Does practising Lichess coordinates help with reading chess books chess games faster?

I did the test and got 50 squares in 30 seconds. Part of the reason was that it takes some time to move the mouse, but it seems you're quite close to me in speed. I'm also a titled player that can read games from books, so I don't think this is where your problem is.
I'd suggest practicing blindfold chess. Just try playing it a bunch of times with someone, and over time you should get better at it. This helps with reading games from just the notation, since it's the same type of skill being applied.
You mentioned strong players are familiar with theory. This is true, and it includes knowledge like typical opening moves and pawn structures. If the game you are going through (without a board) reaches a position with a structure you're familiar with, or features sequences of moves you've seen many times before, then it's easier to keep track of. If you asked a strong player to read through a game where the 32 pieces start in completely random squares on the board, they would have a harder time since nothing will be familiar.
So to improve your knowledge of theory, the answer here is to just study books on openings, middlegames, etc. Obviously the main purpose of this would be to improve your chess as a whole, and the increased abilities to read games will come as a byproduct.


Why is offering draw not recorded but giving a check recorded?

Both recording checks and draw offers are personal preference, and neither is required in your notation.

I actually do record both checks as "+" or "++", and draw offers as "(d)". I know I am not the only one to note draw offers as I have friends, who do the same. I also record times.

The purpose of the notation is so you, or the arbiter, can play back over the game, and neither notation addition is really relevant for that purpose. I just like to know for my own edification if I go back later.

FIDE rules actually reference draw offers.

  8.1b The scoresheet shall be used only for recording the moves, the times of the clocks, offers of a draw, matters relating to a claim and
  other relevant data.


I don't think this is exactly what you're looking for, but it's at least a start.

The Analysis Board at chess.com allows you to paste in a FEN, make a move, then go to the Position Setup tab and copy the FEN.


How should one take advantage of the "premove" function on chess.com?

I think case 4: Your premove is illegal unless your opponent does something very specific but entirely expected, is the most common case that I've seen. Like you offering a trade, and regardless of what they take with (including if there is only one way they can take), there is only one specific way you want to take back.
As an example, IM and chess streamer Eric Rosen, when he gets to play the Stafford gambit as black (1. e4 e5, 2. Nf3 Nf6, 3. Nxe5), he always plays 3. ...Nc6, then premoves 4. ...dxc6. Because if that capture is legal, it must be because the white knight captured the black one, and in that case he always wants to take back with the d-pawn.
Also notable example of useful premove (and the converse of case 4, more akin to your case 2) was a drawn endgame where Carlsen had the black pieces during this his 2020 online tour (can't remember which game, or the exact piece placemens, sadly, but I believe it was KQP or KQ versus KRP). He had established a fortress and could premove his rook back and forth between two squares on the sixth rank. The only cases where such a move would lose the game were cases where performing that rook move would be illegal. He had only seconds left and no increment, so he couldn't wait and see what move his opponent would make.


Can White get a theoretical advantage against the Sveshnikov Sicilian in today's theory?

Let me answer your second question first: According to chesstempo db there are 6% less draws after 9.Bxf6 than after 9.Nd5, with White and Black each getting 3% more wins!
As far as a theoretical advantage: hoacin's comment is accurate.  Of course like all openings it is more about heading to the positions you like or are more comfortable with; thus many GMs would say that 3.Bb5 is the best move against the Sveshnikov.


Nice mate!
[Event "Forced Mate in 5"]
[Date "2020.11.05"]
[White "White"]
[Black "Black"]
[WhiteElo "2622"]
[BlackElo "2622"]
[Annotator "Bateman, David"]
[FEN "2r1qbnr/1b4p1/p2pNk1p/npp1pP2/4P1Q1/2PPB3/PP4PP/RN3RK1 b - - 0 1"]
[SourceVersionDate "2020.11.19"]

  1... Bc6 2. Bg5+ hxg5 3. Qxg5+ Kf7 4. Nd8+! Qxd8 5. Qg6+ Ke7 6. Qe6#

  The mate is identical if 4... Rxd8 is played instead. The key idea is to force a piece onto the d8 square in order to cover the two squares the queen on e6 cannot cover - f8 and d8.


Why 8...Na6 was played in the immortal draw?

I talked to National Master Dan Heisman about this game and according to him, the answer is really very simple:

At the time, black thought that 8...Na6 was the best move.  Black's intention was to control b4 and get to c5.  After that both sides played almost perfectly which resulted in a draw.

It is also possible that the game was actually made up, but this is hard to prove 140 years later.

Black probably would have played something else besides 8...Na6, but with no computer analysis at the time, it was thought to be best.


How come chess prodigies seem to start at a young age?

In pretty much any endeavor that requires one to develop or acquire complex sets of skills, be it chiefly intellectual or chiefly physical, starting young will generally be a huge boon simply because of the fact that younger brains are more plastic than older brains; they can more readily adapt to new sorts of tasks and information. Because of that fact, chess will be no different from sports or math or whatever, and those who rise to the very top will tend to have started quite young, as that makes much easier the ultimate task of acquiring the specialized knowledge and skills that are necessary in order to play chess with the very best. Even so, some remarkably strong players have indeed gotten relatively late starts.

Mikhail Chigorin first learned the rules of chess at the fairly late age of 16, and didn't really throw himself into chess until he was already 23-24. A quote from Wikipedia:

  He became serious about chess uncommonly late in life; his schoolteacher taught him the moves at the age of 16, but he did not take to the game until around 1874, having first finished his studies before commencing a career as a government officer.

All in all, I think Chigorin thus reasonably meets your criterion of having started after age 18. Technically, he was not a "grandmaster" in the sense of having that official FIDE title, but of course that's only because it didn't exist in Chigorin's day. He played two matches for Steinitz's world championship, and chessmetrics places Chigorin in the world's top 4 players throughout the 1890s (peaking at #2 behind Steinitz and Lasker at different times).

In addition, Howard Staunton apparently started playing chess only at age 26. Like Chigorin, he of course was not technically a GM in the modern sense of the word, but he is generally recognized as having been the strongest player in the world the 1840s, and is sometimes referred to as an "unofficial world champion" the way that Paul Morphy often is.


PGN-Extract output each game to a separate file with name like opponentA-opponentB.pgn

To a limited extent, you can do something like this already using the -Tp argument which selects games by a particular player. So:

pgn-extract -TpLeko --output Leko.pgn games.pgn

but there is not currently (2018.12.19) a way to have the file names generated automatically from the contents of the source file. Without a way to bound the number of players of interest this would require a lot of file opening and closing for a large input file. Some thought would also need to be given to how player names are mapped to file names.


You may do so only if the pawn is capturing one of the opponent's pieces; that is the only way a pawn ever moves diagonally. So here you can do what you describe:

[fen "3Rn3/k2P4/8/8/8/K7/8/8 w - - 0 1"]

1.dxe8=Q

But if you're talking about a situation like the following, then no, the pawn cannot move as you described:

[fen "3R4/k2P4/8/8/8/K7/8/8 w - - 0 1"]


This is not specifically for diagonals, but this is how I learned to visualize the board. I am not sure that I agree that you should be able to know what color a particular square is. I have been playing tournaments for 40 years this year, more than 30 at the master level, and I still do not think about the color of squares at all with regards to calculation (sure when it comes to making my bishop bad, and other positional elements). I just know where my pieces are, and with experience, where they can go. If I can visualize the former, then the latter is easy.

This is related to tactics, but specifically meant to be different. You can use a different book, but I started with Chernev's "Combinations, the Heart of Chess". The reason I used this book is that many of the examples are longer than normal, but not full game length, and they are interesting and fun. Some get to be 20 moves, or more.

Except maybe on short ones, you are not trying at all to solve them. ALL you are trying to do is keep the position in your head accurately, including sub-variations that are given. When you have visualized it well enough that you think you have it right, put it on a board, and see how well you really did visualize the position, especially, the final position. As you get better at this, you can use full-length games. Again, unlike tactics training, you are just trying to visualize where the pieces are.

Another fun book to do this with is Chernev's "1000 Best Short Games of Chess" since it starts with 4 moves and gradually goes up to 25 max. The only problem is both books I mentioned used descriptive notation, and if that is a problem, you will need to find other interesting shortish games to do this with.

Again, I suggest trying to visualize the whole board. If you do that, you will also see diagonals more clearly.


What is the history of the FICS mutual game history command>

hstat /o <opponent>

Please see this page for detailed explanation


"Parity" of "insuficient mating material"

It is a little unclear exactly what you are after, but the following portion of the question points to an area where something directly mathematical is going on:

  Sometimes you can see a checkmate, but you can never get to it because of the square the king is currently on. BUT you may only checkmate if black skips a turn.

This describes a situation known as mutual zugzwang (or, reciprocal zugzwang), which is where we have a position in which it is detrimental for either side to have a move. A prototypical example comes from K+P vs. K.

[fen "3k4/8/3KP3/8/8/8/8/8 w - - 0 1"]

1.e7+ Ke8 2.Ke6

White has no better than to allow this stalemate, whereas if Black had the move, White wins by 1...Ke8 2.e7 Kf7 3.Kd7 and queens.

Much more complicated examples exist, of course. In the following position, for instance, Black to move will lose, while White to move has no better than a draw:

[fen "8/q7/5q2/8/8/8/6QQ/k6K w - - 0 1"]

The above example was discovered by computer, actually. It is mentioned in Lewis Stillers' "Multilinear algebra and chess endgames" (PDF link), and that article gives a fair amount of background on the group-theoretic considerations involved. For further reading on the matter, you might try to get your hands on "Chess art in the computer age," American Chess Journal, 1(2):48--52, September 1993. I haven't seen the text myself, but this piece is referenced in Stillers' article, and it is by Noam Elkies, who is a world-class mathematician and a chess master (not to mention the 1996 World Chess Solving Champion). I know for sure that the article at least touches on the topic at hand, because it includes a composed study that is based on the mutual zugzwang above:

[fen "5Q2/5P1b/8/7K/8/1q4k1/1p4B1/8 w - - 0 1"]
[White "Elkies"]
[Black "Study"]

White to play and win (solution indicated in Stillers' article).


What are the ideas behind the Short variation in Advance Caro-Kann?

Here are a few observations regarding the line:

Replacing the 5th move with 5. Bd3 is a bad move. Black trades bad bishop for good with 5...Bxd3
Unlike the Nunn-Shirov attack (1. e4 c6 2. d4 d5 3. e5 Bf5 4. Nc3 e6 5. g4), White aims to get his King to safety by castling before any fireworks begin. To facilitate this the Bishop has to make way. We've already ruled out moving to d3, a fianchetto would be terribly slow and highlight the weakness of the bishop being restricted by its own pawns, and lastly there are no other safe squares
White knows that Black's pawn break ...c5 will use an extra tempo, and if it comes too soon then White's safe King and lead in development will favour the first player. Often Black will play an ...f6 break instead
Regarding a ...c5 break, White has the option to reinforce the pawn with ...c3, compared to the Nunn-Shirov attack where a knight restricts that advance
Again to restrict the ...c5 break, White will often develop the dark square bishop to e3 to overprotect d4. Black's minor pieces often settle on the following squares: ...Nb8-d7, ...Bf8-g7, ...Ng8-h6(!?)
Black does not fear the bishop taking the h6 knight. The Bishop pair and semi open g-file provide ample compensation for the doubled h-pawns, which are not easy to attack. Often White will have to un-double these pawns for defensive purposes
White often tries to gun down the light square bishop with the f3 knight, to win the 2 bishops. Black often plays ...h5 to gain king side space and give the light square bishop a flight square
Extra: White also plays for the c4 break to dissolve the centre. Black often gives White an isolated Queen's pawn with ...dxc4, which often results in White losing time with the recapture Bxc4. Thus ensues the dynamic contest of White's semi-open files and potential piece play in the middle game compared to Black's solid structure that will favour the second player in the endgame

If you want to know (a lot) more, then check out The Caro-Kann: Move by Move by Cyrus Lakdawala. Also, this chess.com link has a discussion on the line: http://www.chess.com/forum/view/chess-openings/advance-shirov-vs-advance-short-in-the-caro-kann


Perpetual check isn't a thing any more. But the idea is that one side demonstrates that they can keep putting the opponent's king in check, regardless of what the response is. Sooner or later it will turn into a threefold repetition or run afoul of the fifty move rule.


First, I don't think that there is any doubt that black has significant compensation, but clearly, black is still trying to hold this, not win it when talking two computers playing each other. I believe that between two humans, I would probably prefer black.

If you have an eval that says +.63 for white, but black is down two pawns, you have to realize that it means that black has roughly 1.37 in positional compensation.

White obviously has the two pawns, but black has the two bishops in a relatively open position, is ahead in development with the Rd8 already controlling the file, and h4 is a target that at the very least can be used to gain a tempo. Lastly, the g4 square is a wonderful spot for the Bc8, and helps control the open file. Also, the Rf1 is poorly placed, and the Bc1 currently does not have a bright future. One of the extra pawns, although I am going to trade it off, is currently doubled.

I analyzed this using a computer, and it is a VERY difficult position to get a handle on because so many of the moves are almost equal in the evaluations. In each case, what I did was let it get to a depth of 33-37 using Stockfish 11, and then I would advance the game by a move and force in the best move, and then let it get to a depth of 33-37 again, and so on. So, by the time I got to the 16th move of the variation, it was still looking 35+ ply ahead.

Here is the variation I found, and I have notes as to why the moves are being played. At the end, it is still only +.41, and despite the two pawns minus, it is hard to believe that white can win due to black's incredible activity, and the Kg8 will enter the game soon.

 [FEN "r1br2k1/pp3pbp/6p1/4P3/5P1P/2N1P3/PP4P1/R1B1KR2 b Q - 0 1"]

 1... f6 2. e4 Bg4 3. e6 (3. exf6 Bxf6 4. g3 Bxc3+ 5. bxc3 Rd3 6. Kf2 Re8 7. e5 Rc8 {and black is almost winning...f5 is already the only move so white can play Bf4 next defending g3.}) Bxe6 4. Kf2 Rd3 (4... Bg4 5. Be3 Rd3 6. Rfe1) 5. Rd1 (5. Be3 Bg4 6. Rac1 Re8) 5... Rxd1 6. Nxd1 Rc8 7. Nc3 f5 8. e5 Bf8 {Ba3 threat.} 9. Bd2 a5 {Idea a4-a3.} 10. Ke1 {To prophylactically protect the Bd2 after a4; Na4 Rc2} Bc5 11. Rd1 Be7 $1 {Only after a2 is undefended does this combined with a4 work.} 12. g3 a4 $1 13. Nxa4 (13. a3 Bb3) 13... Rc2 14. Rc1 Rxc1+ 15. Bxc1 Bxa2 16. Nc3 Bc4 $14 {Nd1 +.41.}


Why doesn't FIDE recalculate ratings match after match?

The ECF only update grades once every 6 months and their main reason is practicality. If they were to update grades after every game, it would require team captains and tournament organizers to submit game results immediatley after the game was played. In reality, results are only submitted a few days or weeks after the game, making instant grade updates difficult. With regional leagues it is even worse, with many leagues only submitting the entire grading period's result in bulk once at the end of the period.

I suspect Fide has a similar reasoning. Most Fide rated games are not between super grand masters in highly visible professional tournaments, but amongst amateur players on a club or school level relying on volunteers to make it work. It would be impractical to expect of these individuals to comply to a rigid regime of correctly submitting game results continuously - the number of mistakes and complaints would be enormous. By only updating grades monthly, they allow up to a month's leeway on results submission.


Where am I wrong?

None of "the world's best intellectuals" spend much time playing chess. The only strong (GM strength) chess player who qualifies as an intellectual is Dr John Nunn GM who graduated with a first in mathematics from Oxford University at the age of 18.

  Why do people even play chess?

The best answer to this was given by Siegbert Tarrasch who famously said:

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


What to play after 4.d3 in the Two Knights for Black

If you really want an unsymmetrical position, don't play 1...e5.  White has many move order options to steer the game into a relatively quiet position in double king pawn openings.

There are a few things that you can consider in order to keep the game interesting.  First and foremost, if you must win at all costs, I would recommend playing 4...Be7 in order to keep all of the pieces on the board.  Black will be cramped for some period of time, but since all of the pieces remain on the board there is plenty of play left in the position.

If you just want open lines, then consider playing an early d5.  For example:

[FEN ""]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d3 Bc5 5.c3 O-O 6.O-O d5

The downside is that lots of pieces can get traded, but black has easy development plans with Bg4, Nb6, and f7-f5 once the white bishop moves off of the diagonal.

With all that said, although black can have a hard time creating immediate imbalances, white has a very hard time getting an advantage with the Italian game, so generally keeping the pieces on the board and accepting equality will let the better player outplay his or her opponent and win.


How much time on my clock do I have to lose before it is legal to stop notating?

According to the FIDE Laws of Chess:

  Article 8: The recording of the moves

  8.4 If a player has less than five minutes left on his clock at some stage in a period and does not have additional time of 30 seconds or more added with each move, then for the remainder of the period he is not obliged to meet the requirements of Article 8.1.

Article 8.1 is the one that states that players need to keep record of the moves and what the players must and must not write to the scoresheet.

So:

  When I play in tournaments, I do not know when it is legal to stop chess notation.

You may stop notating when your clock shows less than five minutes and you get no increment or increment of less than 30 seconds. You have to start again at the start of the next period, that is, when more time is added to your clock (not the increment but for example at move 40).

  Also, if my opponent stops notating, is it okay for me to stop notating as well?

It makes no difference whether your opponent has to write the moves or not.


Would it be offensive to a chess coach to hire another titled player just to play training games with?

You are the customer, therefore you can spend your time and money as you see fit.

From your coaches' point of view, they would prefer it if you didn't use the services of another player. After all, any professional who is paid on an hourly basis would prefer to have a monopoly on a revenue stream and work 100% of the hours that you are paying for. But that is your coaches' problem, not yours.


How do I become better at counter play when I'm down in material?

Counter play, especially when down material, is often about creating dynamic chances. So you should probably work in that area:

Study the games of some attacking geniuses like Tal, Shirov, Morphy, Anderssen.
Work through some good books on attacking chess.
Play some gambits in training games.
Train tactics, but thats a given anyway.


Use the king to keep the black king in the corner and force Black into zugzwang:

[FEN "8/8/6R1/8/8/4K2p/7k/8 w - - 0 1"]

1.Kf2 Kh1 2. Re6 Kh2 (2... h2 3. Re1) 3. Rh6 Kh1 4.Rxh3


Is there any method to determine if the weaker side in KQPKQ has a perpetual check?

Whether there is a draw in hand depends on both the rank and file of the pawn in the following analysis.
The following as an analysis quoted in Wikipedia's article, queen and pawn versus queen endgame. All quotes and diagrams are taken from Wikipedia. Wikipedia cites table base analysis by the chess computer Belle from 1985, alongside John Nunn, Reuben Fine, Pal Benko and others.
Key For Diagrams

Black king on white dots: win with White to move, draw with Black to move; on black dots – win with either to move; other squares – draw

Rook Pawn

A rook pawn needs to be on at least the sixth rank to have decent winning chances

Knight Pawn

A knight pawn should be on at least the fifth rank to have good winning chances. A knight pawn on the fifth rank has better winning chances than a rook pawn on the sixth rank. There are two reasons for this:

The king has squares on the adjacent rook file to try to avoid perpetual check
The exchange of queens is less likely to lead to a drawn king and pawn versus king endgame

Bishop Pawn

A bishop pawn offers the best winning chances. One reason is that there is no drawing zone in the opposite corner for the black king if the pawn is on at least the fourth rank. If the pawn is on the fifth rank the defender's chances are small unless the king is in front of the pawn. A pawn on the sixth rank wins unless the defending king is in front of the pawn

Centre Pawn

A central pawn has better chances to win than a rook pawn or knight pawn, but not as good as a bishop pawn. As with the bishop pawn, there is no drawing zone for the defending king in the opposite corner. It is better for the defending king to be on the "short side" of the pawn rather than the "long side"


How come it's actually Black with the advantage here?

White's actually quite close to busted in that position after 16...Qd5. Of the two points you bring up, note that White doesn't actually control the e-file because Black is ready to play a rook to e8 and drive White's major pieces away. The knight on g5 looks good, but it's also vulnerable to being kicked by ...h6 and it's not threatening anything yet. Otherwise, White's king is dangerously exposed on the long diagonal since Black already has a bishop on the diagonal and since White no longer has f3. Finally, White's queenside is undeveloped. Granted Black's a8-rook isn't developed either, but it can jump into the fray much quicker.
Consider, checkmate is threatened on g2 and White has only a few ways to defend it:

17.Re2 is the easiest to refute because 17...Rfe8 wins either a rook or the queen.
17.Nf3 is also terrible. Again Black plays 17...Rfe8, and after 18.Qc7 (or where else is White going to put the queen?) Black plays 18...Rxe1 19.Nxe1 (forced) 19...Rae8 (developing with tempo) 20.Nf3 (still forced) Re2. Black's pieces are overwhelming White's king while White's queen, bishop and rook are all spectators. An immediate threat is 21...Rxg2+ 22. Kxg2 Qxf3 and checkmate.
That leaves 17.Qe2, which is the least evil but still not good enough. Black again plays 17...Rfe8, forcing 18.Ne4 (all other moves either lose material or get mated on g2), and then the Knight is pinned. Black has a variety of promising ideas such as 18...Qf5 intending to take on e4, or 18...Nd7 intending ...f5 to win material.

By the way, it's striking how much of Black's advantage stems from the fact that White's queenside is undeveloped, and by extension the rook on e1 is undefended (once ...Rfe8 kicks the queen away). Move White's c1-bishop to d2, and Black's advantage drops to about -1.0.


h6 as a prophylactic move in the opening

The thing with h6 is that, in the opening, the move has one purpose for Black: prevent White from placing a piece on g5.

The drawbacks of the move are that:

It's a tempo investment. Tempos are important not to waste in, for example, open positions, where it is good to get your pieces out to active squares as early as possible.
It potentially weakens your kingside if you decide to castle short. A pawn on h6 can become a target for a piece sacrifice if White decides to launch a kingside attack.

So basically, you shouldn't make the move h6 out of habit. It should be played after carefully considering the consequences of letting an enemy piece reach g5. Does White even want to play a light piece to g5? If not, then why waste the tempo?

This of course applies to the pawn push h3 in the opening for White, and also in some sense the pawn pushes a3 and a6, although the latter two can often have other purposes as well, as in the Sicilian, for example.


What are the main tournaments in the chess world?

If you wish to know about tournaments for top players, I would direct you to 2700 chess (scroll down under the list of players).

If you consider a " big tournament" an open tournament with let's say 100 participants (and maybe 1 or 2 of them are top players), then do a search in some comprehensive chess calendar, e.g.: chess-calendar.eu or FIDE's calendar.

Not just the biggest tournaments affect player's FIDE rating, almost every small tournament can do that, too (all FIDE needs is some... money).

Therefore the only exceptions I can think of are friendly matches and alternative chess tournaments (Fischer's chess, Basque chess etc.).


Since my Stockfish fork for fairy chess variants already supports Almost Chess, I added Sort of Almost Chess with both sides having all promotion options (which is what you seem to imply in your question).

I ran a search on the given position up to depth 50 with the commands below:

setoption name hash value 1024
setoption name multipv value 30
setoption name UCI_Variant value sortofalmost
position fen 7Q/8/6K1/8/8/1k6/6P1/c7 b - - 0 1
go depth 50

The results below state that white is winning (latest in 23 moves) irrespective of black's next move. Going through some of the variations in the output it seems relatively clear that the chancellor has no way to give a perpetual, so white is able to advance the pawn and finally either promote or force the exchange of queen and chancellor.

info depth 50 seldepth 47 multipv 1 score mate -23 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1a4 h8f6 b3a2 f6e6 a2b2 e6e2 b2c1 e2e3 c1c2 g6f7 a4a5 e3e2 c2b3 e2d3 b3a4 d3d4 a4b3 d4b6 b3a4 b6a5 a4a5 g2g4 a5a6 f7f6 a6b7 g4g5 b7a7 g5g6 a7a6 f6e5 a6b5 g6g7 b5c4 g7g8q c4c3 e5e4 c3c2 e4d4 c2b2 d4c4 b2c2 g8g2 c2d1 c4d3 d1e1 g2g1
info depth 50 seldepth 47 multipv 2 score mate -23 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1e1 h8b8 b3a2 b8a7 a2b3 a7b6 b3c4 b6a6 c4b4 a6d6 b4c4 g2g4 e1a1 d6c6 c4b4 c6e4 b4b3 e4d3 b3b2 d3d4 b2a2 d4a1 a2a1 g6f5 a1b2 f5e5 b2b1 g4g5 b1c1 g5g6 c1d1 g6g7 d1e2 g7g8q e2f3 g8b3 f3e2 e5e4 e2f2 e4f4 f2g2 b3c2 g2f1 f4f3 f1e1 c2c1
info depth 50 seldepth 45 multipv 3 score mate -22 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1g1 h8b8 b3c2 b8c7 c2d3 c7d6 d3e4 d6b4 e4d3 g2g4 g1h1 b4d6 d3e3 d6e5 e3f2 e5f4 f2g1 f4c1 g1h2 c1h1 h2h1 g6f5 h1g2 g4g5 g2f2 g5g6 f2f3 g6g7 f3e3 f5e5 e3d3 g7g8q d3e3 g8b3 e3e2 e5e4 e2f2 e4f4 f2g2 b3c2 g2f1 f4f3 f1e1 c2c1
info depth 50 seldepth 45 multipv 4 score mate -22 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1f1 h8f6 f1g3 g6f7 g3h1 g2g4 h1h7 f7g6 h7h3 g4g5 b3a3 g6f7 a3b4 g5g6 h3h6 f7e6 h6g4 g6g7 b4c4 e6f7 g4g1 f6c6 c4d3 c6g6 g1g6 f7g6 d3e4 g6f6 e4f4 g7g8q f4e4 g8c4 e4f3 c4d3 f3g2 d3e2 g2h3 e2f2 h3g4 f2e3 g4h4 f6f5 h4h5 e3h3
info depth 50 seldepth 45 multipv 5 score mate -22 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1d1 h8f6 b3a4 f6c6 a4b4 c6b6 b4c4 g2g4 d1e1 b6d6 e1a1 d6c6 c4b4 c6e4 b4b3 e4d3 b3b2 d3d4 b2b1 d4a1 b1a1 g6f5 a1b2 f5e5 b2b1 g4g5 b1c1 g5g6 c1d1 g6g7 d1e2 g7g8q e2f3 g8b3 f3e2 e5e4 e2f2 e4f4 f2g2 b3c2 g2g1 f4f3 g1h1 c2g2
info depth 50 seldepth 43 multipv 6 score mate -21 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1c1 h8f6 b3a3 f6d6 a3b3 d6d7 c1c5 d7d1 b3a2 d1d2 a2b3 d2e3 b3b4 e3c5 b4c5 g2g4 c5d6 g6f7 d6c6 g4g5 c6d7 g5g6 d7d6 f7f6 d6d5 g6g7 d5e4 g7g8q e4e3 f6e5 e3f3 g8b3 f3e2 e5e4 e2f2 e4f4 f2g2 b3c2 g2g1 f4f3 g1h1 c2g2
info depth 50 seldepth 43 multipv 7 score mate -20 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1a6 h8f6 a6a4 g6f5 b3a2 f6e6 a2a1 e6e1 a1a2 e1d2 a2a3 d2d3 a3b4 d3e4 b4b5 e4a4 b5a4 g2g4 a4a3 f5e5 a3b2 g4g5 b2b1 g5g6 b1c1 g6g7 c1d2 e5e4 d2c2 e4d4 c2b3 g7g8q b3b2 d4c4 b2c2 g8g2 c2d1 c4d3 d1e1 g2g1
info depth 50 seldepth 41 multipv 8 score mate -20 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1c2 h8b8 b3a2 b8a8 a2b3 a8d5 b3b2 d5e4 c2c1 e4b4 b2c2 b4c5 c2b1 c5c1 b1c1 g2g4 c1d2 g6f5 d2d1 g4g5 d1e2 g5g6 e2e3 g6g7 e3e2 f5e5 e2e3 g7g8q e3f3 g8b3 f3e2 e5e4 e2f2 e4f4 f2g2 b3c2 g2g1 f4f3 g1h1 c2g2
info depth 50 seldepth 39 multipv 9 score mate -19 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1a5 h8b8 b3a2 b8d6 a5a4 d6d5 a2a3 d5d3 a3b2 d3b5 b2a3 b5a4 a3a4 g6f6 a4b5 g2g4 b5b6 g4g5 b6a7 g5g6 a7a6 f6e5 a6b5 g6g7 b5c4 g7g8q c4c3 e5e4 c3c2 e4d4 c2b2 d4c4 b2c2 g8g2 c2d1 c4d3 d1e1 g2g1
info depth 50 seldepth 31 multipv 10 score mate -15 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1a3 h8h3 b3b4 h3a3 b4a3 g2g4 a3b4 g4g5 b4c5 g6f6 c5c6 g5g6 c6d6 g6g7 d6c5 f6e5 c5c4 g7g8q c4c3 e5e4 c3c2 e4d4 c2b2 d4c4 b2c2 g8g2 c2d1 c4d3 d1e1 g2g1
info depth 50 seldepth 31 multipv 11 score mate -15 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1a2 h8g8 b3b2 g8a2 b2a2 g2g4 a2b3 g4g5 b3b4 g6f5 b4b5 f5e5 b5b6 g5g6 b6c5 g6g7 c5c4 g7g8q c4c3 e5e4 c3c2 e4d4 c2b2 d4c4 b2c2 g8g2 c2d1 c4d3 d1e1 g2g1
info depth 50 seldepth 31 multipv 12 score mate -15 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1b1 h8b8 b3c2 b8b1 c2b1 g2g4 b1c2 g4g5 c2d3 g6f5 d3e2 g5g6 e2e3 g6g7 e3e2 f5e5 e2e3 g7g8q e3f3 g8b3 f3e2 e5e4 e2f2 e4f4 f2g2 b3c2 g2g1 f4f3 g1h1 c2g2
info depth 50 seldepth 29 multipv 13 score mate -14 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv b3a2 h8a1 a2a1 g2g4 a1b2 g4g5 b2a1 g6f6 a1b1 g5g6 b1a2 g6g7 a2b2 g7g8q b2c2 g8g3 c2b2 f6e5 b2a2 e5d4 a2b2 g3c3 b2a2 c3b4 a2a1 d4c3 a1a2 b4b2
info depth 50 seldepth 21 multipv 14 score mate -10 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1a7 h8b8 a7b7 b8b7 b3c4 g6f5 c4c5 f5e5 c5c4 b7f3 c4b5 f3c3 b5a6 e5d6 a6a7 c3b2 a7a8 d6c6 a8a7 b2b7
info depth 50 seldepth 19 multipv 15 score mate -9 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1h1 h8h1 b3c3 h1h4 c3b3 h4d4 b3c2 g6f5 c2b3 f5e4 b3a3 e4d3 a3b3 d4b6 b3a2 d3c2 a2a1 b6b1
info depth 50 seldepth 19 multipv 16 score mate -9 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv a1a8 h8a8 b3b4 a8c6 b4b3 c6b5 b3c2 g6f5 c2d2 f5e4 d2c3 e4e3 c3c2 b5b4 c2c1 e3d3 c1d1 b4b1
info depth 50 seldepth 17 multipv 17 score mate -8 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv b3b4 h8a1 b4c4 g6f5 c4d3 a1a4 d3e2 a4d4 e2f1 f5g4 f1e2 g4g3 e2e1 g3f3 e1f1 d4a1
info depth 50 seldepth 17 multipv 18 score mate -8 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv b3a3 h8a1 a3b3 a1d4 b3c2 g6f5 c2b3 f5e4 b3a3 e4d3 a3b3 d4b6 b3a2 d3c2 a2a1 b6b1
info depth 50 seldepth 17 multipv 19 score mate -8 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv b3c2 h8a1 c2d3 g6f5 d3c4 a1a4 c4d3 f5f4 d3c3 f4e3 c3b2 e3d3 b2b1 d3c3 b1c1 a4a1
info depth 50 seldepth 17 multipv 20 score mate -8 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv b3a4 h8a1 a4b3 a1d4 b3c2 g6f5 c2b3 f5e4 b3a3 e4d3 a3b3 d4b6 b3a2 d3c2 a2a1 b6b1
info depth 50 seldepth 17 multipv 21 score mate -8 nodes 860106805 nps 1814762 hashfull 355 tbhits 0 time 473950 pv b3c4 h8a1 c4b3 a1d4 b3c2 g6f5 c2b3 f5e4 b3a3 e4d3 a3b3 d4b6 b3a2 d3c2 a2a1 b6b1


If a pawn promotes to a checking piece while also revealing a check, it is a double check?

Yes, a double check is when two pieces give check at the same time. It doesn't matter how you got to that position. As to whether there's an error on that wiki, it's probably best to try to ask its author. Maybe they can provide the full list of positions for you to compare.

I can think of two ways of giving double check while promoting. One is where you have say the black king in front of the white pawn, and a white queen or rook behind the pawn, and the pawn promotes with a capture, ending up as a new white queen or rook next to the black king. The other is where say the black king is on the seventh rank, white has a rook or queen on the other side of the pawn, and White promotes to a knight, queen or bishop giving check.


How can chess be applied to other fields like politics or football tactics?

Here are some example areas I think can of (definitely not limited to just these):

Attacking your opponent at different parts of the board simultaneously. This can be translated to pressuring your real world opponent in different ways at the same time.
Identifying weaknesses.
A sense of danger. I don't know how well this would translate into the real world, but in chess you develop an intuition for what's really a danger and what's not.
Calculation skills, both for thinking far ahead (depth) and considering a number of options your opponent could go for (breadth). This has obvious applications when trying to figure out what your opponent will do in politics, football, etc.
Distributing and maximizing resources. In chess you need to figure out where to put your pieces, based on where they are most needed/can be most effective.

However, correlation doesn't necessarily imply causation. Getting good at chess might have given someone these real world skills; or, they could already have these skills and that's why they're good in both chess and certain real world activities. A likely possibility is that someone is already fairly strategical, and then playing chess amplifies their abilities.


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

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

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

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

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

Current Laws of Chess are here.


An offline alternative to lichess.org's online analysis engine

I will strongly recommend SCID. Its open source and very feature rich.


Why doesn't the computer take my knight?

If I understood correctly, the knight was on c6 and you play Nf4 whilst having a pawn on e5 still (which is important as it prevents f6 by black after gxf4 Bh4+). In this case, gxf4 is not necessarily the best as it leads to the exchange of B+N for a rook an a pawn (see below), which gives white some chances, despite it still being better for black.

 [title "Game position before Nf4, white to move"]
 [fen "3r4/p1p1kp2/1pn1b2p/4P1p1/P3p3/2P1P1BN/2P2PPP/R5K1 w - - 0 1"]

 1. Nf4 gxf4 2. Bh4+ Ke8 3. Bxd8 Kxd8 4. exf4

Instead, considering that white's lacking both coordination and activity, and the fact that black has all pieces centrally established and controls the only open file, it might be simpler (and even best) to not create an imbalance (like the line we saw above) and aim to maintain the assured edge by avoiding an over simplification that might be hard to judge and playing against white's shattered queenside pawn structure. Here's one possible continuation to exemplify:

 [title "Game position before Nf4, white to move"]
 [fen "3r4/p1p1kp2/1pn1b2p/4P1p1/P3p3/2P1P1BN/2P2PPP/R5K1 w - - 0 1"]

 1.Nf4 Nxe5 2.Ne2 Kf6 3.Nd4 Rd5 4.Kf1 Rc5 5. Ra3 Bd7


9...c5 seems too early to me.  Castling into safety is better.

10...Ba5 is reasonable.  It's often played in the Marshall Gambit of the QGD.
I prefer Bd6 to maximize it's potential and to protect the center dark squares.

11...Nd7 is fine.  I think c5 first is wrong as after 12. dxc5 Nd7 13. Rd1 (or 0-0-0) the threat of b4 forces you to give up your two bishop advantage.

12...b5 looks very interesting; opening the lines even at the cost of a pawn is worth it.  c5 is also fine,  I would consider e5, just to get my LSB to e6.

13...Qf4+ seems best, as it puts more pressure on white--especially the f3-knight.  13...Qe7 may have problems after 14. d5.  This requires much calculation with many nuances.

I definitely prefer 14...b6. The LSB needs to get active and out of the way to the rooks.  However, you must still watch for dxc5, with a discovered attack on the knight (after the bishop moves), and d5 with problems getting your pieces to an effective square.

On move 7, opening the center while behind in development is not recommended.  Qd8 is better on general principles, but hard to make OTB.  7...Bb4 is an option.


Why doesn’t the computer like my odd queen trade?

Losing an exchange is itself enough to make the move weak.
You go from being up R+P for N, which is a winning advantage,
to up just one pawn with opposite color Bishops, which
could often be drawn.

The move is also weak because you let White off the hook:
you were on the attack against White's exposed King,
so the trade of Queens made the position "easier to play" --
for White.  Instead of giving up material
just to trade your active Qf6 for White's passive Qd1
(it has only one move!), try involving the in the attack
your Nc6 (your only piece not already aiming at the Ke1),
or trading it for one of White's defenders.
Either 17...Ne5 or 17...Nd4 should win quickly:

17 ... Ne5 actually threatens the Nf3: after Nxf3+, both defenders
(Nd2,Be2) will be pinned.  What's more, the Nf3 itself is "pinned"
in that if it moves (say 18 Nxe5) then 18 ... Qf2 is mate!
White has no real defense; if 18 Kf1 then simply Nxf3 19 Bxf3 Rxd2
20 Qxd2 Qxf3+ and mate.

17 ... Nd4 adds the threat against the Be2; now White can defend
for a move with 18 Nxd4, but 18 ... Qxd4 restores the threat Qf2#
and White might as well resign (19 Qc1 Qf2+ 20 Kd1 Qxe2#).

After 36 Rxf6+? Rxe4 simply wins a piece: if 37 Kxe4 then Black takes on f6,
and if the Rf6 moves then Rxb4.  The alternatives "Kg8 or Kh8"
are not equivalent: 36 ... Kh8?? would have allowed 37 Rf8#!


Where can I find databases of tactical problems, categorized and ranked by difficulty?

This kind of thing isn't done by hand, but by computer programs. It is not too difficult to run some program on a game database and extract all positions suitable for a tactical exercise.
Sorting them by difficulty will be done over time, when statistics accumulate how often they are solved correctly.

Of course there are tactical exercise positions out there, but I don't know any that are already sorted by motif or difficulty. This is a site with 10,000 tactical positions (surely mined by a computer):

http://www.wtharvey.com


Must one say "queen check" before capturing a queen?

The official FIDE laws of chess do not know about a queen check. Announcing a  "queen check“ might even be considered a case of "to distract or annoy the opponent“ (11.5). Even announcing a "king check“ is not recommended.
That’s for tournament chess. In informal games, it is not unusual in some groups to announce a check and a "queen check“ (by "gardez“, French for "keep attention“). Even there it is not a rule, but a courtesy. Not announcing a check or gardez is considered impolite, but you may take the queen anyway.


Why didn't the White queen take the Black rook here?

I think it's just a blunder from White; the white queen is not at risk of being trapped, nor is it needed for defense. Qxa8 would have definitely been the best move.

Note that the player's ratings aren't that high (no idea how they compare to FIDE ratings though).


1.Nh4 is best, preparing to decisively take on g6. Black can't do much to brace for this move. For example, 1...Rd8 2.Nxg6 fxg6? 3.Qxg6+ Ng7 (3...Kf8 4.Bh6+ leads to mate) 4.Bh6 e6 5.Qh7+ Kf8 6.Qh8+ Ke7 7.Qxg7+ Ke8 8.Bg6+ Qf7 9.Qxf7#.
It would be better if Black played ...f5 either on the first or second move, but this clearly isn't challenging since then your knight just takes on g6 for free, and White's attack is crashing through.


I was thinking if you were the author of https://decodechess.com, and posted here for self-promotion. "decode" isn't a common terminology here. What you're asking match exactly to the name of the site.

Ok. Please take a look at the site.
I personally don't use it as I found the analysis too simple/too naive. Maybe you'd think otherwise.


Is there a trick to help kids know which direction pawns are going?

At 5 years old a child's brain is still very immature. The good news is that it is also developing very fast. The easiest and most effective solution is just to wait. Within a year or two the problem will have solved itself as your child's brain develops enough to satisfy your expectations.


Is there an aggresive opening for black if white does not accept the Traxler's counterattack?

The Traxler counter-attack starts if White plays Ng5 in this position.
[FEN "r1bqkb1r/pppp1ppp/2n2n2/4p3/2B1P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4"]

1. Ng5

Without Ng5, there is no Traxler counter-attack.
I think that 1.e4 e5 is not the best way of preparing an attacking and aggressive battle with Black. That is why I play 1.e4 c5 and go for the Sicilian Najdorf variation. I think that asymmetry is a good way of seeking imbalance and dynamic play. While symmetry is more likely to lead to less dynamic positions. Thus, 1.e4 c5 and 1.d4 f5 are approaches to seek more dynamic play, in most extreme cases, by castling on opposite sides and launching pawn storms. Your opening choice leaves White with the option of accepting with Ng5 or declining with a different move. If you want to ensure dynamic play, I think it is better to look for opening systems where you have more control of where the game goes so to speak. I hope this helps.


Instructive games with a white h-pawn push in the Smith-Morra gambit?

I checked my main games database and my book on the Smith-Morra, "The Modern Morra Gambit" by FM Hannes Langrock. I could find no examples of high-level players successfully employing this strategy to launch a kingside attack. The Smith-Morra focuses very strongly on quick central control and development, so it makes good sense to me that white's play will almost always be focused on the centre rather than along the h-file.

The one system within the Smith-Morra where I found a couple of examples of white successfully playing h4-h5 was in the Nge7-system. In this system, black plays Nge7 and Ng6, with the aim of using the knight to add extra control over the e5-square. In these cases, h4-h5 was usually played not with the aim of a kingside attack, but with a view to chase away the strongly placed black knight and regain control over e5. I did find one interesting example in the aforementioned book of white using this to instigate an attack, though it revolved more around using the e5-pawn as a central wedge rather than an attack on the h-file. It was given as D.Cantell Martinez - O.Martinez Rodriguez, Asturias 2001, though I don't know how much value to attribute to it as couldn't find it in my main database nor on chessgames.com, and I couldn't find the players for sure on the Fide ratings website (I found two possible O.Martinez Rodriguez, rated  about 1800 and 1900). In any case, it was given in the book as:

  [FEN ""]
  [White "Martinez"]
  [Black "Rodriguez"]

  1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 e6 5.Nf3 Nc6 6.Bc4 Bc5 7.O-O a6 8.Bf4 b5 9.Bb3 Nge7 10.e5 Ng6 11.Bg3 O-O 12.h4 Qc7 13.Re1 Rd8 14.h5 Nf8 15.Ne4 Be7 16. Nf6+ Kh8 17. Ng5 g6 18.Nxf7+ Kg7 19.Qf3 Bb7 20.h6+ 1-0

Overall, it seems to be a very uncommon theme in this opening.


How to balance the game for uneven players

(Disclaimer: this is my first post on this network, and in all honesty both you and your wife could probably beat me at a game. But I do have years of experience of finding handicaps to make chess games more even and enjoyable.)

Time advantage: this probably depends on your situation. Some people are great at untimed and terrible at rapid, but tinkering about with time differences until you find a healthy compromise has the positive of being very flexible as it can be fine-tuned very precisely. I find the pressure is greatest on the stronger player when you use a time per move system rather than a time per game - and the weaker player can play untimed.
Further piece advantages: I've never needed to go much beyond a queen handicap, but I imagine two rooks or a queen and minor piece would be the next step.
Blindfold chess: you could try playing without being able to look at the board (while your wife can), if you've ever done blindfold chess before or feel you have enough experience/memory to try. A somewhat easier version might be to only allow you to look at the board while it's your turn, which only makes sense if you're using time controls.
Help her to improve: it may be that the two of you playing against each other doesn't make sense with such a large difference in skill. How about you play practice matches where you offer her tips and guidance, allow her to undo any blunders and teach her until she is at a similar skill level?


Is it technically a checkmate if the king is not in check, but all moves will result in check?

Putting your king in check is not a legal move as you've realized.
Of course, if Black has any OTHER legal moves he can and should play one of them!
If a side TO MOVE does not have ANY legal moves, that would be a stalemate, not a checkmate (which is delivered only by the side making the check)


What is a DGT 2010 Limited Edition chess clock worth?

These are still very common, so not worth a lot. Considering that the more recent ["DGT 3000 Limited Edition" clock can be bought for $59.93][1], at least it held its value, but no more. Don't be fooled by "Limited Edition"...it does not equate to "rare".

P.S. Sorry, I did not pickup on the difference...they both looked red to me, but I see it now. Frankly, I still do not think it is going to make it valuable unless you wait many years, but you can do a couple of things to find out what it is really worth now:

Put it up for sale on eBay and start high with the price, but if you do, only use a "Buy It Now". If you put it up for bid, you will definitely get a lot less.
Set up an eBay search that sends you an email every time there is a new listing. Eventually, someone is sure to be selling one, and you will get an idea of what it is worth when it sells.


In Fischer-Petrosian 1971 game 7, why did Fischer give up his good knight for a bad bishop?

This is a very famous position. Well, here are some reasons, and there are quite a few:

Since this was a Candidate’s Match to qualify to play Spassky, it comes down to exact calculation above all. Fischer calculated that it was good, and his judgement bore out since the game only lasted another 12 moves. Here are some things that probably contributed to this judgement.
It was clear that black had to take with the Ra7 so as not to lose d5, and after that, neither black rook remains well placed since the Ra8 cannot leave the Pa6 undefended, and either the Rd7 or the Nf6 is stuck defending d5. D5 also limits the scope of the Rd7, in particular.
It also leaves the Pa6 particularly weak since the Bd7 might have been able to defend it. GM Mikhail Suba is famous for saying "Bad bishops defend good pawns!" In addition, when you look at the minor pieces that are left, the Bd3 versus the Nf6 is clearly in favor of the B and its nice scope. It is of note that if black tries to liquidate the Pa6 weakness with a5, white can just push, creating a dangerous passer.
Lastly, and most importantly in this position, the white Ra1 immediately takes the only useful file, the c-file, with an immediate threat of Rc6, thus black played Rd6 stopping it, which allowed white to take the 7th rank.
In all fairness, the computer finds both 22.a4 and 22.Rc1 stronger by about half a pawn, but Fischer’s method is clear, and very straightforward.


Does one need to know all popular openings if they wants to be a top-level player?

It would be difficult.
So you go into your first top-level tournament and get Black in the first round. No problem, you'll just play your Caro-Kann. Play goes 1. e4 c6 2. c4 d5 3. cxd5 cxd5 4. exd5 Qxd5 5. d4. You've just transposed into a line of the Alapin Variation of the Sicilian.
In the second round you're White and play 1.c4. Your opponent plays 1...e5 to go into a reversed Sicilian, and suddenly you're really wishing you knew something about that opening.


What should I do when I have no ideas and no strategies?

This is very hard to answer since the question is very broad, but in the opening, always ask yourself "what piece haven't I moved out yet?" If you move pieces twice or three times in the opening, and I am developing each one after only one move, soon you will be fighting with only two or three pieces against me with 5 or 6. You will not win that way.

Other than that, ask yourself what pieces of yours are not defended, and make sure they are safe; and conversely, look at what your opponent has that is undefended, and see if you can take advantage of that. Not losing pieces is the biggest problem for weak players.


Moving pawns which are defending the king

There are no advantages.

The really big disadvantage is that after:
1. f4 BxN
2. bxB QxQ
3. RxQ Bxe4
you are completely lost, a clear piece down with no compensation whereas after
1. Qh5+ Kf8
2. QxB
you would have been a pawn up with a much better position.


With this particular continuation

xf6 ...Qe5+
Be2 ...Qxg5
0-0

should provide white with good play, I've compared some databases which generally favor white in this position. Instead of B5 many players including grandmasters favor an immediate 7...Qb6.

I suggest looking into some databases(chessgames.com has a fair amount of games as does chess.com however chess.com requires membership for proper database analysis) to see possible continuations since I do not play this particular variation. I can only assume computer analysis has somewhat dealt with the b5 variation since it does not provide black with much development and leaves space open for white's knights.


Using the Stockfish move generator in a home chess engine

For the fastest move generation I suggest the below code.

https://github.com/Mk-Chan/WyldChess/blob/master/src/magicmoves.c

It’s not the Stockfish source code, but I was able to use it for my own hobby engine and I can tell you that it’s very fast. If you have a lot of trouble I can write a post about how I did it.


After you blunder, it's incredibly common to blunder a second time over the next few moves.  The most important thing you can do is to avoid this second blunder.

In order to do that, you should take a few deep breaths and even get up and walk around.  Although it's nice if your opponent doesn't know that you blundered (i.e. your "blunder" could be part of a deep plan so far as your opponent knows...), it's far more important to remain calm and stay focused on the game.

After this initial "cool down", now it's time to re-evaluate the game.  First, are you hopelessly lost at this point, or is the position still unclear?  Perhaps you gave away your winning advantage, but you are still equal.  If you are not lost, it is crucial that you maintain your focus and play accurately - you still have a chance to win or draw.

On the other hand, if your blunder was so egregious that your game is hopeless now, it's time to start thinking about "tricks".  For example, if you hung a pawn or two for nothing, it's time to attack with abandon.  If you can checkmate your opponent, it doesn't matter that you're losing an endgame.  If you hung an entire piece, keep all other material on the board and maintain tension in the position.  The goal here is to try to win tactically (win material back from your opponent or go for an attack).  Another common theme is to introduce time pressure into the game.  Either play tricky moves and force your opponent to get low on time, or let your own clock tick down to a minute or two and pray that your opponent blunders in your time pressure.

As a final note, when you are behind in a chess game, it's almost always good to trade pawns, but not pieces.  The rationale is that in an endgame, each pawn is a potential queen for your opponent, while on the other hand, pawnless endgames with an extra piece are notoriously difficult to convert to a win.


In short, because DeepMind has TPUs. Lots and lots of TPUs.

By far, the most time-consuming part of the training process is generating self-play games. DeepMind used 5000 TPUs to generate self-play games, which is a lot of processing power. Meanwhile, Lc0 crowdsources processing power from volunteer clients, which is much slower.

From the DeepMind paper published December 2017 (emphasis mine):

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

To achieve the level of performance that AlphaZero got against the (sub-optimally tuned) Stockfish version 8, the training run took about 9 hours and 44 million self-play games for chess:

Meanwhile, the Lc0 project got started sometime in January 2018, and by April 2018, they'd only generated 8.2 million out of the needed 44 million games. I believe they were generating about 200k games per day at the time.

They also came across a lot of bugs in the process and were figuring out a lot of things as they went, so when the first training run plateaued, the best net was not as good as AlphaZero. Since then, the Lc0 project has actually restarted the training run multiple times:

old main: The original 192x15 "main" run, using the original lczero.exe engine. It ended in August 2018, with the last net being ID595. (These nets don't seem to be listed anymore though? The early IDs at the bottom of the net list seem to be these test nets.)
test10: The original 256x20 test run. This was a separate pipeline using a completely rewritten lc0.exe engine that was much faster at generating self-play games. Net numbering for this run started with ID10000 on June 27, 2018, and ended with ID11262 on August 30, 2018.
test20: A run with various changes, starting with ID20001 on August 30, 2018 and ending with ID22201 on November 16, 2018.
test30: A run testing various new ideas, starting with ID30001 on September 9, 2018. As of January 14, 2019, the best net was ID32598.
test40: The December 6, 2018 AlphaZero paper revealed a lot of differences between what DeepMind did and what Lc0 did, and it looks like a new test run started with ID40001 on January 8, 2019. As of January 14, 2019, the best net was ID40202.

To get a sense of how well Lc0 is doing compared to AlphaZero, it's more useful to look at the Elo with respect to total number of games generated, not time elapsed. Here's what the graph looks like for the entire Lc0 project as of January 14, 2019 (note that this is self-play Elo, which is inflated compared to actual Elo):

As you can see, they've reset the training run many times. There were also a number of bootstrap mini-resets during the original main run to fix some critical bugs, and there was also a temporary test35 to test the newly revealed configuration settings from the December 2018 AlphaGo paper. Yep, this isn't confusing at all! (/s)

There are lots of calculations and graphs in this spreadsheet here that compares lc0's performance with AlphaZero. For example, here's the graph from the first old main run (under the "Graphs" tab):

From that link, an explanation of what "Leela Max" is:

  "Leela Max" is Leela's theoretical maximum performance when given hardware and/or time to the point of absolute diminished returns. It may be more comparable to AlphaZero, as AlphaZero operated on 4.8 million nodes per move, whereas a conventional setup only gets a small fraction of that.

These days, the self-play generation speed is much faster than it was at the beginning. As of January 14, 2019, it looks like the project is generating about 1.5 million games per day. But at this speed, it'll still take a month to achieve what DeepMind achieved in 9 hours. More like double the time, really, if the training games are being diverted towards two separate runs.


At what level would a player be able to correctly analyze how ...a5 is superior to ...Bc5 if LiChess puzzle 94536 arose in a tournament?

Some things make it difficult....

several motifs are involved: two clearances, trapped piece, discovered attack (and you have to see all them in order to understand the problem)
the particular form of these motifs is non-standard (meaning there are  more usual patterns for any of these motifs):

moving the bishop to f1 to clear the d pawn, is rare;
trapping the bishop with just one pawn (more common is a theme with a white pawn on b4 and a black pawn on c7);
clearing the diagonal by playing c5 (this is essential for the discovered check);
discovered check with a pawn is not very common either

Moving one of the double-attacked pieces is not what one might come up first, because it often loses a tempo. One might be tempted to have an attitude like: anyway I'll lose one of the two pieces, perhaps I could  make a useful move with one of the other pieces.
One would have to calculate this defensive tactics from the black, i.e. from the attacker side which is for many people more tricky as (at least lower rated) players tend to do a lot more tactics that ask for winning/mating, etc than doing defensive themes.
In a tournament game (unlike in a composed study) you never know whether there is one good move or several equal (or almost equal) moves.

Some things in favour of finding the correct move:

Since e4 has the potential to win a piece and therefore the game, the black player in a tournament game would want to make extra sure and invest plenty of time to check any defensive options.
The move a5 once and for all makes sure that the bishop on b4 is save, because it cannot be attacked by white pawns on that square and at most one would lose a pawn on any trade on b4 (after having checked that the pin along the a-file is not a problem).

Overall I think that because of the multiple non-standard motifs involved it is a very difficult problem in a tournament game. If you want a number, my estimate would be around 2200 ELO, but this might be more about how careful the player is than about what his rating is.

Given enough time (10+ min or so), I believe that a lower rated player of around 1800 should be able to find the solution if told that there is a unique solution.


App that identifies moves as Excellent/Good/Mistakes/Blunders

I would suggest starting at lichess.org. It has tools that let you (1) analyze a game that you play on the site or (2) import a game and analyze it.

The lichess.org analysis includes inaccuracies, mistakes, and blunders. It does not have excellent or brilliancy (! or !!) markers, but they provide a rationale for why they don't use those. You can decide whether their explanation suffices for your purposes. They use a centipawns lost or gained graph that seems to be a good indicator of the game state. And they often suggest better moves with the corresponding alternate lines.

They have an Android app at https://en.lichess.org/mobile that you can try out to see if it meets your needs. You can also try out their web site on a mobile device to see how that works, too.

Finally, what I like about lichess.org is that they seem to have a great interest in having a clean, stylish piece and game user interface and they also seem to be actively developing, so if you have suggestions they may take a listen.

EDIT: Somehow I neglected to mention earlier that the site is free and the code is open source. Both are great if you want to save some money while learning chess and even possibly get interested in seeing how the site code works.


Are there any attempts at writing Stockfish MCTS?

This is difficult to answer definitively as there is obviously no way to say that there isn't someone somewhere working on an MCTS version of Stockfish. However, as of the time of writing, there exists no official attempt to create an MCTS version of Stockfish.

While some forks of Stockfish, such as ShashChess and SugaR have MCTS-like modes, they differ from what you are looking for:

One of these modes applies a simple neural network to determine R in Late Move Reductions in Stockfish's alpha-beta search.
The alternative collects MCTS-like information for each root move by collecting the evaluation of every node visited in a standard alpha-beta search. This is not really MCTS as it only collects additional statistics on the same alpha-beta search function.

Komodo MCTS, which does use its own handcrafted evaluation function and a full-fledged MCTS search, is only competitive with the standard version due to the fact that its implementation of MCTS applies alpha-beta rollouts: i.e. the alpha-beta search used in standard Komodo is used to determine the expected win % for leaf nodes, and also as the policy to determine which nodes should be preferentially expanded.

The exact methods by which Komodo MCTS converts its alpha-beta score to an expected win probability, as well as the details in how alpha-beta searches are used to determine which node MCTS should expand, are all proprietary. As such, it's unlikely that implementing MCTS in Stockfish is anything close to trivial.


How should I configure Stockfish if I want it to play as a 2800 ELO player without the UCI_LimitStrength value?

So couple of issues off the cuff;
Do you have a particular version in mind?
Chess engines don't exactly have "ELOs". Chess engines are about calculation speed, calculation depth. They guestimate (at best) to determine a theoretical strength then measure against  other engines.
Stockfish 9 with 4 Cores is ~ 3200 "ELO"
Stockfish 12 similar rig I would argue is around that 3400-3600 "ELO" Mark.
The Reality; Playing solely against engines, at the highest level is ill advised for any development and engines are best used for position analysis (if that).


The chess.com vs computer games celebrity category

I have spent some time playing the lower-rated bots, and can confirm they tend to have different "personalities". I'm not a strong enough player to explain exactly how they are different. However I have observed that some are more aggressive, and tend to gravitate towards particular openings depending on the color.
I know that Hikaru recently did a series of videos on youtube where he played against bots. When I saw the new bots, I had a feeling that it was for the purpose you describe.


What defines a forcing move with major/minor pieces?

Forcing move is a term for a move that leaves an opponent with a few options, only one of which does not lead to an immediate loss. This could refer to a variety of circumstances. For example, you might see a mate in 3 puzzle in which the first move is a forcing move because the opponent's only other legal move falls to a mate in 1. The term can also be used in opening theory, like in Ruy Lopez situations where black's b5 forces Bb3, or the loss of the bishop. The term may also be used for situations like 1.e4 c5 2. Nf3 Nc6 3. Bb5 a6, after which white is left with one good option, 4. Bxc6, and several bad options, such as 4. Ba4, which just loses the bishop, 4. Bc4, which allows black queenside expansion while losing another move, 4. Bd3, which blocks the d-pawn, 4. Be2 which is probably the best alternative but yields the b5 square without a fight, and 4. Bf1, which severely hampers development. While white has other options, they are strategically weak, and it could be said that black's a6 is a forcing move. So there is a wide spectrum between checkmate situations and less dramatic situations in which there is only one reasonable move.


That opening repertoire looks good to me. However, I must warn you about over-focusing on opening theory at your rating level.

Right now I am going through a phase where I am focusing on other areas besides opening theory.  Some of the old masters, such as Lasker, didn't even bother with it.  Although I'm not sure if he would get away with that today.  I do think that a lot of lower-rated players focus too much on opening theory.  In most of your games, opponents aren't going to be playing the books moves, so it may actually be a waste of time to learn a bunch of opening theory. Instead it may be more beneficial to REALLY learn a solid set of chess principles, and even more importantly patterns.


How should a beginner improve gameplay speed?

You should only be spending time on a couple of candidate moves. This might shorten the thinking time if you rapidly dismiss moves that bring nothing to your position.

IM Jeremy Silman says in his book The Amateur's Mind that each move should have at least two purposes (amongst attacking, defending, gaining space, developing, gaining initiative, etc.).

You can also limit the lines you calculate to one and a half move : your move, the opponent's most likely reply, and then your next move.

I hope this helps.


Opening the e-file in King's Indian Defense?

I am not sure if you are leaving something out, but what he means is that depending on what white does, assuming it does not lose, black may play e6xd5 and then Re8 to get play either against e4 if white recaptures with c4xd5, or possibly other play down the open file should white respond to e6xd5 with e4xd5.

I also think you may be misreading the notation since there is not going to be exd6 or exf6.


This would be checkmate, because the king is in check and has no valid move to escape. But it's impossible to get into this position if you follow normal chess rules. The most you can do is a double-check (using a discovered attack), but your position shows a triple-check.

The stalemate rule is only applicable when the king is not in check, so it doesn't apply here.


In this case, the pawn on d4 is not just a target.  It's also restricting white's bishop on c3.  For that reason, it's very important that black not allow white to sacrifice this pawn by playing d4-d5 when white would have very good chances to hold.

Black would like to trade off light square bishops and then put a rook on d5.  The immediate 1...Bxe4 2.Qxe4 Rd5 fails tactically because white can play 3.f5! with decent counterplay on the kingside.  Additionally, at least one pair of major pieces will be traded off after white plays f5, and generally speaking the side with the isolated pawn or backwards pawn wants to trade off major pieces.

After 1...Rd5!, white cannot take on d5 because the Be4 is pinned to the white queen.  Black will play 2...Bxe4 next move and then a move like g6 in order to stop white's f5 advance.  Black will be much better - nearly winning - because black can slowly bring the dark square bishop around to f6 or g7 where it will attack the d4 pawn.  Black will also double rooks on the d file.  White, in the meantime, has no constructive plans that don't create new weaknesses.


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


When Lichess analyzes a game, how deep does it analysis?

It tells you at the top right.

The first number (19) tells you the depth it has analyzed to (19 ply = 9.5 moves). Note that because of engine heuristics, it doesn't exhaustively search for every single move 9.5 deep. The second number (23) tells you the max depth to which the engine is searching for. After the bar fills up, there is an optional feature that lets you increase the depth beyond 23 if you want to explore a specific position further.


I had an extra pawn and was closer to my pawns then White

It seems you simply overestimated these two factors.

An extra pawn alone is not a decisive advantage, it matters a lot where it is located. If the f7 pawn was on a7, you'd win.

The kings are actually positioned to your disadvantage, White's is nicely centralized and yours is stuck in the corner. If the White king was on g2 and yours on e4, you'd win.

But most of all, chess endgames are concrete. If you shift the whole position one file to the left, the engine does indeed see black winning!

What makes your position a draw is the unfortunate pawn formation: Your own doubled pawns trap your own king in the corner, while White's are flexible enough to shut the position from the front. And as said, his king is well positioned, it can either block the escape of yours via d8 or assist his own pawns in preventing the frontal breakthrough.


Which FIDE rule forbids pressing the clock before taking captured pieces off the board?

It sounds like you were breaking the rules on several fronts.

According to the FIDE Laws of Chess:

  6.2.3 A player must press his clock with the same hand with which he made his move. It is forbidden for a player to keep his finger on the
  clock or to ‘hover’ over it.

You would probably be punished under the illegal move rules:

  7.5.2 If the player has moved a pawn to the furthest distant rank, pressed the clock, but not replaced the pawn with a new piece, the
  move is illegal. The pawn shall be replaced by a queen of the same
  colour as the pawn.

  7.5.3 If the player presses the clock without making a move, it shall be considered and penalized as if an illegal move.

  7.5.4 If a player uses two hands to make a single move (for example in case of castling, capturing or promotion) and pressed the clock, it
  shall be considered and penalized as if an illegal move.

  7.5.5 After the action taken under Article 7.5.1, 7.5.2, 7.5.3 or 7.5.4 for the first completed illegal move by a player, the arbiter shall give two minutes extra time to his opponent; for the second
  completed illegal move by the same player the arbiter shall declare
  the game lost by this player. However, the game is drawn if the
  position is such that the opponent cannot checkmate the player’s king
  by any possible series of legal moves.

It sounds like you were either moving with one hand and pressing the clock - 6.2.3 or using two hands to make the move - 7.5.4


The average blitz rating on chess.com is 1090
The average blitz rating on lichess is around 1600
So that looks just about right. chess.com is closer to Fide.


What is it about Soviet born players that makes them winners in the brutal 128-player knockout format of the World Cup?

Most top participants were ex-USSR. Almost all of the World Cups were held in ex-USSR countries. And the rest is coincedence.

Especially in earlier years, most of the top participants were born in the USSR.

E.g. in 2005, the top-25 by rating of the participants was Ivanchuk, Bacrot, Aronian, Grischuk, Gelfand, Shirov, Akopian, Radjabov, Ponomariov, Tiviakov, Sokolov, Dreev, Kamsky, Bologan, Lautier, Bruzon, Bareev, Mamedyarov, Vallejo Pons, Smirin, Harikrishna, Malakhov, Sakaev, Volokitin, Moiseenko.

Only 6 in 25 (Bacrot, Sokolov, Lautier, Bruzon, Vallejo Pons, Harikrishna) were not born in the USSR. And only 1 in the top-10! And that tournament had Kasparov, Kramnik, Anand, Topalov, Svidler and Morozevich (4 out of 6 USSR) missing because of world championship situations.

In later years the number of non-USSR players grew slowly, but in 2011 the first non-USSR player on the list was #12, Zoltan Almasi.

2015 was the first year with only 4 USSR players in the top-10, but 11 in the top-20 (#11 Karjakin won).

It's only in the last few years that it's a bit against the odds that a USSR player won it.

There are of course top non-USSR players: Carlsen, Anand and Topalov were consistently in the top most of this period. But as the World Cup was mostly a qualification event for the Candidates and they qualified otherwise (or were World Champion), they played in very few World Cups.

Apart from 2013, all World Cups were held in USSR countries

Of which three times in Khanty-Mansiysk, Siberia, sometimes in november/december. I think Russian speakers have a psychological advantage in Siberia, they feel more at home because they can at least understand the people.

Coincedence

Taking the facts above, this is easily within the realm of coincedence. I wouldn't bet on a ex-USSR winner next time purely based on the results so far.


Is it possible for an engine to be stronger at short time controls, and weaker at long time controls?

Why not? I don't have an example here, but cache implementation could be a major factor.

A cache algorithm that doesn't scale well with time will not perform well on a long time control. No matter how much memory you have, at longer control it will surely be filled up very easily and very quickly.


In the Queen's Gambit Declined, after 1. d4 d5 2. c4 e6, what is the difference between playing 3. Nc3 and 3. Nf3?

With the 3.Nf3 move order your opponent can obtain a favorable position, almost entirely destroying your advantage.

Here is a small example:

[Title "Black dodges the Exchange variation"]
[fen ""]

1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.Nc3 Be7 5.cxd5 ( 5.Bg5 O-O 6.cxd5 Nxd5! ) 5...exd5 6.Bg5 c6 7.Qc2 ( 7.e3 Bf5! ) 7...g6! 8.e4!? ( 8.e3 Bf5! ) 8...dxe4 ( 8...Nxe4? 10.Bxe7! ) 9.Bxf6 Bxf6 10.Qxe4 Kf8!? 11.Bc4 Kg7 12.O-O Re8 13.Qf4 Be6 14.Bxe6 Rxe6 15.Rfe1 Qd6! 16.Qxd6 Rxd6 17.Re8 Rd8 18.Rxd8 Bxd8 19.Re1 Nd7=

With the 3.Nc3 move order, you are on the correct path towards the Exchange variation, but Black has a choice to sharpen the game. He could play 3...c6 offering you the Marshall attack, and even if you decline the offer and try to steer into the Exchange line, he could play ...dxc4 ( immediately or in the next move ) sharpening the game. Do not forget that Black may decide to play ...Bb4 entering the Nimzo-Indian defense which leads to open, dynamic play in most cases.

Be aware that you can not dodge sharp battles with the Nc3 move order, but it is the only correct path to a solid Exchange variation for White.

  Firstly, I am an extremely positional player, I don't like sharp and crazy games full of tactics. I would prefer the move which in average leads to the most solid, positional, slow, closed, strategic and quiet positions. I don't know which move that would be.

You can't achieve what you ask for 100%, since Black has a say too. The best you can achieve is "healthy compromise" -> you can get a positional battle without crazy tactical sparks, but the game will still be dynamic and sharp.

  Secondly, as White, I always develop my King's Knight to f3, not to e2. This is a plus for 3. Nf3, since if I'm going to develop it there anyway I might as well do it right away on the third move.

With the 3.Nc3 move order you can just play Nf3 anytime you want. The point is that you have a choice, that is all...

  Thirdly, I like playing (as White) the Exchange Variation (of the Queen's Gambit Declined) very much. Not with Ne2, f3, e4. I play it with Nf3 and a minority attack on the Queenside. This is a plus for 3. Nc3, since it's impossible to get a good position in the Exchange Variation if you begin with 3. Nf3 which loses a tempo.

Again, the only correct path towards the solid Exchange variation is with 3.Nc3 move order. You can choose between Ne2 and Nf3, it is a matter of taste, but know that Ne2 is a critical line for Black in the Exchange variation.

  And lastly, against the Slav, after 1. d4 d5 2. c4 c6, I prefer to play 3. Nf3 over 3. Nc3, because I heard that 3. Nf3 was much more solid and quiet, and that 3. Nc3 can lead to very sharp positions. For example: 3... e5!? looks sharp and crazy, it's possible after 3. Nc3 but not after 3. Nf3. This is maybe a plus for 3. Nf3, since if I already play 3. Nf3 against 2... c6 maybe this means I should also play it against 2... e6.

Against the Slav move order, you have time before playing 3.Nc3 as he can't respond with a fast ...Bf5 so I would make an exception there and play 3.Nf3 to rule out any sharp play.

Still, I would go for other quiet lines against the Slav, instead of trying to enter the Exchange variation of the QGD. You should consult opening manual to see if there is a safe transposition, otherwise you might get tricked into an inferior position. This should not be a problem as far as I remember, since there are lots of quiet lines in the Slav for White that suit your style.

SUMMARY:

Against QGD play Nc3 and enter your favorite line, but against the Slav stop early sharp lines with Nf3, and do not attempt to transpose into the Exchange variation of the QGD. Instead, head for the lines with Qc2 or similar, these will suit your style.

If you have further questions leave a comment. Good luck and best regards.


Under FIDE rules, the performance rating is calculated by taking the average of your opponent's ratings, and then adding a factor from a table based on performance.  Let's say you played 5 games, against people rated 1380, 1390, 1400, 1430, and 1900, and had 3 wins and 2 losses.  You scored 60%, or 0.6.  According to the table in section 1.49 of this document, in this case your performance rating would be adjusted upward by 72 points.  The average of your opponent's ratings was 1500, so your performance rating would be calculated as 1572.

The downside to this method is that the ratings averaging can be skewed by one opponent with a very high or low rating.  If you changed the 1900 opponent in the above example to a 2900 opponent and decreased the wins to 2, the performance rating would increase to 1628, even though you performed worse.  If you instead changed the 1900 opponent to a 1000 opponent and increased the wins to 4, the performance rating would go down to 1560, even though you performed better.

The USCF ratings estimator calculates performance rating by calculating how a player at a particular rating would be expected to do against the given opponents, and comparing it to the actual result.  In the example above, a player rated 1563 would be expected to score 3 based on those opponents, so that's the performance rating.

The downside to this method is that there's not just a simple formula you can figure out in a few seconds.  The upside is that it's less prone to being skewed by one very high or low rated opponent.


Caro-Kann, Smyslov variation : Can Black punish early 5.c4 in this position?

5.c4 is bad in the Smyslov variation because black can equalize instantly with 5...e5! 6. dxe5 Qa5+ and 7...Qxe5.  Black is not better though, it merely gives black an easy game with the queens off.

For the complete line:

[Fen ""]
[Title "Smyslov Variation"]

1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Nd7 5. c4 e5 6. dxe5 Qa5+ 7. Bd2 Qxe5 8.
Qe2 Nc5 9. Nxc5 Qxe2+ 10. Nxe2 Bxc5 *

In the line you give with 5...e6, white retains a comfortable advantage.  White can play the standard plan of Nf3 and Bd3 and either try to keep the knights on the board with Nc3 after black plays Ngf6 or swap a pair of knights with a good position based on black's bad light square bishop.

Some example lines that give white an edge:

[Fen ""]
[Title "Marshall Gambit"]

1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Nd7 5. c4 e6 6. Nf3 Ngf6 7. Bd3 (7. Nxf6+
Nxf6 8. Bd3) (7. Nc3 c5 8. Be2 cxd4 9. Nxd4 Bb4) 7... Nxe4 8. Bxe4 Nf6 9. Bd3
Bb4+ 10. Bd2 *


Is it theoretically possible for Carlsen to reach Elo 3000?

The average Elo rating of the e.g. top 10 players in the world is rising every year. I think that the relative distance between the number one rated player and the other 9 players in the top 10 becomes relevant in this context. This distance can be estimated by subtracting the average of the ratings of the 9 players (ranked 2-10 in the world) from the rating of the top player (today, Carlsen) and dividing this by the rating of the top player.

Increasing this distance is difficult for the top rated player, because every new game played by the top player has a certain amount of risk and uncertainty. I think that Carlsen will have a hard time reaching an Elo rating of 3000 exclusively by increasing the distance to the players ranked 2-10. Yet, if the relative distance stays the same of the following years and the average rating of the top 10 continues to increase, then it is definitely possible for Carlsen to reach Elo 3000. The second ranked player at that moment would probably have around Elo 2950.


How to play against the Grob attack 1.g4

I play the grob a lot, and i don't ever mind if people go into those main lines. That is actually what anyone playing the grob wants.

The easiest play for black is going with 1.e5 and a quick Ne7, Ng6, Nh4! This can't be prevented, the knight is hard to remove from h4 due to the weakness from 1.g4 and it hits the white bishop on g2 which white doesn't want to trade but it's either that or the ridiculous Bf1. That simple plan makes white look silly and gives an easy nice position for black from the opening.


Lichess vs Chess.com ELO system and player strength

Lichess recently added a concise explanation to its site:
Chess rating systems
Important points:

Chess.com uses the Glicko-1 algorithm with an initial rating of 1200.
Lichess uses the Glicko-2 algorithm with an initial rating of 1500.
Neither of them uses the Elo algorithm (not ELO - it's not an abbreviation).
Furthermore, it doesn't make sense to compare the ratings even if both sites used the same system, as they have different player pools.

If we are just talking of abstracted playing strength, the assertion that one site is "easier" than another still doesn't make sense. Elo and Glicko systems all have in common that if you get matched with players with the same rating as you have, they will on average have the same strength. So even if one pool is better overall, you as an individual wouldn't notice as you would be matched to comparably skilled players on both sites.
Unless your friend is a Super GM, of course.


Why does AlphaZero implement time steps in its input layers?

I don't know how to play Go at all, but the paper wrote:

History features Xt, Yt are necessary, because Go is not fully
observable solely from the current stones, as repetitions are
forbidden

For chess, I'm unable find any mention about it in the paper other than:

Unless otherwise specified, the training and search algorithm and
parameters are identical to AlphaGo Zero (29).

The training process was identical, but the sentence made no mention about the input features.
If you study the papers more carefully, the input features for Go is:
st = [Xt, Yt, Xt−1, Yt−1,..., Xt−7, Yt−7, C]

It's a representation only for Go, not chess. The input features for chess outlined in the paper covers 50-move rules and repetitions already, so there isn't any need for time steps in the input layer.
Google didn't use timesteps for chess, but only for Go.

Also, the architecture that I'm trying to build is not a Reinforcement
Learning model, but rather a supervised learning one based on the FICS
game database of players with high ELO. Basically, I will train 2
separate models, one for white and one for black. Data for the white
NN is taken from games where white wins, black NN takes black wins,
drawn games are used for both, so that white moves in white winning
games are considered "good", and vice versa. Is this a reasonable
approach?

Supervised learning is ok. It doesn't make sense to me for an ensemble of two models here. Why not just model it as a probability from 0 to 1?
EDIT:
You actually do need the entire game history in chess, for 50-moves and repetitions.


After the exchange of white squared bishops black will play e6 cementing the center, leaving all his pawns on white squares. The white squared bishop is Black's bad piece in these structures and conversely it is white's best piece. The exchange very much favours black.

With black pawns on d5 and f5 white isn't going to be opening the center any time soon so the black king is safe in the center. Black has at least equalised.


Would a piece that moved like a king – but could be captured (and could be moved en prise) – be considered a major or a minor piece?

This piece is widely used in different fairy chess variants. It appears under several names, including Commoner, Guard and Man / Mann.

While the table in the Wikipedia article also linked to in @Allure's answer states it's worth about four points, the article itself limits that value to the endgame:

  In the endgame, where there is usually little danger of checkmate, the fighting value of the king is about four points (Lasker 1934:73). In the endgame, a king is more powerful than a minor piece but less powerful than a rook. Julian Hodgson also puts its value at four points (Aagaard 2004:12).

On the other hand, the Wikipedia article about the fairy chess piece says

  A man is approximately equal in strength and value to a knight, generally.

That would make it a minor piece. It might depend on the board size (it's less effective on large boards, and worth much more on small boards) or the other pieces available to the players.

  it seems like the major determinant of whether a piece is a major piece or a minor piece is whether a king and one of that piece can force checkmate on a lone king

That's close to the definition I've heard: a major piece is one which can cut off the enemy king from one side of the board. Rooks and queens can do this, but this non-royal king cannot.

On the other hand, there is a basic situation where this piece is even stronger than a rook. King + rook lose against king + queen, but king + commoner is a rather simple draw.


6. dxc5 is just a good move, and you cannot really hope to refute it. It was given an exclamation mark in Grandmaster Reportoire 10 by Ntirlis and Aagard, and their main line starts as in your diagram.

Moves such as dxc5 were underestimated by older theory because they were thought to give the initiative to black. Nowadays with computers we can analyse more concretely and see if blacks initiative is something to be afraid of or not. In the case of 6. dxc5, the analysis seems to suggest that white ends up with a small advantage.


Ruy Lopez 3...a6 & 6...Bc5 setup - a4 vs c3+d4 idea for White?

After the logical 7.c3 d6 8.d4, black should play 8....Bb6, with the idea 0-0, Re8, Bb7/g4, building up pressure against white's center. Also after 8.a4 Bg4!, pinning the knight and protecting the rook on a8, black should be fine.

Therefore, the main line is 7.a4, bringing the rook into play with an extra tempo. After 7....b4, white obtains the advantage by 8.Nxe5! Nxe5 9.d4 Bxd4 10.Qxd4, attacking the pawn on b4. Note the difference with 7.Nxe5, where black is fine after 7....Nxe5 8.d4 Bxd4 9.Qxd4 d6.

Instead of 7....b4, the main line is 7....Rb8 and the game often continues with 8.c3 d6 9.d4 Bb6. This position can also be reached by 7.c3 d6 8.d4 Bb6 9.a4 Rb8. However, this move order unnecessarily gives black the extra option of 9....Bg4.

Recently, during the international tournament of the Isle Of Man, two top-level games were played that are important for the current theoretical status of the Ruy Lopez Arkhangelsk.

In the game Fabiano Caruana - Gawain Jones, black followed the recommendation given in a video series by Peter Svidler. However, during his home preparation, white found the refutation at move 23(!) and won the game (see reports on Chess.com and ChessBase.com).

Remarkably, the very next round, Magnus Carlsen repeated the same opening against Caruana. He deviated at move 14, but again Caruana had prepared a strong novelty. Nevertheless, Carlsen won (see reports on Chess.com and ChessBase.com).

Edit: In both games, Caruana chose the move order 7.c3 d6 8.a4, allowing 8....Bg4. Although this probably has a reason, I have no idea why this move order would be more precise.

      [StartPly "12"]

      [FEN ""]
      1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O b5 6.Bb3 Bc5 7.a4 (7.Nxe5 Nxe5 8.d4 Bxd4 9.Qxd4 d6)(7.c3 d6 8.d4 (8.a4 Bg4) Bb6 9.a4 Bg4) Rb8 (7...b4 8.Nxe5 Nxe5 9.d4 Bxd4 10.Qxd4) 8.c3 d6 9.d4 Bb6


Queen's Gambit Declined: Marshall Gambit, how to decline it and keep full equality?

I don't know really know the theory here, but I can give some pointers. Maybe they are of some use for you or other readers.

The setup with c6/d5/e6 in the first three moves against white's d4 and c4 is called the Triangle; usually black wants to aim for the Noteboom variation (1.d4 d5 2.c4 c6 3.Nc3 e6 4.Nf3 dxc4 and roll with the queenside pawns).  4.e4 is white's most ambitious and sharp way to attack the Triangle. After 4.e4, you won't see any transpositions to other well-known openings.

If you're not looking for sharp lines, this is a bit of an odd move order to play, because besides the sharp Noteboom there's also this sharp Marshall Gambit to deal with. The Slav and QGD both offer better chances of a solid positional game than the Triangle, I think.

Scherbakov's book The Triangle System won awards and got great reviews; if you're going to play this seriously, that book should be your #1 source.

Black's main option besides accepting the gambit is 4...Bb4; the position looks a bit like a French Winawer (1.e4 e6 2.d4 d5 3.Nc3 Bb4) with the c-pawns on different squares. According to Scherbakov, "White does have a few ways to obtain a small edge, but Black's position remains playable." He also explains that play is rather different from normal Slav positions, and then spends 8 pages discussing it.

I general I suspect that as black, guaranteed quiet play and complete equality is a bit too much to expect in any opening. If you want to dodge white's sharpest options, you're going to have to make some concessions.


Does FIDE make any money from media coverage?

FIDE have sold the rights for the current world championship cycle to Agon. Given the very high levels of dissatisfaction with Agon it is unlikely that the contract will be renewed and the rights will revert to FIDE. There has been discussion of this on chess.com here.

Note that the moves of the game cannot be legally protected via copyright laws etc. Only the live pictures of the players playing the games can be protected like that. This has already been tested in the courts in several countries including the US (the most lucrative market) by Agon for previous matches.


Is taking the opponent's king an illegal move?

Capturing the King is an illegal move according to FIDE.

Refer to Article 1.2 from the Laws of Chess

  The objective of each player is to place the opponent’s king ‘under
  attack’ in such a way that the opponent has no legal move. The player
  who achieves this goal is said to have ‘checkmated’ the opponent’s
  king and to have won the game. Leaving one’s own king under attack,
  exposing one’s own king to attack and also ’capturing’ the opponent’s
  king are not allowed. The opponent whose king has been checkmated has
  lost the game.


Which variation of the Grunfeld Defense for White will lead to the most strategic and least sharp position?

Maybe 4.e3 is an interesting idea against the Grünfeld. Usually, black answers with 4....Bg7, but it should be noted that black can transpose to the Slav defence with 4....c6.

After 4....Bg7, white has two interesting options: 5.Qb3 and 5.cxd5.

5.Qb3 is probably the most popular continuation, attacking the pawn on d5. If black plays 5....dxc4, then white should be slightly better after 6.Bxc4. After 5....c6, a Slav defence-like position arises, which black players probably want to avoid. Therefore, 5....e6 is the most common response. Then, white can (temporarily) stop black from castling with the interesting move 6.Qa3!?, which has been played by several strong grandmaster like Nakamura (against Caruana), Ivanchuk and Dreev. After 6....Qe7?!, white obtains a clear advantage after 7.Qxe7+ Kxe7 8.b3.
The idea behind 5.cxd5 is to answer 5....Nxd5 6.Nxd5 Qxd5 with 7.Ne2 and 8.Nc3. This line has been played by several grandmasters, including Kramnik (in a rapid game against Svidler) and Andreikin.

Although my suggestion has some ideas and has been played by many grandmasters, it is far from the most principled continuation against the Grünfeld. Nevertheless, I believe it has some venom and could be a good try to surprise your opponents.

  [StartPly "7"]

  [FEN ""]
  1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 (4...c6) 5.Qb3 (5.cxd5 Nxd5 6.Nxd5 Qxd5 7.Ne2) e6 (5...dxc4 6.Bxc4) (5...c6) 6.Qa3 Qe7 7.Qxe7+ Kxe7 8.b3


What is the status of correspondence chess?

Correspondence chess is still alive and well. Just as in the pre-engine days it is the branch of chess which comes closest to chess "truth".

Before the internet and strong chess engines correspondence players had days rather than minutes and seconds to consider their moves. They could use books with openings and analysis by the best players in the world. This extra help allowed the best correspondence players to play chess at a higher level than even the top over the board players who had to play all their moves in 5 or 6 hours.

Nowadays strong engines substitute for the earlier forms of help but the result is pretty much the same. The best correspondence players play the best chess, better even than the engines unaided.

Note that top chess players, like Boris Gelfand for instance, are quite scathing about the capabilities of engines in many positions.

This is also something I've seen at first hand in some of my games. A couple of times recently I've reached an endgame I thought was going to be winning only to find that there was no way to do it. Later, looking at the game with an engine it gave me +1 or +2 but couldn't give me a winning line.

Engines are useful for avoiding blunders and checking lines but when an engine gives a position a good plus score you should always check it with "the human eye" before you use it in your preparation.

Of course now with email it is possible to play correspondence chess much cheaper and easier than in the old days. There is also much less chance of moves getting lost in the post.