc. and still higher versions coming to market, which engine I can believe?

In truth all of them are similar, and to a club level player it really doesn't matter which engine you chose among the ones you mentioned. If those engines are giving you different moves for the same position its because all the moves are equally strong. Note that engines have versions because they are always being updated and as such it's import to have them updated as much as possible.

Personally i feel Stockfish is one of the best options out there because not only is it one of the highest rated engines, but it is also open source.

Now you shouldn't follow a move recommendation if you don't understand the logic behind a move, otherwise you just memorizing moves and not really improving. This is also why it is important to know the core chess concepts, such as piece development, center control, pawn structure, etc...

  3) By the way, what may be the logic behind 14. Qa4?

There are many ideias behind Qa4:

Avoid trading - It is the exact opposite of what you did with Ne5 allowing Nxe5 and the consecutive simplification to rook and bishop endgame being a pawn down. Its important to say that if the rooks are traded off then it will mostly result in a draw despite being a pawn down because its a opposite colored bishop endgame.
Connecting/Doubling rooks - Moving the queen off the first rank allows both rooks to connect later on with Ree1 or even doubling on the E file with Rae1
Queenside attack - By playing Qa4 you now pressure a7 tying down the knight to its defense. If unanswered then Ne5 will be a threat that removes the defender of a7 and allows you penetrate further with Qxa7. In this case even though you trade a knight down it gives you a lot of attacking options and more importantly the queens aren't traded. Also the B file is now open to a possible Rb1 that pressures the enemy king.

All these points make Qa4 better than Ne5 because they give you a lot more counter-play and fighting chances.


Why don't masters prevent the pin after Bg4 in the modern Italian game? In the Italian game, according to the Lichess masters database, the play usually starts similarly to
[FEN ""]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. c3 Nf6 5. d3 d6 6. O-O O-O 7. Bb3

However, this completely ignores the threat of Bg4, that can be played by black after 5... d6. This pin is somewhat nasty, since it can't be broken by retreating the light-squared bishop to e2 and breaking the pin by h3 followed by g4 weakens the kingside considerably.
I also remember some chess video recommending beginners to play h3 as soon as black plays d6 in the Italian game. Interestingly, Stockfish evaluates this position after playing 7... Bg4 as roughly +0.5, so 7... Bg4 is an inaccuracy. Actually, the engine also claims that after 7... a6 8. Bg5 an analogous pin from white also leads from white's slight advantage to an equality.
Why do masters (and higher-rated players) ignore the threat of Bg4?

You're referring to ...Bc8-g4 as a threat. The only threat it makes is ...Bg4xf3, losing time and the bishop pair.
While White has d4 under wraps with a pawn at c3, theere's no ...Nc6-d4 coming to pressure the pinned knight. The f6-knight has to move to a lesser square to prepare ...Qd8-f6, which is nothing because Nb1-d2 is right at hand to prevent a fracture of White's king position.
A bishop at g4 is a target for this maneuver: Nb1-d2-f1-e3 or Nb1-d2-f1-g3 plus h2-h3 when the bishop can't maintain the pin by ...Bg4-h5. White also has the option of h2-h3 plus g2-g4 (if ...Bh5) then one of those knight maneuvers aims for f5 at the end. See, you're talking about h3 plus g4 like it's a bad thing but while the center control and development are equal, it's not so risky to create those holes in the king position, and if there's nothing going on the center, then that expansion (or a4, b4, a5, etc. on the other wing) is one of the only ways to generate heat.
This is not a position for inexpert players to be concerned with. It's very quiet, which is OK for masters, because they know how to fend off an opponent who stirs it up too soon, and because they know how to open the quiet position when it's the right time. Average players and students should be studying games in which the tactics arise early, because it's recognizing those tactics that eventually gets them to where they're genuinely able to play these humdrum Giuoco Pianos.


Will there be any anti-cheating measures that affect the broadcast in the Candidates tournament? In the current Women World Championship the games are transmitted with a delay to avoid cheating. Searching if something similar will happen for the Candidates tournament I could just found the information that the games will be only be available in the official webpage.

Is it going to be any delay or any other anti-cheating measure that affects the broadcasting of the games applied in the Candidates?

Is it going to be any delay or any other anti-cheating measure that
  affects the broadcasting of the games applied in the Candidates?

It is mostly Agon protecting their commercial rights to the event.

They forbid rebroadcasting and require users / viewers to login and click agreement to a complicated piece of lawyer-speak which is unintelligible to normal people.

Being cynical I expect any delay for other organizations covering the event will come from one of their members subscribing and then playing the moves on a chessboard in front of him so somebody else can broadcast them.

There is no copyright on chess moves or games, only on commentary.


Do the rules of chess state that a Bishop+King can be sufficient mating material? A famous recent example of this ending happened last year between Carlsen and Firouzja.

Here, Firouzja time ran out, so Carlsen won

[Title "Alireza Firouzja-Magnus Carlsen, World Blitz Championship, Moscow Russia, 12/30/2019"]
[FEN ""]
[startply "132"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 d6 5. O-O Bd7 6. c3 g6 7. d4 Bg7 8. h3 Nf6 9. Bc2 O-O 10. Re1 Re8 11. Nbd2 Qe7 12. Nf1 Qf8 13. Ng3 Bh6 14. Ng5 Nd8 15. Bb3 Ne6 16. h4 Rad8 17. Be3 Bg7 18. h5 Bh6 19. Qc1 Ng4 20. Nxe6 fxe6 21. Rf1 Nxe3 22. fxe3 Qe7 23. hxg6 hxg6 24. Qd2 exd4 25. cxd4 Kg7 26. Rf3 Rf8 27. Raf1 Rxf3 28. Rxf3 Rf8 29. Qc3 c6 30. Nf1 e5 31. Rxf8 Kxf8 32. Qc4 Qf6 33. dxe5 dxe5 34. Qb4+ c5 35. Qxb7 Bb5 36. Qc8+ Ke7 37. Qxc5+ Qd6 38. Qxd6+ Kxd6 39. Bf7 Bxf1 40. Kxf1 g5 41. Ke2 Bf8 42. Kf3 Ke7 43. Bc4 a5 44. Ke2 Kd6 45. Bd5 Be7 46. Kf3 Bd8 47. Kg4 Be7 48. Kf5 Bd8 49. g4 Be7 50. a3 Bd8 51. b4 axb4 52. axb4 Be7 53. b5 Bd8 54. Kg6 Kc5 55. Kf5 Kxb5 56. Kxe5 Kc5 57. Ke6 Ba5 58. e5 Bd2 59. e4 Bc3 60. Kf5 Kb6 61. e6 Kc7 62. Kg6 Kd8 63. Kxg5 Ke7 64. Kh5 Bd2 65. g5 Bf4 66. Kg4 Bd2

In that tournament, the arbiter ruled that Carlsen wins since the he (technically) had sufficient mating material (a King+Bishop, and  Firouzja had >=1 piece in addition to their King). There is a concise explanation here (from 10m 42s)

Question

Does this rule stand in majorchess tournaments? Or is there some special rule to cover this situation and override the idea that King + Bishop is sufficient for checkmate if the opponent has at least one piece in addition to their king?

Note

Some (possibly in/correct) answers here state that the rules of chess deem such a situation to not have sufficient mating material. I am not sure how reliable they are.

First, Carlsen, despite having only the Bishop, WON that game. So it is not about mating material, but about ANY possible mating position, and there was one here.

The rule at hand is this:

  Paragraph 6.9 of the FIDE Laws of Chess state:

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

There were positions that white could be mated, even though it required total cooperation, and there is no way that Firouzja would have allowed it. That was irrelevant, so it was a loss.

Also see this related question.

Here are the USCF rules.

14D. Insufficient material to continue.

The game is drawn when one of the following endings exists as of the most recently determined legal move, in which the possibility of a win is excluded for either side.

14D1. King vs. king.

14D2. King vs. king with bishop or knight.

14D3. King and bishop vs. king and bishop, with both bishops on diagonals of the same color.

14D4. No legal moves leading to checkmate by opponent. There are no legal moves that could lead to the player being checkmated by the opponent

So, even these rules are quite specific as to the material for an automatic draw.


Longest forced win with just a Knight or Bishop A single knight or bishop usually isn't enough to force checkmate. However, I know there are certain positions where the defending side has his king in front of a rook pawn where a win can be forced.

So I have two questions related to this:

What is the longest forced win where the winning side has only a knight or bishop?
Are there any nontrivial (i.e., not mate in 1) forced wins that don't involve the losing side having his king trapped in front of a rook pawn?

According to this website, the longest checkmate for K+B vs. K+P is a simple mate in one, e.g.

[FEN "8/8/8/8/8/8/p7/k1K1B3 w - - 0 1"]

The K+N vs. K+P case is slightly more interesting, the following position is mate in seven:

[FEN "8/8/8/8/p7/8/N7/k1K5 w - - 0 1"]

1. Nb4 a3 2. Nc2+ Ka2 3. Nd4 Ka1 4. Kc2 Ka2 5. Ne2 Ka1 6. Nc1 a2 7. Nb3#

You can play these endgames with online tablebases, e.g. this one from Shredder.


Ruy Lopez, Exchange Variation [FEN ""]
1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bxc6 dxc6 5. Nc3 f6

Theory recommends 5. ... f6. Why? What is the specific reason behind this move? How this move helps Black? Other than 5. ... f6, are there any other good moves available for Black?

White is threatening to take the pawn on e5. It couldn't take it with 5.Nxe5 because, since the pawn on d4 is undefended, Black can immediately get it back with ...Qd4 6.Nf3 Qxe4+. Or Black could also consider ...Qg5 followed by ...Qxg2. With 5.Nc3, the e4 pawn is defended, making the threat of taking on e5 more serious. If you look at games between highly rated players, 5...f6 is indeed the most popular move, but there are other alternatives that are also fairly frequent, such as ...Qd6 and ...Bd6. I'm pasting below the table from the lichess opening book. If you look at all the popular moves (say those with more than 10 games), they all defend the pawn one way or another (in the case of 5...Bc5 it is a bit tactical).

That said, I don't know why defending with ...f6 is the most popular. It is simple and solid, I suppose (maybe they prefer to defend a pawn with a pawn to give more freedom to the pieces?). If you go by results, protecting the pawn with the queen or bishop (the second and third choices above) are also fairly common moves and actually have a higher frequency of wins for Black (but also for White!).


How is Alpha Zero "more human"? I have a possibly naive question about AlphaZero. I have seen it described as playing in a "more human" style than other computers, but whatever it does, it gains about 100 ELO points by doing it. Kasparov, and many others, have claimed that a strong human in collaboration with a computer will beat a strong computer (perhaps by about 100 ELO??). So an obvious question is, how would AlphaZero compare with a "centaur" combination?

Having only looked at a few games, what I notice is that most computers play wide open games that maximize their own mobility, but AlphaZero seems very concerned to limit the opponents mobility. In a human player I would describe this as a matter of style, not more or less human.

Page 5 in the paper has your answer:

  ... AlphaZero compensates for the lower number of evaluations by using its deep neural network to costs much more selectively on the most promising variations - arguably a more "human-like" approach to chess ...

"selectively" is the key word. What does that mean? Let's use this following position for our example:

  https://chess24.com/en/read/news/london-classic-5-caruana-shows-how-it-s-done

This is a recent game won by Caruana in 2017 London Chess Classic. The White bishop is under attacked, and you know you have to move it. But where?

Possibilities (not losing a piece):

Bh4
Be3
Bd2
Bc1

What was Caruana thinking?

  I felt like I would lose at some point, but when I saw, 25.Bc1 I suddenly
  started to get a bit more optimistic about my chances. I realised my
  position is bad, but at least I had a plan and that was really all I needed
  for some confidence in this position. When I saw this b3, c4 the position is
  double edged and I have some chances.

This is human thinking, and a "human move". Caruana hadn't considered Bh4, Be3 and Bd2 because they "looked" bad. He had been focusing only and only on the Bc1 move.

Humans play chess very selectively, we discard unreasonable moves because we don't have time to examine all possibilities equally.

We discard Bh4 because it release the tension on the h6 pawn
We discard Be3 because it blocks the two white rooks on the third rank
We discard Bd2 because it blocks the White queen to the king side

That's what AlphaZero trying to claim in the paper. They claim their algorithm, although slower than Stockfish, is able to selectively pick better moves than Stockfish in the search. While Stockfish is faster, it wastes time on bad moves. AlphaZero is slower, but it's more precise (like what Caruana was doing).

For example, AlphaZero might spent 80% resources on Bc1, and 20% on all other bishop moves. Stockfish might give 25% for each move (Bh4, Be3, Bd2, Bc1).


Hide the moves when clicking on a game the "games" pane of a database in ChessBase 15 I would like to hide the moves (circled in red), and arrows as well, in the "games" view of a chessbase (I am using chessbase 15) database when I clicked on one of the games, but I cannot find how to do it :

Would suggest performing a quick search via google
All information can be found at: http://help.chessbase.com/CBase/15
Hide Notation:
View Tab > Notation [Untick]
Hide Movement Arrow:
http://help.chessbase.com/CBase/15/Eng/index.html?moves_highlighted_with_a_yello.htm


Fool's Mate - As White? Fools Mate is simple as black, white opens right up, 2 moves, done.

But if you attempt to do this as white, once you move, black moves, you move, it's only check, there is no checkmate.

Is it possible to get a 2 move checkmate as white?

No.

With two moves as white, you can get out a maximum of one attacker to deliver a check.

With one move as black, there is no weakness you can create that leaves you unable to defend a check from any given attacking vector.


What's the problem with the Austrian Defense? So, I looked on the lichess analysis board and played around with it for a while, and I couldn't find any reason why 2...c5 isn't considered an accurate response to 1 d4 d5 2 c4.  Does anyone know why this is?

After 3. cxd5, any sensical black response is met with 4. dxc5. The time it takes for black to regain those pawns is lost on white's development, e.g. 4... e6 5. e4! exd5 6. Bb5+ Nc6 (or Bd7 7. Bxd7 Qxd7 8. Nd2) 7. Nc3.

White's opened up the center - favorable because of black's daft, dithering development - and obtains a game with winning chances.


Chess program for Linux/Unix console For reasons I'd rather not get into, what chess programs work well on the console (ie. does not require X Windows)? Something with an ASCII visualization of the board would be incredibly helpful (I'm still a chess newbie).

After installing GNU Chess run the command gnuchess from the terminal, it would look something like this:

~$ gnuchess
GNU Chess 5.07
Adjusting HashSize to 1024 slots
Transposition table:  Entries=1K Size=48K
Pawn hash table: Entries=0K Size=32K
White (1) : e4
1. e4

black  KQkq  e3
r n b q k b n r
p p p p p p p p
. . . . . . . .
. . . . . . . .
. . . . P . . .
. . . . . . . .
P P P P . P P P
R N B Q K B N R

Thinking...
Looking for opening book in book.dat...
Looking for opening book in /usr/share/games/gnuchess/book.dat...
Read opening book (/usr/share/games/gnuchess/book.dat)...
Loading book from /usr/share/games/gnuchess/book.dat.
40304 hash collisions...  Opening database: 265053 book positions.
In this position, there are 11 book moves:
 Nc6(71/77/22/32)  Nf6(54/113/88/113)  a6(75/3/1/0)  b6(67/11/3/9)
 c6(52/451/376/743)  d6(52/178/153/229)  e6(52/651/582/970)        g6(59/155/88/117)
 c5(56/2535/1691/2912)  d5(54/47/38/35)  e5(54/2518/1938/3369)

 c5(1322)  e5(1312)  e6(376)  c6(277)  d6(141)  g6(136)  Nf6(109)  Nc6(108)
 a6(76)  d5(76)  b6(70)

white  KQkq  c6
r n b q k b n r
p p . p p p p p
. . . . . . . .
. . p . . . . .
. . . . P . . .
. . . . . . . .
P P P P . P P P
R N B Q K B N R

My move is : c5
White (2) :


How big is the advantage for white in the "back-rank-game"? Consider a chess variant in which normal chess rules apply, with one exception. The player that is able to bring a piece or a pawn onto the opponent’s back rank, which would be the 8th rank for White and the 1st rank for Black, wins immediately. The move has to be legal and it ends the game, even if the opponent could mate on the next move.
On Liches some chess variants like King of the Hill, Atomic, and Three-Check can be analyzed. Can I easily adjust Stockfish or another chess program such that this new rule applies? Would have a big advantage in this game? Or can we even show that White has a winning strategy?

Well, since White has the first move, then White would always be trying to put a piece on the back rank, while Black is trying to catch up. So Black can eventually trade off all the pieces, and Black can keep opposition.
However, I'm not sure if this is a legitimate strategy. We would have to solve all possible positions before we know the actual result.


Is it legal to push the rook with the king when castling? I've gotten into the habit of pushing the rook over to the appropriate square using my king; that is, I take my king into my hand, I take it to the outer edge of the board, then push the rook to its right place using the king figure. Then, I place my king on the correct square.
I've not played in an over-the-board tournament before, and if I ever do so I'd like to know whether this is okay or whether it's a habit I need to lose.

As long as you -

only use one hand
touch the king first
don't do it in such a way as to disturb the opponent

then it is fine.


In the modern benoni, what should I do if this happens? Let's say the position looks like this:

[Title "Black to move"]
[FEN ""]

 1.d4 Nf6 2. c4 c5 dxc5

I usually do this:

[Title "Black to move"]
[FEN ""]

1.d4 Nf6 2. c4 c5 3. dxc5 e6 4. b4 a5

I have played this position only once, and won, but still this might repeat in a open tournament I might go soon, so I need help to figure this out, because in the videos I have seen for the Benoni, I can't really find this variation anywhere.

In the modern benoni, what should I do if this happens

Your continuation is the strongest in my opinion. I would advise you not to change anything.

  because in the videos I have seen for the Benoni, I can't really find this variation anywhere.

Of course, because it is weak. The best White can do after your move, in my opinion is this:

[Title "BenOni"]
[fen ""]

1.d4 Nf6 2.c4 c5 3.dxc5 e6 4.b4 a5! 5.b5 Bxc5

Here, I would aim for Bb2 + e3 + Nf3 + Be2 setup as White. Not ideal, but surely playable and the nearest towards equality I can get after that horrible b4...

If White tries to be "smart" about keeping the extra pawn, here is how I would play as Black:

[Title "BenOni"]
[fen ""]

1.d4 Nf6 2.c4 c5 3.dxc5 e6 4.b4 a5! $40 5.Bd2 ( 5.Qb3 axb4! 6.Qxb4 Na6! ) ( 5.Qa4 Na6! 6.a3? ( 6.Bd2? axb4 7.Bxb4 Nxb4! 8.Qxa8 Nc2+ 9.Kd2 Nxa1 $17 ) 6...axb4! $17 7.axb4?? Nc7! $19 ) 5...axb4! 6.Bxb4 Na6! $32 $40 7.Ba3 Nxc5 8.Bb2!? ( 8.Nf3? Rxa3! 9.Nxa3 Qa5+ 10.Qd2 Qxa3 $17)

Your only problem after b5 will be that you must play ...d5 which turns the game into positional battle. There will be no wild tactical positions anymore ( but still you will stand better ) so you will have to adapt psychologically to this fact ( tactical players hate "dry" positions and positional ones hate "wild" positions ). Try not to fall for this psychological trick. That is my last advice and a warning.

Good luck on the tournament!


Problem: Find White's second-to-last move For the following position to occur in legal play, with Black on move, what would White's second-to-last move need to have been?  Note that Black is checked by two pieces on the h1-h8 file and two more on the c1-h6 diagonal, and both the d2 bishop nor the h2 must have been at their present locations when check was given.
b/7P/6Pk/5P/4P/2PP/3B2KR/2Q1N2R w K - 0 1

This is my first effort at a retrograde analysis problem: I think the position shown is reachable via legal moves, but that there's only one possible way the last three half-moves could have transpired.  Did I formulate the puzzle "correctly"?  Could/should it be improved?  Would it be better with fewer pieces?
8/8/4Pk/3P/8/8/5QK/B w K - 0 1

In the latter formulation, I like the way the White queen is placed so that it could have moved from b2 or d4, unblocking the bishop, but for the fact that it would have been giving check if it had been in either of those places.
EDIT
Here's yet another formulation, perhaps a bit more subtle, but I think the solution is still unique.  Note that in this revision, White's last move is not certain, but the second-to-last move is.
[FEN "8/8/4Pk/8/8/8/8/B6K w - - 0 1"]

White's second to last move must be f5+.

So, this is what the position looked like before White's second to last move -

   [FEN "b7/6pP/7k/7P/4PP2/2PP4/3B2KR/2Q1N2R w - - 0 1"]

   1. f5+ g5 2. hxg6+

How to arrive at the solution -

In this position, it is Black to play and the Black king is checked by a double-battery of the two rooks and the bishop and queen. What was White's last move?

        [FEN "b7/7P/6Pk/5P2/4P3/2PP4/3B2KR/2Q1N2R w - - 0 1"]

Since it is a double check, it must be some form of discovered check. However, since we have a double-battery, it cannot be possible that the discovered check was caused by a move of one of the pieces involved in the battery, because the other piece in the same battery would have already been checking the Black king if such were the case. Thus, it has to be some other "piece". But no such piece can uncover two attacks. Thus, it must be a very specific case of a pawn capture, an en passant, where two lines are opened at the same time.

     [FEN "b7/6pP/7k/5P1P/4P3/2PP4/3B2KR/2Q1N2R b - - 0 1"]

     1... g5 2. hxg6+

In the above, position, we see that the Black king is checked by a battery of queen and bishop. The only way that could have occurred in this position is if White played f4-f5.

Thus, White's second to last move is f4-f5.


Why do many team championships have only 4 boards? Team championships in my area have 10 boards per side. Board arrangements have to follow the Elo ranking to avoid tactical arrangements (such as putting a very weak player against the other team's star to try to have more strength in other boards). I think that a team of 10 is representative of the strength of a team as a whole.

Why many national or international team tournaments have merely 4 players? Even if they are cheaper, they are not really representative of anything because just hiring a couple of strong players boosts the team strength, so what's the point of these tournaments with only 4 players (Olympics included)?

To be concrete, I'll focus on the Olympiad; the same ideas apply more generally.

So, the more boards we have on each team, the more representative the match will truly be of the respective populations. Now 4 players is indeed a small sample, but I am curious, what would your response be to someone who might pose the further question:

  "Why would a team championship have only 10 boards? That's not really representative of anything. I think that 20 boards would more appropriately represent the team's true strength."

We could of course push the same idea further and further. In principle, the only limiting factor for the number of boards would be the population of the smallest country participating, but of course things would become logistically impractical well before that.

Whatever you think of my turning your own question around at you, I think the gist of a simple answer lies in the last thing I said: different countries have vastly different sizes. If you want to have an elite team event that all countries can realistically compete in, you just can't have all that many boards. Russia would be happy to make it a 50-board competition, since they have a large population that is as chess-loving as any in the world. (According to the current live ratings at 2700chess, 12 of the top 43 players in the world are Russian.) But doing so would mean that far fewer countries have any real shot at doing at all well in the event; the caliber of player that, say, Israel would have to put on a Board 10 would be well below what Russia would be putting up.

Even with 4-person teams, only a handful of countries have done much medaling historically. But note that my example small country, Israel, got a silver medal in 2008 and a bronze in 2010. Things like that just wouldn't be possible with many more boards in play.


Why is there a 50-move rule and a 75-move rule? Logically, if 75 moves have been played, 50 moves would've also been played. This sounds ridiculous. It is like saying "I would buy this book if it cost under $60 and it costs under $40". So, what is the logic behind that?

From the FIDE Laws of Chess:

50-move rule:

  9.3 The game is drawn, upon a correct claim by a player having the move, if:
  (...)
  the last 50 moves by each player have been completed without the movement of any pawn and without any capture.

75-move rule:

  9.6 If one or both of the following occur(s) then the game is drawn: (...) any series of at least 75 moves have been made by each player without the movement of any pawn and without any capture.

(emphasis mine)

As you can see, the decisive difference is that the 50-move rule only applies if a player correctly claims it, while the 75-move rule applies independently of any claims. So, in the 50 to 75 move window, the players can claim for a draw, but don't have to (and play on). Only when the 75th move without pawn moves or captures has been reached, the arbiter may interfere and declare the game drawn.


Why can't I put Stockfish in SCID? I'm installing stockfish to be used on SCID. I followed these two tutorials, using Stockfish from the Stockfish website rather than from git.

https://www.chess.com/article/view/scid--stockfish
http://support.stockfishchess.org/kb/advanced-topics/compiling-stockfish-on-linux

I downloaded the engine binaries for Stockfish7 for Linux from

https://stockfishchess.org/download/

I read that you need to compile it first so I compiled the Stockfish engine with sudo apt-get install git g++. Tested it with make profile-build ARCH=x86-32 then I went to add the engine in SCID, with these settings:

name: stockfish
command: stockfish
directory: /home/user/Desktop/stockfish-7-linux/Linux/src/.stockfish
UCI on

But then it tells me that it is unable to start the program: stockfish.

That error is the default response for any error. If I typed in folders that don't exist and a file that doesn't exist, it gives that error too. What am I doing wrong?

In the line:

name:stockfish command: stockfish directory: /home/user/Desktop/stockfish-7-linux/Linux/src/.stockfish UCI on

Are you sure your exe file is called ".stockfish" and not only just "stockfish". Seems odd that you have a hidden exe file (even that it is possible)


Prove the pawn's color and the knight's position I was recently given a retrograde analysis problem to solve. Even though I've managed to at least intuitively get close to an answer, I don't know how to put it in the form of an acceptable proof. For example, I can see that the a5 bishop must be a promoted piece, but I don't see how it could have escaped White's pawn structure, unless f2 square was originally free and is now occupied by a Black pawn. But for the knight question, I don't see a clear way of distinguishing it. I am hoping that someone could show how to tackle such problems on a firm footing.
 [FEN "r2qk2r/1ppbp1p1/1pn2n2/b2pP3/3P4/2N3P1/PPP5/R2QK2R w - - 0 1  "]

We are told that neither kings have moved yet, that there's a pawn on f2 square, and a White knight on either the f3 or f4 square.
Prove the f2 pawn's color and whether the White knight belongs on f3 or on f4.

In both parts we know one to be true, which means it suffices to disprove one possibility for each and that settles the proof.

Part one:
Let's start by assuming the pawn on f2 is white and work our way up to see if we hit any inconsistencies. So here's our diagram:

 [title "Assuming f2 pawn is white"]
 [fen "r2qk2r/1ppbp1p1/1pn2n2/b2pP3/3P4/2N3P1/PPP2P2/R2QK2R w - - 0 1 "]

First trivial observation is the fact that the black bishop on a5 is a promoted piece as the original dark square bishop could never have escaped from f8. This means either the h or f pawn has promoted on g1 into a bishop that is now on a5. Having a white pawn on f2 also implies that the g3 pawn isn't the h-pawn having made a capture on g3 or else the promoted bishop could never have escaped white's kingside and reach a5, thus, g2-g3 is played at some point, and it was on g2 when black made the promotion (else no escape route). This in turn means the promoted black pawn must have been the h-pawn. But how did it get passed the h pawn? We know that white is down three pieces, the two bishops and the h-pawn. Additionally, we know that one piece was captured on b6 and one on g1 (for black's h-pawn to promote). Now both b6 and g1 are dark squares, but 'h2' pawn couldn't have been captured on either, nor could have the f1 bishop as it is a light square piece. Therefore, white must also have a promoted piece, as nothing else accounts for the missing captured piece, for instance a knight (or any other non-pawn) being captured on g1 by the h7 pawn and the h2 having promoted into a knight. So clearly the h pawn hasn't been captured but has instead been promoted. But therein lies the conflict: one of the h-pawns must have made at least two captures to get passed the other h-pawn. It couldn't have been the white pawn as black has only lost one piece so far, but it cannot be the black h-pawn either, because it must have then made 3 captures, 2 to get passed the white h-pawn and one last capture on g1 to promote into the a5 bishop. Knowing a capture on b6 has also taken place, this accounts for a total of 4 captures, but white has only lost 3 pieces at most. Thus, neither h-pawns could have legally promoted given that the f2 pawn is white, so our starting assumption must be wrong. We conclude the f2 pawn must be a black pawn.
Notice that throughout the analysis, the position of the knight either f3/f4, would have made no discernible difference on the resolution of the f-pawn's conflict, so we were safe to do the analysis independently. The reverse is not true, namely, the knight's position is very much dependent on the fact that the pawn on f2 is black.

Part two: Knowing now that the f2 pawn is a black pawn, let's take the most restrictive case and assume the knight is on f3 and perform a similar analysis to see if we hit any walls. So here's the corresponding diagram:

[title "Assuming the knight is on f3"]
[fen "r2qk2r/1ppbp1p1/1pn2n2/b2pP3/3P4/2N2NP1/PPP2p2/R2QK2R w - - 0 1 "]

It is the most restrictive consideration as it forces the f7 pawn to have made at least 2 captures to reach f2, because the white knight is assumed to be on f3, which means that f7 pawn must have just made a capture on f2 from e3 (that it reached from yet another capture). So far we have accounted for 4 white pieces having been captured and the h7 and h2 having promoted for black and white respectively. The only1 way the latter could have happened is if the h7 pawn (i) made two captures to go around the white h-pawn, or (ii) made only one capture from h3 (so taking something on g2) while white's h2 pawn still untouched. (i) is impossible by just considering the piece count, because so far there has been one capture on b6, two captures by f7 pawn and two by the h7 pawn, and that is already more captures than the number pieces white has lost. So only option is (ii): we know that the h7 pawn must have captured a non-pawn piece on g2 (as the g3 white pawn couldn't have been from either the h pawn which promoted, or the f2 pawn as black only lost one piece and that was the original f8 bishop on its original square). This in turn implies that g2-g3 must have been played by white before h7 captured on g2. But that means the promoted black bishop could not have escaped white's kingside via the g3-e5 diagonal anymore, therefore, it must have escaped from the f2-d4 diagonal instead, which settles the fact that the f7 pawn couldn't have captured a pawn on f2 (from e3), or else the bishop could never have reached a5, had there still been a pawn on f2 just presumably captured by black's f7 pawn.
Now here's the dilemma: what on earth happened to white's f2 pawn in all this? Can we logically account for it knowing black just took a non-pawn piece on f2 and there's a white knight lying on f3 (starting assumption)? It definitely couldn't have been the piece that the f7 pawn captured to reach the e-file either as white only made one capture and that was on f8, so f2-white-pawn couldn't have magically been on the e-file. Trivially, it couldn't have been captured on b6 or g2 either. It couldn't have been promoted either as it would have forced black's king to move (disallowed in the starting description). So f2 pawn couldn't have been promoted, or been accounted for by any of the four captures performed by black, but somehow it isn't on the board, thus, we can conclude that we've reached an inconsistency again, meaning there's no logical set of events that would legally reach the position given above with the knight standing on f3 which was our original assumption, so the knight must be on f4.

Come to think of it, there's a much shorter way of realising that the knight cannot be on f3 without focusing on the fate of the white f2-pawn: quick recap of captures: we know a dark square piece has been captured on b6, two non-pawn pieces captured one on e-file and one on f2, one non-pawn piece also captured on g2. But how many non-pawn pieces has white lost? The two bishops and another non-pawn (we cannot know which because we don't know what piece the h2 pawn promoted into) on the e-file. That's 3, so there's no other non-pawn left for black to have just captured on f2 (we already know it couldn't have been a pawn on f2 captured). And that's another formulation of the same inconsistency. Notice that if we are to assume that the non-pawn captured on f2 was a piece that resulted from the promotion of the f2-pawn, then it implies that the f2 pawn reached f7 with a check and was not captured by anything thus allowed to promote, but that's impossible as we know neither kings have moved yet, in other words, if the f2 pawn were to ever promote it must have gone passed the f7 square without being captured, which is impossible. Anyhow, let's end with the final correct diagram:

 [title "Solution"]
 [fen "r2qk2r/1ppbp1p1/1pn2n2/b2pP3/3P1N2/2N3P1/PPP2p2/R2QK2R w - - 0 1 "]

If you're interested in these kinds of discussions, have a look into the books of Raymond Smullyan, I even recall similar puzzles in one of his books but I have no copies at my disposal at the moment to check for you, maybe someone else can verify.

1: as the white pawn couldn't have made two captures to go around the black h pawn, because white has only made one capture in this game and that has been the f8 bishop on its original square.


Pinned Vs. Checkmate So say my queen is pinned in front of my king by the opponents rook. However if I move my queen to check their king it is certain checkmate, is that legal? I'm not sure because I'm intentionally endangering my king to be taken on the next move, but technically there won't be a next move since I checkmate my opponent.

Think of it this way:
Check mate is where nothing the opponent can do will save them from having you take their king on the next turn, so even if by putting their king in checkmate, you expose your own king, they can take your king before you can take theirs.
There is NO circumstance in which your actions put your own king into check without an opponent making a move.


Is it possible to integrate an opening book and/or endgame tablebase into a chess engine? If so, how? I'm currently attempting to program a chess engine for a club project; one where many different people could create different engines and they could play a tournament or something of that nature. As such, I'm not sure if it's appropriate for me to rely on a GUI like Arena to provide opening/endgame database support.

Is there a good way to integrate such databases into the engine itself? I am using UCI on Java to program the engine.

It's possible to integrate an opening book and/or endgame tablebase. Unfortunately there is no Java solutions, because chess engine programming is dominated by C/C++. Maybe you want to switch to C/C++? Your life will be easier.

Opening book

PolyGlot book (http://wbec-ridderkerk.nl/html/details1/PolyGlot.html)

Tablebase

Syzygy tablebase (this question has the details)

My recommendation

Unless you're an expert in programming, I don't think it's a good idea to work on Polyglot and Syzygy yourself. They're not written for beginners. GUI like Arena would be a better idea.


Structure-better structure or bishop pair in the endgame? Does the bishop pair compensate for doubled pawns if there are no rooks to attack with the bishops in the endgame?

More often than not, the Bishop pair will compensate for doubled pawns in an endgame.
Your unopposed bishop would have to be pretty bad (and therefore your overall position) if it's influence did not compensate.

In general doubled-pawns are not that bad if you have active piece play.  Look at the games from the Kasparov-Short world championship match.  Nigel Short repeatedly had doubled crappy looking pawns but because his pieces were active Kasparov was not able to capitalize on their weakness; this fact was well commented at the time.


How to play against an engine using scidb? I'v just installed the scidb chess database, and I can't figure how to play against an engine from there.Is this feature even supported ? If it is, how to use it ?

On this page, you can see that Scidb is not intended to be used to play against an engine.

You can use scidb for game analysis (click on the train button in the board tab), chessx to play against the computer (and game analysis too) and raptor chess interface or Jin to play on FICS (Free Internet Chess Server). These softwares all work on Linux. Other softwares are availble on Windows and OS X.


Where did Bobby Fischer live in New York? Where did Bobby Fischer live in New York in his younger years? Is anyone able to locate the street address where he lived? Is it 1059 Union Street in Brooklyn from the famous 1951 Helms letter to his mother?

Bobby Fischer lived here at Lincoln Place 560 in Brooklyn. The video shows the inside of the building. I was there in September, 2019.


What happened to the CCLA? I wonder what happened to the CCLA. Did the CCLA get folded into ICCF or USCF  or just go out of business?  Did it merge with yet some other chess group?

They appear to still be active.

https://www.serverchess.com/


Are there brute force engines which examine all possible moves to each depth? Are there chess engines that carry out brute force search, looking at all possible moves to each depth?  An engine like this could be used to generate for solutions to tactical puzzles where the key move gets pruned by engines with selective search.

The answer is yes and no.

http://www.gamedev.net/page/resources/_/technical/artificial-intelligence/chess-programming-part-iv-basic-search-r1171
Has a pretty good explanation on how chess engine works.

In Chess, for example, a typical branching factor in the middle game would be about 35 moves. That is, after every move, there will be around 35 possible valid moves.

Using a "smart brute force algorithm"  (aka Min-Max search), the time complexity of the algorithm is O( B^n ). That is, you need around that B^n operations n-ply search.

An 8-ply search of a chess position would need to explore about 1.5 million possible paths! That is a LOT of work. Adding a ninth ply would make the tree balloon to about 50 million nodes, and a tenth, to an impossible 1.8 billion! A typical game has 30-40 moves, so you will need to search for 30^35 - 40^35 positions.

Assuming your CPU is running at 3GHz, and it takes only one clock cycle to analyze one position, it will take more than 1x10^42 years to complete the search.  So short answer is no.

However, endgames with small number of pieces have been thoroughly analyzed, and can be determined if mate is possible.  By August 2012, tablebases had solved chess for every position with up to seven pieces (According to wiki http://en.wikipedia.org/wiki/Endgame_tablebase)


What positional play strategy should white adopt when fighting against the Philidor exchange variation? What are the key squares to control? What are ultra aggressive moves white can play at the advance level (expert or higher class)?

Why not follow that game? - he got a nice centralised position with pressure on d6. No need to take risks with "Ultra-aggressive" moves.


What serious use of en passant has been made recently? I'm a (very) amateur player and have seen the use of en-passant only a couple of times in club games. Chess books I've read (Soltis, Weeramantry, Pandolfini,etc.) feature hardly any games having en-passant pawn captures.

  Are there any recent championship games featuring a serious use of en-passant?

By "serious" I mean the outcome of the game depended substantially on this move.

I'll give an example that isn't from a world championship match, and isn't recent either. In fact, it doesn't even have an en passant capture in it. (Bear with me.) It does have a world champion playing in it, though, and more importantly, I hope it illustrates the following: even when no en passant capture actually occurs in a game, the fact that it is possible might be playing a very big role. This is not entirely unrelated to the old chess saying, "the threat is stronger than the execution."

In the game Alekhine - Yates (London 1922), we have the following position after black's thirty-first move:

[FEN "r3r1k1/2R3p1/2R1p2p/3pNp1P/p2P1K2/Pp2PP2/1P4P1/5b2 w - - 0 31"]

1. g3 1... Ba6 (1... g5+ 2. hxg6) 2. Rf7 Kh7 3. Rcc7 Rg8 4. Nd7 Kh8 5. Nf6 Rgf8 6. Rxg7! Rxf6 7. Ke5 7... 1-0 (7... Rff8 8. Rh7+ Kg8 9. Rcg7#) (7... Raf8 8. Rh7+ Kg8 9. Rcg7#)

Alekhine has boldly played his king forward with the idea of infiltrating the black position via e5. On the previous move, Yates had attacked his g-pawn with 31. ... Bf1 and Alekhine replies simply with 32. g3 to keep the pawn safe, ready to get back to business after that. Looking at the position, we can see that if Alekhine didn't have the en passant capture at his disposal, then Yates would be able to checkmate him with 32. ... g5. But since the rule is in effect, Alekhine's king is actually perfectly safe, and in a strong position to help his other forces attack.

Now Alekhine didn't have to play 32. g3 setting up this "pseudo-mate" possibility. But still the point is that the white pawn on h5 and its en passant threat plays a big part in Alekhine's suffocating clamp on the black position, and his successful invasion. Yates resigned only a few moves later, with Alekhine's king delivering the final blow on e5: 32. ... Ba6 33. Rf7 Kh7 34. Rcc7 Rg8 35. Nd7 Kh8 36. Nf6 Rgf8 37. Rxg7! Rxf6 38. Ke5 1-0.

Yates must lose his rook, because if either rook moves to f8, Alekhine has mate in two with 39. Rh7+ Kg8 40. Rcg7#. To reiterate the larger point:

  Many potential en passant captures that never actually occur, because the mere possibility of it discourages the other player from ever making the two-square advance in the first place, still play a major role in the game. This aspect - the most effective en passant is perhaps the one you never see - is one reason why, superficially, the en passant capture might seem like a less important/significant feature of chess than it actually is.


Knight constrained in advance Caro-Kann Recently, I've been playing the Caro-Kann exclusively against 1. e4, with good results. The one line that I find somewhat confusing is the advance Caro - specifically, where does the kingside knight go?

[FEN "rnbqkbnr/pp2pppp/2p5/3pP3/3P4/8/PPP2PPP/RNBQKBNR b KQkq - 0 3"]

After 3. e5 Bf5, the bishop gets developed outside the pawn chain, which seems good for black. Something that consistently gets me in trouble is that it seems like my g8 knight has no good squares to go to.

If the knight is developed to h6, it gets captured by the bishop, and after the pawn recaptures, black is left with doubled pawns and the option to castle kingside is more or less not available after this point (the g-file is now open).

The knight obviously cannot go to f6, as it would simply be captured by the advanced pawn.

The only reasonable possibility seems to be moving the pawn to e6, then moving the knight to Ne7, but where is the knight going from here?

Where the knights go depends on your pawn structure.

One option is to do the following, at some point

e7-e6
Nb8-d7
Ng8-e7
c6-c5
Ne7-c6

You get a French defence pawn structure with corresponding ideas.

You could go for the same pawn structure with a different knight setup.

e7-e6
c6-c5
Nb8-c6
Ng8-e7
Ne7-f5

Putting pressure on the d4 square.


Is chess.com's tactics trainer any good for actual tactical improvement? Daniel Naroditsky recommended using this to improve at tactics but I was wondering if it was in any way worse than using a book with tactics for example.

Its a fairly subjective question but their "learning" area is solid, the tactics tool is good for learning pattern recognition quickly. Most sites (lichess etc) have similar functionality.
Regarding how effective it is. Its dependent on you. If you learn better by doing. Probably better, if you like theory than book.


Playing a line in QGA from a QGD for White I was playing the other day a Queens gambit game, but it seems that my opponent had a very good prep against players like me who play with White like:
[FEN ""]
1.d4 d5 2.c4 e6 3.Nc3 dxc4

I usually go for a setup with Nf3, e3 (my bishop is locked and I fianchetto it on b2 later in the game). My line against QGA goes like this
[FEN ""]
1. d4 d5 2. c4 dxc4 3. Nf3 Nf6 4. e3 e6 5. Bxc4 c5 6. O-O a6 7.
b3 7... Nc6 8. Bb2 cxd4 9. Nxd4 Bd7 10. Nf3 Be7 11. Nbd2 O-O 12. Rc1 Rc8 13. Qe2 Qa5 14. a3
Rfd8 15. b4 Qh5 16. Nb3  *

Note that my opponent tricks me into playing a QGA with my knight on c3. It really annoys me a lot. I looked at some lines like this:
[FEN ""]
1.d4 d5 2.c4 e6 3.Nc3 dxc4 4. e3 a6 5. a4 (5. Bxc4 b5 6. Be2 Bb7 7. Bf3 ( 7. Nf3 Nf6 8. O-O
Nbd7 9. b3 c5 10. Bb2 Rc8 11. Rc1 Be7 12. dxc5 Bxc5 13. a4 b4 14. Nb1 O-O 15. Nbd2 Nd5 16.
Nc4 Be7 ) Bxf3 8. Nxf3 Nf6 9.O-O c5) 5... Bb4 6. Bxc4 Nf6 7. Nf3 b6 8. O-O Bb7 9. Qe2 O-O
10. Bd3 c5 11. dxc5 Bxc5 12. e4
Nbd7 13. Bf4 Nh5 14. Be3

I noticed that in the 5. a4 line Black is fine and has some initiative on my kingside which I also disliked. And in the 5. Bxc4 line I feel more comfortable playing it. The 5. Bxc4 b5 6. Be2 Bb7 7. Bf3 variation is a bit dry, and the 5. Bxc4 b5 6. Be2 Bb7 7. Nf3 variation I like it more  but the engine doesn't like it much!
The other option is to play 4. e4, which has a lot of theory in QGA and I also tried to avoid it by playing the other mainline in the QGA with Nf3 and e3. Playing the positions with 4.e4 are really hard imo. I tried to play e4 variation in QGA for 2 years and felt uncomfortable. I prefer to play the other system with Nf3 and e3. I would really appreciate some feedback on how to play a QGA the way that I like with Nf3 and e3 if black plays 1.d4 d5 2.c4 e6 3.Nc3 dxc4. I just don't wanna go to e4 variations unless you have a very easy reference that I can read about it. Thanks!

After 1.d4 d5 2.c4 dxc4 3.Nc3, 3...e6 is a pretty weak response due to 4.e4!. In your example, you can reach that exact position, where you basically take as much space in the center as you want for free. Sure it's not the type of position you're probably used to, but that's only because this one is actually a lot better and Black rarely allows you to reach it.
In other words, you'll succesfully achieve all the goals in the Queen's Gambit. You'll retake the c4 pawn and get a massive center with your e4+d4 formation all of this while keeping your king safe and your pieces developped!
Furthermore, an e5 reaction is one of the main resources Black has against our d4+e4 formation, so e6 was pretty much a lost tempo


How to avoid blundering in chess? I realize that there is no point in playing good chess if you end up blundering away a rook or a bishop. I end up blundering atleast once in two games which generally ends up with me resigning due to frustration. For eg., in a recent game, my opponent took my pawn with his bishop and I took another of his pawns in return. However, I didn't realize that after taking my pawn, he was also threatening my rook. Thus I blundered away my rook. Is there any technique to avoid making such blunders?

Playing good chess is still totally worth it. It's much easier to blunder in a deseprate position than in a good one. That being said, the main path towards stopping blunders is improving your tactical skills so you can detect threats more easily.
With enough time on the clock, you should always look for forced moves both you and your opponent may have (checks, captures, mate threats...) There's probably a reason for your opponent's last moves, so think of what new threats it creates.


Best chess theory books for beginners What are the best chess books regarding theory and such for beginners?

A book often recommended to beginners is Logical Chess: Move by Move by Irving Chernev. It contains 33 games with text explanations for every single move.

Dan Heisman also recommends other books in his web site, here are a few:

Chess: The Art of Logical Thinking - Neil McDonald
A First Book of Morphy by del Rosario
Most Instructive Games of Chess Ever Played - Irving Chernev
Chess Master vs. Chess Amateur - Euwe and Meiden

[edit] Here's a PGN file of Logical Chess that you can play through using a game viewer like Scid vs. PC while you read the book. Or you can just use a regular chess set.


Which titled players (IM or GM) have also been successful politicians? Garry Kasparov has been an unsuccessful politician and there have been several successful politicians who have also been quite good chess players, but have any of them achieved the IM or GM title?

Some candidates who didn't quite make it -

Nathan Sharansky, who according to his Wikipedia page, was the champion of Donetsk at 15, and who beat Garry Kasparov in a simul in 1996 has never even had a rating. He was in the Israeli parliament and government in the late 90's, round about the time he beat Kasparov.
I was sure that I read somewhere that Kirsan Ilyumzhinov who, as well as being FIDE president was also president of the former Soviet republic of Kalmykia, was a master level chess player. According to his Wikipedia page he was champion of Kalmykia at the age of 14. But according to his FIDE rating profile he has only ever played in one FIDE rated blitz in 2012 where he scored 2.5/7 against opponents with an average rating of 1954 for a performance rating of 1852.
British member of parliament, Angela Eagle, was according to her Wikipedia page, British girls under 18 champion in 1976 but, again, she never got a FIDE rating let alone a title.

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.


Delete annotations in pgn games Using ChessBase 13, I saved a bunch of games in PGN format. Is there a simple way to suppress the comments of all annotated games? I would like to avoid doing it one by one.

In Chessbase, copy the games to a temp database, right click the file, go to tools and select Unannotate db, then copy to the games to a pgn file.

Edited to note Unannotate doesn't work on pgn files directly.


Is there a chess GUI that gives an evaluation of each move? I'm looking for a chess GUI that shows the evaluation of each possible move rather than the top move.

In most GUIs you can set up top x moves. The reason why there is no program showing all moves, is that it would be terribly slow if you would make it show a lot of moves because of the engine.

All engines use some version of Alpha-Beta Search, without getting in the details of it, the point is, if a move is outside the interval of Alpha-Beta it is not examined further, so you can't really decide if it's right out of the window, or way off. If the engine wouldn't use this filtering, than it would need to check all branches, making it way too slow.

tl;dr

I don't think there is a GUI like that, if there is than the results it shows are completely bad, they would have the strength of a chess program from the 50s.


Some strange moves in Polgar vs Najer (2009) In the 2009 match between Judit Polgar and Evgeniy Najer in Richard Riordan GM Blitz the following strange(?) opening sequence of the Najdorf was played
[White "Judit Polgar"]
[Black "Evgeniy Najer"]
[Result "1-0"]
[fen ""]

1. e4 c5 2. Nf3 d6 3. d3 Nf6 4. d4 cxd4 5. Nc3 a6 6. Nxd4 e5 7. Be3 Be7 8. Nb3

Black refuses to take the white knight on both move 5 and 7 but why? I see no horrible threat if the capture is made.

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.


What is the main idea of 7.Qf3 in the Sicilian Taimanov? In the Sicilian Taimanov, after the opening moves

[FEN ""]
[StartPly "12"]

1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 e6 5.Nc3 Qc7 6.Be3 a6

7.Qf3 has become popular recently. I find it still a bit strange move however...What is (or are) the main ideas and perhaps tactical themes behind this move?

Main ideas:

Castling long as soon as possible
The Qf3 will most often move to g3 to pressure g7 and d6, and possibly help the break e4-e5.
Both central files are left for the rooks to apply maximum pressure (unlike after Qd2 or Qe2 developments)


When is it legal to castle moving the rook first? As a follow on from the question Is it legal to castle with a "ghost" rook: When is it legal (according to the FIDE Laws of Chess) to castle moving the rook first?

Unless this is a trick question, I'd say never:

3.8.2 [] This is a move of the king and either rook of the same colour along the player’s first rank, counting as a single move of the king and executed as follows: the king is transferred from its original square two squares towards the rook on its original square, then that rook is transferred to the square the king has just crossed.

The word then implies the king moves first, and the rook second. Also,

4.4 If a player having the move:
4.4.1 touches his king and a rook he must castle on that side if it is legal to do so
4.4.2 deliberately touches a rook and then his king he is not allowed to castle on that side on that move and the situation shall be governed by Article 4.3.1

That would imply that touching both king and rook (but not moving them) commits the player to castling; then, he/she could then move the rook first and only then the king, since that would give the same position on the board as the only legal play at that moment. Still, if I would see that as an arbiter, I'd have a word with the player about this.