Should you let your opponent know if they have forgotten to press their clock?

In my personal opinion, if you have noticed that your opponent has forgotten to hit their clock, the unwritten rules of good sportsmanship dictate that you should advise your opponent of such. It can become distracting to both players, though, if you have to do this more than twice.

So the real question comes down to the legal technicalities.

Are you even allowed to make your move before your opponent hits his/her clock? The USCF rules, at least, are not very clear about this. But it does not seem to be illegal at all. Many people feel it is bad form to move before your opponent has pushed the clock, but such a rule would be unenforceable from a practical perspective.

What about in sudden death? Tournament Directors and Arbiters are generally directed to not interrupt the game to point out illegal moves when in sudden death. So even if this were a rule, it likely would be set aside in sudden death.

Other than information about time delays and time controls here is what the USCF says about the clock:

6.) Except for pressing the clock, neither player should touch the clock except:
   6a.) To straighten it.
   6b.) If a player knocks over the clock a penalty may be assessed.
   6c.) If your opponent’s clock does not tick you may press his side down and
        re-press your side; however, if this procedure is unsatisfactory, please
        call for a director.
   6d.) Each player must always be allowed to press the clock after their move is made.
   6e.) A player should not keep a hand on or hover over the clock.

Back in 2008 there was a bit of a controversy about these questions regarding the clock. For the most part things have just been left up in the air. So in summary, it is not your responsibility to advise your opponent, many people feel it is good form to do so. But if it appears that your opponent is habitually forgetting to press the click, I would just continue on with the game and not advise him or her more than twice. There is no reason that this should interfere with your enjoyment of the game and ability to concentrate. Ultimately, in the USCF, the rules put the onus on the individual to press his own clock.

Kasparov v. Karpov, 1987 (pointed out by Tony Ennis) from the AP Archives

  For almost three minutes, members of Kasparov's delegation looked on
  helplessly as his time slowly ticked away. Under the rules, neither
  they nor the match arbiter could warn Kasparov of his mistake. When he
  finally noticed, Kasparov had less than a minute left for 14 moves. As
  he desperately played move after move, Karpov closed in with a
  crushing mating attack. "It's really a very bad psychological shock,"
  Spanish chess writer Fernando Urias said. "Kasparov has not only lost
  right at the start of the championship, but he also lost playing with
  the advantage of white."


How does one analyse openings judged dubious by engines?

Forget the engines. We are humans (hopefully) and are only interested in how human's play.
The King's Indian Defence (KID), a favorite opening of Tal, Fischer and Kasparov (and now played by Nakamura), has a reputation of being unsound by the engines (some positions are +1 and even +1.5) however for white playing precisely is very difficult.
For instance, the Mar del Plata Variation
[fen ""]
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nc6 8. d5 Ne7

Stockfish evaluates it to be +1 at a depth of 40.
Simple advice for practical play is to ignore the engine evaluation and focus on the fundamentals in the opening (in the order):

Exert pressure over the center (either classical or hyper-modern way)
Develop minor pieces
King safety
Connect the rooks while developing the queen

Needless to say always look out for short tactics as you follow the above and also try to have all your pieces coordinated.


Zugzwang.
OK, one word is a bit short for an answer. :-) Still, I would win that one for White probably on blitz time. Note that Black has only one passer and your knight easily can put a cork to that. Thus, with still one minute on the clock:

Play the N to f4 to kill Ph5.
Black of course will object to that, playing Pe5 in time.
Fine, then play the N to d3. The Pe5 now hangs.
Either he goes to e4, now you can catch the Ph5 and easily be back in time, or Kf6, same result.
Assume Black is lucky and manages to play Pe5, Pf4 without getting massacred. OK, same as before,
the N gangs up on Pf4, he must go to f3, the K can capture it.
After that, back to the Ph5.
Finally, queen the remaining Ph2 and mate.

A final warning. As Black I will try to let you play the N to f4, and when you capture h5, I have the K on g6, play e5 and YOU are in zugzwang. With one minute on the clock, I won't ponder if g4 still is won after f4 (it most surely is, but panic on the streets of London), but rather play the cool Nd3 instead of Nxh5 and we're at point 6 of the plan again.
Black can do zilch about this plan, White can execute it without much thinking.
To learn:

No swapping of pawns if you are up a figure.
No rushing in endgame. (As I commented above, bof's plan Ng5, Nxf7 also wins but do that only if you trust yourself, and Black can also foil it with Pf6.)
No allowing of muddling the waters when you have a technical win.
Make a decent plan.
Make it in easily executable parts.


Is this the correct flow of a chess game?

I don't think it's going to work. Consider this fragment:

You don't "kill enemy" just because your pawn can do the capture. What if your pawn capture exposes your queen behind? What if your pawn capture leads to back-rank mate?

Furthermore, you're not making yourself clear how to choose between moves. Your flowchart implies your program would be making legal pawn moves before considering anything else. This won't work.

You'll have to do searching, something like alpha-beta/nega-max. Your flowchart is way too simple for a reasonable chess engine, if that's your goal.

There won't be any "challenge" from your flowchart. I estimate the program would play no better than a random player. However, if your aim is just to make something that can play a legal chess game; your flowchart is reasonable. It's also a nice mini-project for practising programming.


After 6.Re1, black equalizes comfortably after 6....Nc5, as he wins the bishop pair. For example, 7.Bxc6 dxc6 8.Nxe5 Be7 9.d4 Ne6 10.c3 0-0.

Instead, 6.d4! is the main line, after which 6....b5 7.Bb3 d5 8.dxe5 Be6 is almost forced for black. The resulting position is the tabiya of the Open Spanish.

      [StartPly "10"]

      [FEN ""]
      1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.Re1 (6.d4! b5 7.Bb3 d5 8.dxe5 Be6) Nc5 7.Bxc6 (7.Nxe5 Be7) dxc6 8.Nxe5 (8.d4 Ne6) Be7 9.d4 Ne6 10.c3 O-O


The effect is small. On average, once out of every 20 rating periods a person plays rated games, a person's rating will be rounded up instead of down. A rating period is one month. Assuming everyone plays every rating period (which of course is not the case), this will create 30 points every 50 years.

There are known deflationary effects from new players - they often enter near the bottom, then gain points, and usually never lose all the points they gain. It's possible the rounding is intentional as one way to insert an inflationary pressure to combat that.

I don't think they will institute decimal points on ratings, regardless. The USCF uses a rating system with a decimal point and a complicated formula. The FIDE rating system, in contrast, was designed so anyone could calculate their own rating change based on their results and the published ratings of their opponents.  Adding decimals would make the math slightly more complicated and would make it necessary to publish those decimals for people to calculate their ratings.  We've already seen a GM throw a game in protest at perceived unfair pairings; even though pairings are deterministic and were not manipulated in that case, the pairing rules are complicated enough that the GM couldn't easily determine this at the time. Perhaps FIDE doesn't want them questioning their ratings as well.


Spotting "weird" computer moves is not difficult. Let me give you an example which you will agree is very clear. It is taken from the last round of the Boeblingen open in December 1999. The white player, Allwermann, was a 55 year-old German player who had been about 1900 strength (according to his German rating. FIDE ratings didn't go that low in 1999) for the previous 20 years. Going into the last round he was on 6.5/8 with the prospect of a first prize of DM 1,660 if he beat his grandmaster opponent. After 30 moves Allwermann was already winning and was to move in this position. See if you can guess his next move. Here are some candidates: Rd7, Rxb7, Rxf6, Qa7. Which one would you choose? Which one would be the last one you would choose?

[title "Allwermann,Clemens - Kalinitschev,Sergey (2505)"]
[fen "r6k/1p3Rpp/p2p1bq1/3N4/2P5/1P6/P1b2QPP/5RK1 w - - 0 1"]

1. Rxf6 (1. Qa7 Rg8 2. Qxb7 Be4) gxf6 2. Qxf6 Qxf6 3. Rxf6

In the Qa7 line Black's last move, Be4, threatens mate. The only move to stop it is Nf4.

Allwermann played the Qa7 line.

Fritz 5.32 evaluated Rd7 as +2.78 and Qa7 as +2.88.

This was written up in a Chessbase article in 2011. This is what the article said of this move:

  If you switch on multiple-variation mode you will see that Fritz
  thinks 31.Qa7 is a tenth of a pawn better than the other alternatives.
  A computer program simply doesn't understand the difference between
  cast-iron moves that cannot fail, and a tight-rope walk on the edge of
  the precipice. I venture no human would undertake the latter course in
  the given tournament situation.

That sums up the difference between normal human moves and weird computer moves. At least it did up until AlphaZero came along.

Here is the full game. See how many obvious computer moves you can spot.

[title "Allwermann,Clemens - Kalinitschev,Sergey (2505)"]
[fen ""]

1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 e5 5.Nb5 d6 6.c4 Be7 7.Be2 a6 8.N5c3 Nf6 9.O-O Be6 10.Be3 O-O 11.Na3 Nd7 12.Qd2 Nc5 13.Nc2 f5 14.exf5 Bxf5 15.Bf3 Kh8 16.Bd5 Qe8 17.Rad1 Qg6 18.Na3 e4 19.f3 exf3 20.Bxf3 Ne5 21.Nd5 Bh4 22.Nf4 Nxf3+ 23.Rxf3 Qe8 24.Nd5 Ne6 25.Rdf1 Qg6 26.b3 Rf7 27.Nc2 Ng5 28.Bxg5 Bxg5 29.Qf2 Bxc2 30.Rxf7 Bf6 31.Qa7 Rg8 32.Qxb7 Be4 33.Nf4 Qf5 34.Qd7 Qe5 35.Kh1 g5 36.Nh3 g4 37.Nf2 Bf5 38.Nxg4 Be4 39.R7xf6 Bxg2+ 40.Kxg2 Qe4+ 41.Kh3

In the final position after his GM opponent had resigned Allwermann couldn't resist telling his opponent that it was mate in 8. Of course he was right.


Get Arena!

Setup Arena on your iMac and Ubuntu computer. Register a computer account for each computer on a server of your choice. Of course, both computers need to login on the same server. Let one computer request a match and let the other computer accept the match.

That's it.

Arena is pretty cool. It wouldn't surprise me if you could create a script to automate a bunch of stuff you would want to do.


Where can I download and how do I set up a 5-man tablebase in Arena GUI?

http://www.cruxis.com/chess/manual/end_game_table_base_support.htm

This is from the developers of Houdini's site.


You can use "Chess Query Language" for coding this, as it will be quicker to work with and easier to understand.


See for yourself: https://lichess.org/analysis/standard/3K4/q5q1/8/8/q5q1/8/8/q2Bk1q1_b_-_-

It's Qa1d4 for total unambiguity. I imagine this corner case is not covered by every PGN reader though.

Qa1d4
Qa4d4
Qa7d4
Qg1d4
Qg4d4
Qg7d4


According to the FIDE Laws of Chess

5.1        The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was in accordance with Article 3 and Articles 4.2 – 4.7.
8.7    At the conclusion of the game both players shall sign both scoresheets, indicating the result of the game. Even if incorrect, this result shall stand, unless the arbiter decides otherwise.

The "winner" won the game. However, both players signed both scoresheets indicating 0.5 - 0.5, so that would be the result unless the arbiter were involved.

In this case, I think the arbiter made a mistake. The young junior should have stuck to her guns and kept the 0-1. She agreed to mark it a draw because she didn't understand that she won regardless of her opponent realizing he was beaten. Were she an experienced chess player, I would absolutely let the 0.5 - 0.5 stand, but I think you need to help young players understand the rules without penalizing them for trying to avoid conflict. I think the gender dynamic and potential age dynamic (you explicitly mentioned she was young, but made no mention of his age) should also be considered in the decision.


Software for opening repertoire practice

Chess Position Trainer is really great! I use it very day and love it a lot.

Still, there is no IOS version yet.


Converting from Algebraic notation to Coordinate notation

You can do this easily in python using the python-chess module and using the parse_san function of chess.Move.

Let's call the script algebTocoord.py:

import chess

testfen = 'rnbqkb1r/pppppppp/5n2/8/3P4/8/PPP1PPPP/RNBQKBNR w KQkq - 1 2'
board = chess.Board(testfen)
algmove = 'Nf3'
coordmove = str(board.parse_san(algmove))
print coordmove

the printed output is:

'g1f3'

This was tested using Python version 2.7.16 and the 0.22.1 version of python-chess.


Where to start with a child learning chess?

Does it make most sense to just start playing with setting up all the
  pieces, or are there smaller "games" that one can/should start with?

It doesn't really matter the age of the person learning to play, there is no point in starting with a full set. There is just far too much to take in and make sense of. The first thing to do is to teach them how to win!

So, first teach them how king, queen and rook move and then teach the basic mates -

KRR v K
KR v K
KQ v K

And I would do it in that order because it is the easiest and it is the way to introduce concepts like checkmate, king not allowed to move into check, two rooks working together, opposition, king and one rook working together, stalemate (to be avoided with KQ v K).

Next I would go on to KP v K, when you can win, when it is a draw and how to win.

Then I would go on to a game which many people start with (but there is no checkmate, so less fun IMHO) and that is 8 pawns v 8 pawns. Winner is the first to get a pawn to the other side or to "stalemate" the opponent - i.e. the opponent is the first to run out of moves.

After that I would reintroduce the kings and major pieces before finally going on to the full game.

You can see I'm working backwards here because that way the learner first learns where they should be aiming to get to and what to when they get there in stages starting from the destination.


There is a well known article called The Evaluation of Material Imbalances
by GM Larry Kaufman, first published in 1999 in Chess Life, winner of the 'Best Instruction' award from the Chess Journalists of America, that has the bishop pair valued at half a pawn.

A quote from the article (linked above):

  "The bishop pair has an average value of half a pawn (more when the opponent has no minor pieces to exchange for one of the bishops), enough to regard it as part of the material evaluation of the position, and enough to overwhelm most positional considerations. Moreover, this substantial bishop pair value holds up in all situations tested, regardless of what else is on the board. This large a bishop pair value is surprising because in the opening grandmasters will often give up the bishop pair to double the opponent's pawns or to gain a mild lead in development, factors which are generally not worth half a pawn..."

That same article values the other pieces like so:
King = 4 (endgame)
Queen = 9.75
Rook = 5
Bishop = 3.25
Knight = 3.25
Pawn = 1

Whether you wish to rely on such figures is up to you. Personally I think you would be better off exploring why the bishop pair is considered an advantage, and when. The best explanation I've seen is in Ludek Pachman's Complete Chess Strategy Vol 1.. Some of the points he raises:

  "In open positions their effectiveness is an extremely important factor."
  "...the opportunity of purposeful simplification."
  "The side with the two bishops can bring his king to the centre more easily under their protection"
  "...helps by preventing the enemy king from using the otherwise weak squares of a certain colour."


I assume you are asking how to force your opponent to stalemate you, rather than vice versa.

Get rid of almost all of your pieces, except for your queen or rooks, or pieces that are pinned against your king.
Make sure all your pawns are blocked and can't move.
Make sure your king has no legal moves.
Check his king relentlessly with whatever pieces remain, feeling free to place the pieces where they can be taken, such as adjacent to his king.
Ideally, you are now in a situation where either he will be subject to perpetual check or he will take all your remaining pieces and you will be stalemated.

Keep in mind that this is not an actual strategy that ever works except 1) against novices, 2) in blitz games, or 3) in very rare circumstances in serious games. But those circumstances do exist. Generally you find that two of the first three steps in this process have already happened and start looking for ways to engineer the rest. Evans-Reshevsky is the most famous example of a stalemate swindle in top-level play.


How do I respond as Black to 1. e4 e6 2.e5?

Respond with 2... d5. If White plays 3. exd6, then 3.. Bd6. White has wasted 3 moves on the e-pawn, and after that Black has one piece developed against white's zero.
Normally White just follows 2... d5 with 3. d4 and we're back into the regular French Defence advanced variation.


Are engine ratings directly comparable to human-level play?

What you have to understand is, first, that any rating is just a comparison of players within that pool. So a 2200 on chess.com is not the same as 2200 on lichess.com, or on ICC. They are probably close, but it is not the same.

Second, you need to realize that your three game sample is just not enough to draw any valid conclusions. You are human, so even if your winning expectancy were .95, you can always defy expectations, and make a blunder, and the computer, even handicapped, would still likely take advantage of it.

Lastly, at 2200, you are playing a handicapped computer. It is playing "not best" moves, but how is it playing them? Is it being told to play the fourth best move every time, or is it being told to play the best moves every time, but on the 5th move, play the 10th best move? Either way, you could have an anomaly where it plays less bad moves in an individual game, and when those worse moves do pop up, maybe you miss the opportunity.

The computer can only be handicapped so much.


In online chess with long time controls, does having a title encourage opponents to cheat against you?

I've displayed an FM title and never noticed a problem with cheating once. Your question is the first time I've ever thought about the concept of someone wanting to cheat more against a titled player.

If anything, most players would want the opportunity to get to play a titled player, and wouldn't waste it by cheating with an engine. How do you know that his opponents were cheating in most of his losses?


Guidance on a new idea for an engine design?

I see three ways of tackling this:

You can add a confidence value to you position evaluation function. And then use this to improve your tree search. This sounds amenable to mathematical analysis, you'd have to adapt min-max search to handle a trade-off between confidence and evaluation.
You can output a distribution of evaluations instead of a single numerical value. And again use this information to improve tree search. That's similar to the one above.
You directly output a "how much compute should be spent on this position"-value.

The second thing has been done in some of Deepmind's video game reinforcement learning projects. So you might want to take a look at that.

I haven't seen anything like this for turn-based board games. It certainly sounds like a sensible idea.

If you want to do the third thing you need to figure out how to capture and backpropagate "how much compute should be spent on this position". That doesn't sound trivial and is not guaranteed to work, but it would be pretty neat and it would tilt your work more towards Deep Learning kinda stuff.

No, you should not use genetic algorithms. It's almost always better to optimise your function non-randomly. In your case backpropagation is highly likely to be much more efficient.

One pitfall is that even backpropagation might not be efficient enough. If you train your networks from scratch by self-play on your laptop, it is possible that the learning never really takes off. Self-play doesn't provide enough information for efficient learning, which is why AlphaZero and co use humongous amounts of compute.

So it might be more sensible to plan your training in such a way that it can use existing games. Then evaluation and confidence can be learned without doing any tree-search yourself.


Obtain information about a a position from Stockfish

If you do not want to use a library/API to get this information, then you will need to implement some parsing to get it, but in principle (almost) all the info you need is available via (non-standard) UCI commands:

Legal moves

Perft lists all legal moves. E.g., for the starting position go perft 1 gives you:
a2a3: 1
b2b3: 1
c2c3: 1
d2d3: 1
e2e3: 1
f2f3: 1
g2g3: 1
h2h3: 1
a2a4: 1
b2b4: 1
c2c4: 1
d2d4: 1
e2e4: 1
f2f4: 1
g2g4: 1
h2h4: 1
b1a3: 1
b1c3: 1
g1f3: 1
g1h3: 1

Nodes searched: 20

2.+3. Game state
d is a non-standard UCI command in Stockfish to print debug information. It contains information like the FEN and pieces giving check, e.g.,
position startpos moves e2e3 f7f5 d1h5
d

 +---+---+---+---+---+---+---+---+
 | r | n | b | q | k | b | n | r | 8
 +---+---+---+---+---+---+---+---+
 | p | p | p | p | p |   | p | p | 7
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 6
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   | p |   | Q | 5
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 4
 +---+---+---+---+---+---+---+---+
 |   |   |   |   | P |   |   |   | 3
 +---+---+---+---+---+---+---+---+
 | P | P | P | P |   | P | P | P | 2
 +---+---+---+---+---+---+---+---+
 | R | N | B |   | K | B | N | R | 1
 +---+---+---+---+---+---+---+---+
   a   b   c   d   e   f   g   h

Fen: rnbqkbnr/ppppp1pp/8/5p1Q/8/4P3/PPPP1PPP/RNB1KBNR b KQkq - 1 2
Key: 47C539B3DEE3D29B
Checkers: h5

In order to determine whether it is checkmate, you need to check whether perft 1 is zero and checkers from d is non-empty.
For draw detection I think there is no straightforward way to do it with plain Stockfish. The only draw that can safely be detected is stalemate, similar to the checkmate detection mentioned above.


Can a win be claimed on the second illegal move if the first wasn't raised?

Black attempts to claim a win under 7.5.5. Does this stand?

No. According to 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.

After the first illegal move the arbiter gives the opponent an extra 2 minutes. He will also explain his decision to the two players and warn the player that a second illegal move will lose the game. Punishment for a second illegal move can only occur if the punishment for the first illegal move has been made.

There are recent judgements (for which I don't have reference to hand, but I suspect came from one of the FIDE Arbiters Magazines) saying that only one illegal move can be punished at a time. For instance, if a player promotes illegally by not replacing the pawn while still in check, he can not be punished for two illegal moves.

Therefore after the first reported illegal move only the punishment for a first illegal move can be applied. Another illegal move must occur for the punishment for a second illegal move to be imposed.

  Could white have claimed a win had he summoned the arbiter after
  22...0-0-0?

No, the same arguments apply.

  Extension: if the claimed win(s) does (do) not stand, under 7.5.1,
  from which position does the game resume?

From the position before the first illegal move. The punishment and reinstatement of the position are unrelated. Article 7.2.1 is relevant here -

  7.2.1 If during a game it is found that the initial position of the pieces was incorrect, the game shall be cancelled and a new game shall
  be played.

Regardless of fault or punishment the entire game should be played according to the FIDE Laws of chess.

Note, I had a very similar problem arbiting a tournament in 2014 when a player came to me to report a third illegal move by his opponent and claim the game. Since it was the first illegal move he reported I treated it as the first illegal move. Since the previous illegal moves had involved his opponent not getting out of check and the position corrected by the players at the time there was no need to go back beyond the current move.

PS Before tieing oneself into gender-anguished knots it is worth noting this line in the introduction to the FIDE Laws of Chess -

  In these Laws the words ‘he’, ‘him’, and ‘his’ shall be considered to
  include ‘she’ and ‘her’.


What are the best openings in Antichess?

It was discovered that e3 is a win for White:

http://magma.maths.usyd.edu.au/~watkins/LOSING_CHESS/ICGA2016.pdf


Has any chess engine developed its own opening book?

Yes, top level engines' authors generally also prepare an opening book with their engine.
But this process does not only involve computer matches. They make use of both computer matches, GM matches, and machine-learning (which you explain in your question)
This page has an interview about this topic on Rybka 4 book.
A quote from the page:

Q: Your Rybka 4 Aquarium opening book will be released soon. It's clear that you put a huge amount of work into the book.
A: Yes, I put a lot of work into it. It helps that I find it really interesting to analyze unknown positions and ideas from chess books, chess practice or computer games and find my own solutions. Today's opening preparation is very deep. In some cases players know their lines from the opening all the way to the endgame. A less prepared opponent will probably lose his way somewhere in the middlegame against such preparation. Things are looking even worse in computer games - long lines, often 50 moves or more, leading to a draw are similar to pre-arranged draws in human games.
The technical advances mean that opening analysis is very different from what it used to be a few years ago, not to mention a few decades ago. However, even with today's amazing computer tools, the work of the modern opening book author is still very demanding.
My method of creating a strong opening book consists of several steps. Assuming you already have a good database, the first step is the selection of games. Making a good hand-typed book is impossible. The selected games serve as the "raw material," and generate the initial version of the book. This step may only require a few hours of work. The next step is to fine-tune the move priorities. This is a very time consuming task, and in the case of the Rybka Aquarium book, it took a few weeks.
Testing the book is an independent process. First you run a test and then you look at the results and try to find weak points in the book. After further analysis you may find some improvements, which require updates to the book and another test cycle must be run. This process will take a few days.
Last, but not least is the creative phase of making an opening book. Here you need to find new ideas and get a deeper understanding of the lines in the book. One recurring question in this phase is why engines give a low evaluation, or play badly positions which are very good according to my own understanding of the position. This phase is not only very time consuming, it also needs a lot of creativity and manual interaction and guiding of the engine analysis.


Double-click on the Stockfish executable, type "uci" (without the quotes) and hit Enter. You should get some output, near the top of which should be a line beginning with "id name", and this line gives the name of the engine, including the version number. (You may need to scroll up to see the "id name" line, if there's a lot of output.)

The same method works with any UCI engine.

Note that the Stockfish executable supplied with Scid vs PC is in the bin\engines\stockfish subdirectory of the Scid vs PC installation directory. The version of Stockfish included in my (recent) copy of Scid vs PC identifies itself as Stockfish 240813 64, which is a bit odd (perhaps it's a version compiled from source by the developers of Scid vs PC), but the file date suggests that it's roughly the same as Stockfish 4.


Would an erroneous claim of mate be considered as annoying the opponent, cheating, an illegal move, or something else?

First, kids and adults, the rules are the same, so there is no difference there.

What you are asking about goes beyond just the rules: It comes down to intent.

Whether an adult, or kid, there could be an erroneous claim; and if it is really just that, then the TD should just fix it assuming it is caught in time. It is just a mistake. Other types of mistakes would be similar.

This might be hard to prove, but it an opponent did it just to cheat or annoy, then yes, that would be a breach of the rules, and should be penalized. The real question is how do you prove that? Short of the person having done it before, or bragging about it, I cannot see how a TD would impose sanctions upon someone for what otherwise looks like a human mistake. I think the TD has to assume it is a mistake unless otherwise proven, which again, may be next to impossible. Even without that proof, if the TD suspects, a warning may be in order that future incorrect claims may be sanctioned.


Can the Nc3+e3 Chebanenko Slav, the Exchange Slav and the 4...Bg4 Slow Slav transpose into each other?

No, they don't transpose to Exchange Slavs.

In the Slow Slav and the Chebanenko, white plays e3 to prevent trouble with the c4 pawn. The bishop stays inside the pawn chain which is somewhat passive, but the plus is that c4 is defended, so that black can't stir up trouble by taking it and defending it with ...b5.

In the Exchange, white has dealt with that issue drastically by just exchanging the pawn away, so there's no need to make further concessions because of threats to it. I've never seen an Exchange Slav where white chose to keep Bc1 inside the chain, it goes to f4.


Why is an early e5 against a Yugoslav setup evaluated at +2.6 according to Stockfish?

This move creates several weaknesses, at f6, d5, and d6, and restricts the movement of the Bg7.
The outpost weakness is usually shown by the game https://www.chessgames.com/perl/chessgame?gid=1257953.
The d6 weakness is basically using all you pieces to attack the pawn and, once all of black's pieces on defending it, to shift the attack to another point and, hopefully, the black pieces can't respond quickly enough.
The f6 weakness is harder, but basically pushing a pawn to f5 forces black to capture and expose f7 to attack.
The restricted movement of the bishop is exploited in the endgame when the bishop can't react quickly enough to both protect d6 and the dark square weaknesses.


Does the Caro-Kann or the Tartakower System of the Queen's Gambit Declined help with positional skills?

Based on the sentence syntax I don't believe that the author is intending to make a connection between the mentioned opening systems and positional skills. Every strong player must have good positional skills and must also be a good tactician. You could not become a world class player without both.

Both of these openings do have strong positional ideas and Makogonov (who would be classed as "positional") played them both. So it is likely that he taught them because he believed that they were instructive and because he was familiar with them.


What are the laws concerning copyright of chess games?

Chess games without annotation can't be possibly copyrighted. You don't need to inform them. You don't need to acknowledge them.

I've been using Carlsen's games (without annotation) for commercial. I literally sell his moves and the games. So far, the world champion has not complained.

Game annotations are protected by the laws. Make sure you only use the game moves.

@itub has some links, such as:

https://chess24.com/en/read/news/us-judge-agrees-with-chess24-on-chess-moves


No. You shouldn't count null-move in repetitions because:

Null-move is fake
Null-move artificially creates a repetition when there is none

Your implementation is correct, but you might want to exclude null-move. Let's take a look at Stockfish:

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

bool Position::is_draw(int ply) const {

  if (st->rule50 > 99 && (!checkers() || MoveList<LEGAL>(*this).size()))
      return true;

  int end = std::min(st->rule50, st->pliesFromNull);

  if (end < 4)
    return false;

  StateInfo* stp = st->previous->previous;
  int cnt = 0;

  for (int i = 4; i <= end; i += 2)
  {
      stp = stp->previous->previous;

      // At root position ply is 1, so return a draw score if a position
      // repeats once earlier but after or at the root, or repeats twice
      // strictly before the root.
      if (   stp->key == st->key
          && ++cnt + (ply - i > 0) == 2)
          return true;
  }

  return false;
}

You already have st->rule50 in your code (board->fifty-move) but you don't have st->pliesFromNull.

Let's check what Stockfish author said about pilesFromNull.

  http://www.talkchess.com/forum/viewtopic.php?start=0&t=35052&topic_view=flat&sid=46a5561bcd0c4d36796c0fbfe5158079

By Joona Kiiski (2010):

They are already excluded, note the use of st->pliesFromNull:

Null moves can artificially create a repetition
draw where instead there is no one.

So use a second counter to reset history after a null move.

You see, if the strongest engine in the world does it you have no reason for not doing it.

If you check the code carefully, the first time when you do a null-move pliesFromNull is 0.

void Position::do_null_move(StateInfo& newSt) {
    ....
    st->pliesFromNull = 0;
}

later the engine increments the counter in do_move:

++st->pliesFromNull;


Avoid the trap of studying openings, they don't improve your game. Say, at most 10% of your training time before you start making IM norms. They can be addictive and maybe even improve your results in the short term, but in the long term they just don't improve your chess playing.

The basis of improvement: playing serious, slow games (say at least half an hour on the clock) against decent opponents, afterwards if possible exchange thoughts about the game with your opponent (go through the game again). Then, before you forget them, write down as much as you remember about your thoughts during the game. Why did you play moves, but also why didn't you play others. Which moves of him surprised you. Then, go over the game again and check your thoughts. Was the line you were afraid of when you didn't play that move really so dangerous? That attack looked good, wasn't there a way to win? And so on. Find your mistakes, and don't make them again.

Play through well-annotated grandmaster games.

Learn how to win endings where you're material up, or draw them even when you're material down.

Train tactics on Chesstempo.com.

Play real tournaments over the board.

Once you're of sufficient strength (1600-1700ish over the board), start working through Yusupov's orange books. They have hard exercises covering a wide range of subjects you need to get good at. But that's probably for later.


How much does adding an opening book to a relatively weak chess program affect its strength?

Stockfish gains about 50 elo from the Cerebellum opening book ("Brainfish" is just Stockfish equipped with Cerebellum).
I don't know if the effect of opening books varies depending on engine strength, however.


Is there a standardized chess test that can measure one's chess playing condition?

I do not know of any such standardized chess test.

But here are some general questions you should ask yourself. The "correct" answers are provided in parenthesis. If you answer all correctly, you should be in good shape.

Physical Preparation

  Have I had enough sleep? (Yes)
  Have I had enough food to give me sufficient energy for the game? (Yes)
  Have I over-eaten? (No)
  Do I feel stressed out? (No)
  Is my body in good shape without any kind of aches? (Yes)
  Are my eyes relaxed? (Yes)
  Do I feel sick? (No)
  Do I feel fresh? (Yes)
  Do I feel tired? (No)

Mental Preparation

  Is anything bothering me? (e.g. angry exchange with co-worker) (No)
  Is there something else on my mind that can be a distraction (e.g. date with girlfriend)? (No)
  Do I have a headache? (No)
  Am I under the influence of alcohol or any such other drug? (No)

Chess Preparation

  Have I made good opening preparation for the game? (Yes)
  Am I afraid of my opponent? (No)
  Have I practiced chess tactics recently? (Yes)
  Am I confident that I can play well? (Yes)

If you answered all "correctly", you're in really good shape.

P.S. (I'll add more to the list as and when I remember)


This is a bug. The GamePigeon app was written by non-chess programmers, their focus is not on chess. They're not specalized in chess apps, chess is just one of the many things they do.


As T.S. Eliot said, "There is no method but to be very intelligent." If the opponent is smart enough to avoid the known short mates and understands basic opening strategy, you'll just have to outplay them.

That said, in my experience, new players often miss forks, discovered attacks, and moves that theoretically place a piece under attack, but where the capture would result in a check or expose an attack on a more valuable piece. New players are often so focused on protecting the king and/or queen that they blunder away pawns and minor pieces by leaving them vulnerable to such moves.

My advice: play better than the beginner and you will rapidly overwhelm them and find blunders to exploit. :)


Choosing the best move in the given position

After 1. Rac1, Black has the intermediate move 1...Nxc3, attacking the rook on d1, which forces White to play 2. bxc3, and then the pawn on a3 is hanging. So Black would likely go 2...Nxe3 followed by 3...Bxa3.

[FEN "r3kb1r/pp1q1pp1/2p1p3/3nPb2/3P1N1p/PBN1BQ1P/1Pn2PP1/R2R2K1 w - - 1 1"]

1. Rac1 Nxc3 2. bxc3 Nxe3 3. null Bxa3


How to highlight current and previous move of the player in chessboard.js?

I wasn't familiar with chessboard.js - but a quick search of their site turned up an example entitled Piece Highlight 1, which seems to do just that.  The link includes both javascript and HTML examples, depending on which you're looking for.

Since links are not permanent, here is the HTML example:


Programs to help beginners to practice Chess

Chess Tempo has a great section on openings used by real players as well as statistics regarding the openings(player win %, draw %, opponent win %, etc.) and also an interactive board which lets you step through each move of the opening.


Website or program that creates puzzles from blunders in your past games

I don't know of a single program that does all that. I do it myself with following steps. I save most of my games in a pgn file. The interesting ones, esp. my losses, are analyzed by Stockfish. The "blunder threshold" is your choice, typically 3 - 5 pawns or more. With Notepad++ text editor I enter the FEN of the position in a pgn file, of course preceded by the tag line [SetUp "1"]. Answer is best line of Stockfish. I skip positions that are cooked by good alternative choices.
When 50 - 100 puzzle positions are accumulated I transfer the pgn file to my Android phone & tablet. I display them with iChess but many other apps handle pgn files.


Does anyone know who currently owns Novag's intellectual property?

This is not a direct answer to your question, but it will be helpful. I happen to miss too the playing style of the early chess computers. Those machines ran amazing algorithms on incredibly poor hardware resources (usually 128 or 256 bytes RAM and a 2 to 16 Mhz, 8-bit processors with limited instruction sets, which would make anyone laugh when compared with the cheapest smartphone of today). The resulting game style at a few seconds per move was aesthetically decent chess (rooks placed in open lines, knights towards the center and so on) that tried to use the machine resources as good as possible (instead of being purposely dumbed down like modern engines) but with the so-called "horizon effect". This allowed the attentive human player to beat the computer by means of combinations whose final result was above the horizon of the few plyes the computer was able to examine, e.g. you could trick the machine with a sacrifice for instance, or you could detect a weakness in an otherwise apparently sound position.

Yes, as a result, those chess computers played what many people like me find more human than all the PC chess software that followed. With "modern" software (meaning PCs since ~1990) it is very noticeable when randomly stupid moves are inserted in an otherwise strong play, or when the program plays something ugly with not much sense positionally that does not win you immediately but also does not allow to be beaten with tactics. There is no way you can beat modern software by being tactically strong, that has never again happened since the 90s. It is incredible that almost no one has paid any attention to this, but the solution was very simple: limiting the calculation speed of engines until matching those of the early devices. Without altering anything else: no choosing of suboptimal moves, no random noise added to the evaluation function or anything. Just let the algorithm get the most out of a position but set a very low limit to the number of positions evaluated per second and you have it.

It has been done at least once: try the open source UCI engine Rodent II by Pawel Koziol. Set the parameter NpsLimit at something between 40 and 100 and allow it between 5 and 20 seconds per move. It really plays like those old chess computers.

I am unaware of other engines that implement that possibility. Some engines limit the search depth (Rybka) but the response is nearly instantaneous. Others emulate a slow response but it is not clear what they are doing (looking at the playing style I suspect Ufim might be following this approach but it is not explicit). Others choose suboptimal moves as said (Stockfish), but nearly any author has thought of implementing the full chess knowledge and positional evaluation at arbitrarily low speed, and I hope the idea is copied by many developers. Playing against such algorithms with horizon effect is fun, and it really gives you the impression of a fight against an opponent that is trying to do his/her best, instead of a mighty opponent that is playing sub-optimally on purpose. I think that is what your question is about.


It's hard to find resources like that. Beyond the basics or how to move, you can look at

Beginner Study Plan - I'd recommend having a look at this guide so you know what to study. Then I would advise you look at Yasser Seirawan's Winning Chess Series. For beginners, look at

Play Winning Chess

Then when you progress, you can look at

Winning Chess Tactics

and later you can look at

Winning Chess Endgames
Winning Chess Openings

These books are easy to read and provide lots of examples with very clear explanations from one of the best chess authors out there.

You should definitely learn all the tactical motifs that exist. By knowing what they are, you can try to find them in real games, and over time they will start to become second nature. I recommend Attacking Chess by Josh Waitzkin, which is a really good book for beginners learning tactical puzzles. You can probably find a PDF of the book online if you want, but I'd advise buying it.

Tactical Motifs - This website has tens of thousands of tactical puzzles and will show you the solution if you get the puzzle wrong. Each puzzle has a tag which lets you know what tactical motif was used. For a beginner, you should know forks, pins, skewers, double check, back-rank mate and x-rays. There are plenty more tactical ideas, but these will help most.


What is the name of this unconventional opening?

This set up is often called "The Hippo", a possible reason is that bishops look like the eyes of a hippopotamus.
For example: Eric Rosen: Don't Mess With The Hippo


To what move depth should you analyze a chess position

Generally, the only reason running a chess engine at less than maximum power are time constraints or if you want to give yourself a chance to win, though in the latter case I'd still prefer to play human players instead.

Regarding the use of a chess engine to analyze the position in an opening in order to learn a chess opening I am wondering how you are going to practically do this? I mean, the engine will give you only a certain sequence of moves which it considers best play for both sides. It will not teach you the ideas/plans behind an opening which is the most important part and something which you can rely on if your opponent for instance does not play the expected move. It will not teach you about subtleties, like move-order changes or any sidelines.

I am not saying a chess engine is completely useless for studying openings. You could use it for practice games in a specific opening or you could study a certain alternative move in an opening (but that would be at a stage where you already know the opening somewhat).

For studying a new opening I'd find much more useful than an engine:

any explanation of plans/ideas (this can be books, videos, or a coach/friend)
a database
following games of a Grandmaster who is playing the opening regularly (let them do the difficult analyzing part...)


Wrong lines of play to illuminate right lines

A healthy approach towards learning openings is to retain the key ideas involved, and not to necessarily memorise move by move unless it's an extremely precise sequence in a very theoretical line (as is often the relevant case at high level chess). It's a bit analogous to how one would learn physics, by understanding the principles, drawing connections between them, learning to how reason with them and so on, such that ultimately, you can reconstruct theorems in your head, as opposed to memorising them symbol by symbol.

Now in chess, understanding the ideas in the opening phase simply starts by asking yourself questions when you're exploring an opening: for example: "what is the point of an early h6 here? what I am preventing and why is it with such priority?" or "what is Qc2 achieving in this situation? can't I achieve the same with Qd3?" or "Could I not have played Nf6 first without loss of tempo?"  and so on.

In trying to answer those questions for yourself, you will automatically uncover the pitfalls, or the wrong/less optimal alternative moves, without necessarily seeing them listed in a book. Now of course one can never exhaustively do so, as there are simply too many variations in each opening or certain very hard to grasp ideas involved, and that's why there are thick books written on almost every opening, but that said, the essential part of any improvement you are going to make, will result from the struggle of trying to understand a position on your own. It is this struggle that will form your mindset for how to reason about openings in general, one that will continuously evolve for as long as you study chess.

Now in order to find the answers to the type of questions I had mentioned earlier, you need to consider two important aspects: a) a general strategy in mind for what the opening is trying to achieve, b) a concrete assessment of the variations involved such that the strategy in a) can be efficiently implemented, i.e., avoiding redundancies or other loss of tempi, not creating weaknesses or easy targets, and worst case avoiding blunders. This is the part where engines can immensely simplify the task.

Both are equally important. Luckily, the bulk of opening theory we have stems from human play and not computers, meaning players at some point attempting to tackle a certain move differently by emphasizing a set of key new ideas. Luckily, because it means we have a chance of understanding them if we manage to trace the original ideas.

In your example: the essential part of the Dragon variation for black in the Sicilian is the fianchetto'ed bishop on g7. Simply put, unlike most other Sicilian variations where the dark-squared bishop has very little active scope (instead being developed as a purely defensive piece), the Dragon is an alternative that provides more active prospects for the bishop, with a safe developement (fianchetto - making it hard to trade/challenge the piece) and with a follow-up that emphasizes undermining white's dark square control. This is a rough sketch that goes along the point a) we were discussing above. Now more along point b), namely the more concrete aspects of the opening, contains the answer to your Nf6 question: by not playing Nf6 too early you i) entertain the possibility of potentially developing the bishop to g7 with tempo, as it will directly eye the d4 knight and ii) you prevent the option of an immediate e5 from white.  As you show, Bg7 forces a reaction such as Be3 and then you include Nf6 (rendering immediate e5 less critical after Nxc6, see diagram) Whereas with for example 5...Nf6 (so before the bishop), you allow white an easy path to playing e5 closing down the long diagonal and dislocating your f6 knight. The comparison is illustrated below:

 [title "Importance of early Bg7 in Dragon"]
 [fen ""]

 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Nc3 Bg7 (5...Nf6 6. Nxc6 bxc6 7. e5 Ng8 {without tempo, white is free to develop aggressively, no tempo invested on Be3 or on the defense of e5} (7...Nd5 {with 5...Bg7 and Be3 included, this is a good gambit, with about equal play} 8.Nxd5 cxd5 9.Qxd5 Rb8 10.e6! fxe6 11.Qe5 {forking black's rooks : this tactical shot wouldn't be available after 5...Bg7}) 8. Bc4 Bg7 9. Qf3 e6 {rather forced} 10. Bf4 {white is objectively better as they have fully developed, they have the better minor pieces with central control, they have induced important dark square weaknesses in our position by forcing e6. Instead, black is critically under developed and without any real active prospects.}) 6. Be3 Nf6 7. Nxc6 bxc6 8. e5 Ng8 {the knight is retreated with tempo as e5 is under attack. Sure it's a bit slow, but black has a healthy pawn structure, a target on e5, and a relatively easy development to follow. Two main variations exist here, 9. Bd4 Qa5 and 9. f4 f6, see Kasparov-Ivanchuk 2002 for a nice example. }

So you see, by bearing in mind that with a tool such as the Dragon black intends to play actively and eventually for the initiative, and going through the respective variations of 5. Bg7 and 5. Nf6 we've come to the conclusion that Bg7 is the key move here for black in order to not lose pace with white's development/play while keeping active prospects open (make sure to go through the Ivanchuk game I mentioned in annotations).

In fairness, there are much simpler examples to use for the purpose of our discussions. Let's choose a line in the queen's gambit exchange variation (see annotations for discussions):

 [title "example #2: queen's gambit exchange variation"]
 [fen ""]

 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. cxd5 exd5 5. Bg5 c6 6. Qc2 {One wonders, why Qc2 so early? as opposed to e3 for example. In the exchange variation, black often struggles to create active play, and one reason is the c8 bishop which has a hard time of becoming useful. Qc2 is played early to take away the only remaining active bishop move, namely, Bf5!} (6. e3 Bf5 {black has developed their only potentially poor piece in this variation, as it went unchallenged by white.})

In short, in the exchange variation white is committal about the centre early on (cxd5) and continues to play actively with Bg5 forcing c6, followed by the simple usual setup of e3-Bd3-Ne2-f3 setting up e4 push (once castled of course) and a potential minority push on the queen-side. Concretely speaking, you want to achieve all this while not allowing black to develop easily or to create active play. So you start looking more carefully at the position, and only then realise the importance of nuanced moves such as Qc2. You may argue, why can black not play g6 immediately after Qc2 in order to revive the Bf5 idea while preparing to fianchetto the f8 bishop? whether or not a case can be made for that idea, the important thing is that this process of asking these kinds of questions and trying to find the answers to them on your own is how you should learn openings and how you eventually form a mindset for how to think about them in general such that you can even start developing your own systems for facing various things.


Could a top ranked GM draw against Stockfish using drawish opening lines in classical chess?

They can't. Engines are absurdly strong relative to humans these days, and Stockfish should be fully expected to beat top human GMs 10-0 without much trouble. In fact, they already have - and that's in spite of Komodo being several hundred elo weaker than Stockfish. Book lines with high draw rates don't matter: either the engine avoids it, or they play it and win anyway because when the human inevitably makes a mistake, the computer capitalizes.
Caveats:

The engine needs to be properly configured. Stockfish comes with a "contempt" setting that needs to be turned up. This makes the program avoid quick draws.
The other top engine right now, Leela, does not have a contempt setting. This means humans can indeed score draws against it (this was against AlphaZero, which is similar to Leela and probably weaker than the latest versions). However: humans still cannot beat Leela/AlphaZero.
The engine needs to run on reasonably strong hardware. These days engines will beat humans even on modest hardware, but if you try very very modest hardware such that the engine only manages to search a few thousand positions per second, humans might still win.

Edit: for the strategy you suggested, this was what happened when GM Michael Adams tried it against Hydra in 2005. Link to game if you want to see the moves.

Game four was another bitter pill for the human player. Adams, who had the white pieces, did everything he could to draw: exchange pieces to reduce material, simplifying in every way he could. By move 19 he had traded down to rooks and a bishop on either side; by move 27 each side had two rooks and five pawns; and at move 33 it was rook plus three pawns each. This one had to be a draw, but unfortunately the giant machine would have none of it and ground him down for a third victory in this match.

Hydra is, of course, very very inferior to the latest versions of Stockfish, and will probably lose a 100-game match by something approaching 0-100.


Computer evaluation is based on perfect play from both sides, which is never the case in human games, and hence is irrelevant here. Given the nature of the position and the time situation, it is crystal clear that Firouzja had the "psychological" advantage, which he could've converted had the game been continued smoothly. Playing with a rook and an unsafe king against the bishop pair under time pressure is a nightmare for every chess player. Maneuvering with the two bishops is much easier. All this, in addition to other factors such as Firouzja's tournament position, makes up the post-game controversy that has arisen.


Reading UCI Engine output in Arena Chess

http://www.chessforums.org/general-chess-discussion/9079-chess-engine-output.html

  It’s the “search depth.” It tells you how deep the search has gone.
  The value is in “ply” or half-moves. The first number gives you the
  “brute force” depth, the second is the depth to which certain critical
  lines have been investigated. For instance a display of “depth =
  12/30” means that the program has looked at every continuation to a
  depth of 12 ply (six moves), while some promising or dangerous
  continuations are being examined up to a depth of 30 ply (15 moves).

Please note chess engine always report in "ply", half-move.


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

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

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

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

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

[Title "BenOni"]
[fen ""]

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

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

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

[Title "BenOni"]
[fen ""]

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

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

Good luck on the tournament!


Truth is there isn't a lot out there for chess. The best I could find was this from the Ankiweb site - https://ankiweb.net/shared/info/1176122148 There aren't many free decks for chess but it does guide you into how to make your own which you can do using puzzles that you find and like in books and the web.

For getting started with Anki Alex Vermeer's site has some useful stuff - https://alexvermeer.com/anki-essentials/


What are Black's plans in this position from the Breyer defence?

After 17 Bxc5 Bxc5 18 ed Qxd5 no pawn is lost due to the mate threat at g2.
Black has two active bishops and threatens Rad8 with pressure on the d pawn. If white does not exchange pawns then black can play Qd7 and Rad8.


Strategic and tactical ideas for White in this KIA game

I had studied the KIA for a time in the early'90's, although with mixed results, so I don't claim to be an expert on the subject.  In this position 12.c3 would constrain the Black "d" pawn, but I think I would initially play 12.Bh3 to restrain the more important "e" pawn, which is currently backward on the open file.  Then if 12..., e5; 13.Bxc8 & 14.Nxe5 would win it. Or if Black decided to reinforce it by 12..., Nd8, then 13.Ne5 could occupy the hole and then support this N with subsequent 14. Ndf3 and 15.Bf4 moves.  And since the purpose of the KIA is a kingside attack, you would probably subsequently want to mobilize your kingside pawns once you had this center control.  I hope these suggestions are of some value.


Using Eye Drops (fake tears) can be useful when exceeding recommended screen time.
What also helps me is taking frequent breaks every hour and drinking plenty of water.


Does the pawn's initial double square move have a special name?

No, it's a standard move. By definition, pawns are pieces which can move 1 square forward or 2 on the first move, and can capture diagonally. These actions don't have special names as they're easy to define, but en passant requires a bit more explanation (as most pawns never do it in any particular game).


Who is Yuri Dojoian, Kasparov's analyst in the 90s?

I think the player you are referring to is Yury Dokhoian. According to his FIDE profile and Olimpbase profile he has not played competitive chess since 1994. According to his Wikipedia page he was Kasparov's second for many years and later started working with Karjakin. Chessgames.com has 173 of his games.


How to bring tactics skills into the actual play?

As you have noted yourself, an important difference between solving tactics and finding tactics during a game is that you know that there is something interesting when solving tactics. There are a couple other important differences.
In a game, it comes down to your ability to discern a critical position from an ordinary one that only requires positional consideration. In long time controls, it is advisable that you treat every position as a tactical puzzle, at least for some amount of time. Of course some positions you know are not critical, but spending a little bit of time checking every move will help you be more tactically aware. And of course, you got to watch out for your opponent's tricks too.
I will ignore the question relating to having a 2200 tactics compared to 1800 elo because the scale may be different between the two and an 1800 rated player could have a range of tactical ability anyways.


The Holy Grail of chess match footage! This question has been asked before on Reddit, on Chess.com and probably on many other websites and no one has come up with an answer.

There are many sources that claim that Chester Fox, an american businessman, had procured the filming rights for the match. According to an unsigned article on mark-weeks.com, "Fox sold the rights to the American television company ABC for 100.000 US$", apparently after the eighth game.

Another source of footage is Shelby Lyman's series of television programmes for PBS (Public Broadcasting Service). See, for example, The man behind the Fischer-Spassky show by Rudy Chelminski (Chessbase.com, 2003). It is not clear to me where he got his images (unless the programmes didn't use any footage that was shot during the games).

An article by Edward Winter about the match also contains a pointer to some coverage in the archives of AP (Associated Press), but these are mostly short news items and some footage from outside the playing hall.

So my best guess is that the footage is in the vaults of ABC and PBS.


How does a Class B chess player become Class A?

I recommend simply playing rapid games, or longer, and a post mortem analysis with computers and self analysis. Playing games against stronger players is desired if possible. I recommend starting to learn some opening theory and form a good repertoire. Whatever your opponents play, you should have a response that you enjoy. You say that you are good at playing closed games. I would rub against your wound here and advice you to play open games. Open games also helps on your tactics, which everyone will tell you is important.


Is it possible to fully analyse, at least some openings of chess?

The moment we knew that a variation would be winning for either White or Black, the other side would never go for that variation. E.g. after 1. g4 e5, White will never play 2. f3 because we know that variation is winning for Black.

But there are some openings which have been analyzed to a draw by repetition of moves, even before the computer era, e.g. the Greco variation of the main line (Giuoco Piano) of the Italian game:

[FEN ""]
1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. c3 Nf6 5. d4 exd4 6. cxd4 Bb4+ 7. Nc3 Nxe4 8. O-O Bxc3 9. d5 Bf6 10. Re1 Ne7 11. Rxe4 d6 12. Bg5 Bxg5 13. Nxg5 O-O 14. Nxh7 Kxh7 15. Qh5+ Kg8 16. Rh4 f5 17. Qh7+ Kf7 18. Rh6 Rg8 19. Re1 Qf8 20. Bb5 Rh8 21. Qxh8 gxh6 22. Qh7+ Kf6 23. Rxe7 Qxe7 24. Qxh6+ Kf7 25. Qh7+

Almost all deviations after move 8 or so have been proven either to draw as well, or to lead to a worse position.


What is the lowest possible rating you can achieve (if any)?

If the Elo system is implemented in its purest form, there is no theoretical lower limit for a rating.

Practically though, every chess organisation implements its rating system a bit differently and often there are rating floors that constitute the lowest possible rating.

The USCF for example seems to have a rating floor of 100.


How to play against bad bishop outside pawn chain

Two ideas that spring to my mind:

Harass the bishop, and threaten to trap it / exchange it for a knight, with moves like h3, g4 and Nh4.
Attack the squares/pawns the bishop has left behind, with moves like Qb3 targeting the b7 pawn, or Qa4 / Bb5 / Ne5 targeting the a4-e8 diagonal.


Are there consumer-level game play analysis systems that overlay the analysis on the board real-time?

I'm pretty sure Fritz has something like this, not to the extent of going as deep as the images you provided, but any potential patterns that it likes are represented graphically, using coloured arrows and squares, while analysing.

Example of Fritz visual output:

SOURCE: Visualize search in Fritz 10 (21.05.2007)


Free offline demonstration software with arrows, sidelines and engine

Did you already give Scid a really good look?
Drawing Arrows
Arrows can be drawn in two ways. In the Main Board, hold Control and click on the start square and then end square. Or in the Comment Editor arrows can be drawn (and erased) by dragging between two squares.
Of course there is Chessbase in many sorts and sizes. You're probably able to find an old version for free if you search well.
Hope this brings you a bit closer.


What is the shortest number of moves from the starting position required for Black to mate White with a pawn?

4 moves, as far as I can tell.

[FEN ""]
1. e3 e5 2. Ke2 Qh4 3. Kf3 d6 4. Qe2 e4#

Another one:

[FEN ""]
1. d3 d5 2. Kd2 e5 3. Kc3 Be6 4. Qd2 d4#

And one more:

[FEN ""]
1. e3 e5 2. Ke2 d5 3. Kd3 Qf6 4. Qe2 e4#

Same theme for all of them, really.


How to read score from stockfish - inconsistent response every call?

The reason is simple - hashing. The first time you run the analysis, the engine stored the computed positions in a hash-table. This table was not clear the next time you run the analysis. Next time, when you ran the same analysis, the engine could search further and thus returned a different score for it's principal variation.

Evidence? Note the node counts was: 1327846 for your first attempt and 4912037 for your second attempt. The NPS (nodes per second) was very close (1074309 vs 1040685). Clearly Stockfish used the existing hash-table to skip moves it had already computed in your first attempt.

Note that this is an expected behaviors, clearing hash-table after each move would dramatically reduce the engine strength.


As a Class B, how do I improve my chess against A level or higher?

Silman's How to reassess your chess book is invaluable. Give it a thorough reading if you haven't yet.

My advice would be

Replay your game with an engine. Find out the moves you did wrong.
if most are tactical, then train yourself on that
if most are positional, then find out what imbalances are there at your move. Read relevant chapter in the book (could be just the summary section) and see if you can find a better move.


[FEN "2Q1Q3/2Q4Q/Q4Q2/3k4/Q5Q1/1R6/B1NBQ3/K2R1N2 w - - 0 1"]

How many mates?
What was black's last move?
hint: this construction (by Anthony Stewart Mackay Dickens, published in The Problemist, Jan 1970) ties the record (set by Nenad Petrovic, Sahovski Vjesnika, 1947), using fewer units.
Happy counting. But, frankly, I doubt this is useful to you...
This is certainly a remarkable diagram from a constructionist perspective, but it was never intended to improve a player's vision (in fact, if anything, such a visualization exercise will lead to blindness).
Stronger players may solve this faster (the guy in the video offers no statistical analysis), but solving faster will not put us among them.
Personally, I doubt that such unnatural mates in one can be a useful training exercise to improve your "vision."
I have no doubt that solving simple combinations and mates (e.g., Polgar's 5334 puzzles book) -- until the common patterns become automatic -- will improve your tactical ability.
A diet of endgames is even better!
Reading miniature games without a board might be the best ways to benefit your visualization (and your opening repertoire).
Another good way to improve visualization is to attempt "word" problems without a board.
For example, consider this problem from Sam Loyd (which I will paraphrase below)...
You took a new job, and just relocated into the wilderness. Your chessboard and computer will not arrive for a week or so. Despite that, you just received a certified letter from your former boss, with whom you reluctantly agreed to keep in contact by way of a correspondence chess game. This arrive early, no doubt, with the intent to put you at some disadvantage. But, no worries -- you have three days to answer the opening move, and who needs a chessboard to answer the opening move?
In the letter, your former boss boasts of needing to make it challenging.
"I play 1. f3," he double-exclaims... and there's more... he also sends the following list of conditional moves: "if legal, I play 2. Kf2, 3. Kg3, and 4. Kh4."
Technically, you need only answer the first move within three days, but despite having no chessboard, you have a strong incentive to spare your cheap opponent the cost of another postage stamp.
Can you find a series of moves which checkmates your opponent on your fourth move?
It is possible, but to find it, you'll need to unlearn everything you know about chess.
Just remember: finding the solution is not the point -- the whole point is to search for mating ideas of your own, and visualize the positions (to confirm your ideas without shuffling wood).


How likely am I to beat a grandmaster through random play?

The chance is absolutely zero. Not just against grandmasters, but against anybody.

In fact, it would be hard to win a game with random play against someone actively trying to lose, after all you would just as likely remove your pieces from the vicinity of the opponent's king than play the checkmating move, if the opponent finally managed to get to a position where mate is possible.

Everybody who knows the rules and has some sort of goal in mind plays much better than random play.


It was illegal to move the queen here (and any piece in general) if that move put the king in check from another of the opponents pieces.

If the player tried to move the queen here they have to put it back and make a legal move.

Note that in some nonstandard variation most usually of the blitz speed type the special rules allow you to take the king and win if they make that illegal move.

Some other variations may allow claiming a win if an illegal move is made.  I have played blindfold games where that illegal move was a loss by the special rules for that variation of chess.


Unless you explicitly hard-code these endgames, or provide the computer with endgame tablebases, they will apply what they've always done throughout the game: search lines and return the static eval (which is basically the evaluation function of the engine, evaluated on the final position). The static eval isn't smart enough to realize that this game is a draw - keep in mind the static eval is supposed to work for all positions, so it's not surprising that it doesn't return a completely accurate score for this one. Accordingly the computer flatlines at -0.50, until the 50-move rule helps it prune to a draw.


Are there any inherent problems with point-symmetric random chess?

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

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

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

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

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

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


How to test the quality of an opening book?

EDIT: Answer to Revised Question Below

Based on the way you described it, it makes sense to simply open up the PGN along with any engine and go through it line by line. I do not believe there's an automated way to iterate through all the moves and ensure their individual accuracy.

I'm curious as to how you generated your book to begin with - did you do it with engine-assisted analysis? If so, that will affect the accuracy of your repertoire from its inception.

What I would do in your situation is manually compare the PGN file to moves that are popularly played. Useful resources are Shredder's free opening database as well as 365 chess opening explorer. Both are intuitively organized so that the most popular response is readily available.

Depending on the depth of your preparation, blunders can be present or not at all. I would double check this with an engine, such as the free Houdini 1.5 just to be sure.

As an aside, it might be a good idea to organize your opening database into separate PGN files dependent on ECO code. This makes it easier to navigate when you want to search through particular openings.

I hope this helps! If you have any follow-ups, feel free to reach out.


Why is 7...Ne4 8.Bd2 such a popular line in this variation of the Queen's Indian Defence?

White wants to avoid doubled c-pawns and all of the moves you mention, Qc2, Qd3, Nxe4 and Bd2 achieve this.

As you note, Nxe4, exchanging knights tends to be drawish, so is not what most white players want.

With the queen moves (Qc2, Qd3) your queen will end up on c3, which is a bit of an unusual square for the queen. Also the c1-bishop is not developed yet, so white would still have to connect his rooks and likely move the queen to a better square.

Bd2 is a modest development move for the bishop, but it does make space for the rooks. Also, if black takes Nxc3, Bxc3 and the bishop has found a very nice square on c3.

I would not be concerned about giving up the bishop pair. The black knight on e4 is a rather strong piece while the dark squared bishop is the weaker of white's bishops due to the pawn structure.


What is the highest number of different mates in 1 you can have in one (legal) position?

[FEN "1B1Q1Q2/2R5/pQ4QN/RB2k3/1Q5Q/N4Q2/K2Q4/6Q1 w - - 0 1 "]

105 mates — Nenad Petrovic, Sahovski Vjesnika 1947 (Chess Problem Database)

In this position any check is mate. There are 3 knight mates (c4, g4, f7), 23 discovered mates (14 moves for the rook on c7, 9 for the bishop on b5), and 79 queen mates: 1 on a1, 2 on b2, 3 on c3, 4 on c5, 6 on d4, 3 on d5, 6 on d6, 3 on e1, 2 on e2, 4 on e3, 4 on e4, 2 on e6, 4 on e7, 3 on e8, 5 on f4, 3  on f5, 6 on f6, 4 on g3, 5 on g5, 2 on g7, 3 on h2, 3 on h5, and 1 on h8, for a total of 105 mates.


What are the options for solving puzzles online and tracking progress?

ChessTempo allows for unlimited solving of tactics problems with a free membership. It has a large database of problems drawn from games, and it tracks your solving statistics along with your individual tactics rating. Also, you can track your progress on two sorts of problems: untimed, or where the elapsed time for solving factors into your performance rating.


Is there an engine which tries to find moves that forces the opponent to find the best move?

The short answer is no (as far as I know). You're adding together two concepts, so let me try to address them both:

Moves that have responses that are hard to find. This is a tough problem because it basically means running a regular computer engine and a more human-like engine at the same time, and seeing what moves are found by the first but not the second. People gave up on human-like engines a while ago because the more brute-force was so much more effective. So this is a tough research problem (one that people worked on for decades in the 20th century) without a big payoff.
Moves that are forcing. If the opponent has only one good response, that increases the chance that she'll play a bad move, right? Well, not really; if I play a capturing move and the only good move is a recapture, chances are my opponent will find it. So just using the number of good responses as a measure of how tricky a move is problematic. (Forcing moves are usually good to consider because they limit the search tree and increase the chance that all leaves in it are good for you, but that's a different reason from trying to induce a mistake.)

It would be nice to have an engine whose evaluations were "How likely would I be to win from this position against another 2000 player?" rather than "How likely would a computer be to win from this position against another computer?" but people have overwhelmingly concentrated on the later. (I would be delighted to be wrong about this.)


By far, ChessBase is the most popular one, it has been there for a long time. But there is other software that can do more or less what ChessBase can do, like Chess Assistant.

When you compare software, you should consider comparing for example Fritz vs. Hiarcs or ChessBase vs. Chess Assistant, because Fritz or Houdini or Rybka are mainly engines with the capability of full game analysis and ChessBase is more of a database with special feature for the pros.

In terms of opening encyclopedia or other products, they could be read with almost any professional chess software. So, no problem here.

Finally, if you are not a professional chess player, any software like Hiarcs, Shredder or even Stockfish with a GUI could help you and you don't need to buy such expensive software.


FIDE tournament rules: Does a player HAVE to record the opponent's move before making a move?

No, you don't have to. In rule 8.1 of the Laws of Chess, it says:

  A player may reply to his opponent’s move before recording it, if he so wishes. He must record his previous move before making another.

So your previous move must have been recorded by the time you make the next. You must have recorded at least 1.e4 before you can play 2.Nf3.


Illegal move or forfeit on time - who wins this 5-minute match?

When an illegal move is completed once the opponent’s clock has been started. The opponent is entitled to claim a win before he has made his own move. However, if the opponent cannot checkmate the player’s king by any possible series of legal moves, then the claimant is entitled to claim a draw before he has made his own move. Once the opponent has made his own move, an illegal move cannot be corrected unless mutually agreed without intervention of an arbiter.

As far as the time/check priorities go... As far as I'm aware(and in any tournament I have played in thus far) any player that is first to claim for a win will win the game, UNLESS both flags have fallen in which case it becomes a draw. It is part of the game(especially in blitz) for a player to be aware of the clock and there is no default loss when a player's time hits 0 unlike online chess where this is done automatically.

EDIT:

Since someone wanted a conclusive pointer to a rule that enforces this... which took a while it is found in the fide rulebook which can be found at http://www.fide.com/component/handbook/?id=124&view=article
There is also a short section regarding blitz(which is less than 15 minutes) which seems to handle the same format.


In general, it is not easy to develop rooks during the opening per se. Not only it's not easy, it rarely is a goal of the sound opening.

In some references, the opening ends, when minor pieces (bishops and knights) are developed and rooks are connected. Therefore, it is highly likely that you are already talking about the middlegame rather than the opening.

Now, regarding the general use of the rooks. Rooks are good at open files (or files that are likely to become open). Instead of having the goal of using rooks to defend the two middle pawns, I suggest looking for good files for the rooks, whether it is in the center, open C-file, or, soon-to-be-open A-file.

To get the best of your opening (again, there are always exceptions, established theory) in general, look at developing your minor pieces at active squares, castle your king, connect the rooks, and place them at strategically promising files.


Why does ChessMaster recommend 24. Rg3 in this position?

All of White's other pieces are placed well except the Bishop on f3.  If Black moved the a8 rook back and forth then White would probably like to play Rg3, Bg2-h3, and maybe Rg3-e3.
Simply put Rg3 increases the scope of the rook and the bishop.


Black would like to continue their development with Nf6 and castling short. g4 discourages Nf6; after g5, the knight is forced back. It also prepares Bg2, which protects d5 without giving up the pin on the e-file. The weakening of the kingside apparently isn't too much of a problem; Black isn't developed enough to take advantage of this, and White can always castle queenside.


Where can I find these mentioned chess problems?

Henrik Juel's three "add pieces" problems listed above (together with a fourth one) are all to be found, together with detailed solutions in PDB, using the query: a='juel' and K='add pieces'.
Here is the superb fourth one, with its surprising solution...
[Title "Henrik Juel. Probleemblad, 5/1997. Add a unit. What was the last move?"]
[FEN "4k3/ppp1pp2/4pp2/8/3P4/3P2P1/1PpP1PP1/2K5 w - - 0 1"]


What are the origins of the words 'zwischenzug' and 'zugzwang'?

Chess historian Edward Winter has a page listing the earliest known occurrences of various chess terms in English, relying mostly on citations from the OED, though for these two terms he has slight improvements on those. For Zwischenzug the earliest known use is in Chess Strategy and Tactics, by Fred Reinfeld and Irving Chernev from 1933. For Zugzwang the earliest known use is in the February 1905 issue of Lasker's Chess Magazine.

As to why these terms caught on in English, I'd say the main factor, at least for Zugzwang, is that German is good at packing a lot of meaning into a single compound word in ways that English isn't. In fact, though Zugzwang was used as early as 1905 in English, Winter indicates in another article specifically on Zugzwang that usage of that term wasn't common in English chess literature until the appearance of the English translation of Nimzowitsch's My System. He notes that the translator, Philip Hereford, wrote in his introduction that Zugzwang was the only word he left untranslated

  "mainly, because the single word conveys an idea, or complex of ideas, which can only be expressed in English by a circumlocution."

Sure enough, if you try to think of another way to say "Player A is in Zugzwang," you do find yourself needing to be much wordier, like "Player A is compelled to move, to his own disadvantage."

The same reason doesn't seem as important for Zwischenzug though, as it's no easier to call something a Zwischenzug than to call it an "in-between move," the literal translation of the term. I don't know, sometimes language is funny I guess.

Speculative update: Here's an off-the-wall guess. As Winter notes, the first use of Zwischenzug in English was in 1933. And he also thinks that the English edition of My System, which was shortly before in 1929, is what brought the use of Zugzwang into widespread use. So maybe that simply made it "fashionable" at the time to use a similar term like Zwischenzug as well. Chess players are already sort of like that, with openings coming into and out of fashion over time.


Are there any other endgame analysis tool than Wilhelm?

Finalgen (http://finalgenchess.ovh/home_ing.php) generates database for positions with kings, one piece each, and any number of pawns. It has it's disadvantages, but it's free.


Here are a very few principles which are key:

Centralize/activate/use your king. In the endgame he is one of your strongest pieces, and needs to be utilized.
When you have the advantage, exchange pieces, and don't exchange pawns. Every exchange of pawns means one less potential promotion for the side with the advantage.
Passed pawns must be pushed, and outside passers are the best. An outside passed pawn can be the most distracting to an opponent's king or other pieces, keeping them out of other action.
Principle of 2 Weaknesses. One of the best way to convert an advantage into a win is to use it to induce another problem in the opponent's position, when he or she will then be forced to fight a war on two fronts. (For instance, this can be why an outside passer is so strong: while the opponent deals with it, a second weakness can be created and exploited on the other side of the board.)
Do not hurry! Here are some words from Shereshevsky, coming from his chapter with this title in his classic Endgame Strategy:

  How many endings have not been won, merely because the stronger side tried to win as quickly as possible, and neglected to make simple strengthening moves before embarking on positive action. Following the principle of "do not hurry", it is possible to battle for a win in positions with a slight but persistent advantage. ... The logic behind the "do not hurry" principle is mainly psychological. It can be especially recommended to act according to this principle when the opponent is deprived of active counterplay.

  Plenty more such principles can be formulated of course. These are just a few very general ones that can apply in most any endgame.

One book along the lines of your question that I cannot recommend highly enough is Rate Your Endgame by Edmar Mednis and Colin Crouch (based on Mednis' earlier Practical Endgame Lessons). It's now out of print, but if you can find a used copy, grab it. It offers its own explanation of endgame principles, and illustrates them with many examples, which are presented in a "test your play" format, where you are prompted to play one side of an ending from actual play. I got this book early on when I started "really" playing chess, and remember loving it, and learning a good deal. It is very much a general manual on how to approach the endgame, rather than being a discussion of various theoretical positions/endings. I've never read a poor opinion of this book, and when someone like Mark Dvoretsky gives something praise, it's not to be ignored.


What's a really good tactic trainer rating on chess.com for a Candidate Master?

While you cannot get to Candidate Master on tactics alone, most Candidate Masters have much higher tactics trainers ratings than you do. For example, Candidate Master Mago has a TT rating of 2602. While you should continue on your TT journey, you should also study master games, endgames, and positional play.


Time/PLY to let engine run for opening analysis

How many PLY do you recommend to let the engine run on a single move

This will depend on many factors such as the actual position, how you use the engine for opening analysis, etc

If the engine gives a decent advantage (let's say +-2 or so), there is usually not much point in having it calculate down to mate. Other than that opening analysis with an engine is tricky and should certainly not be automated. Engines are useful for pointing out tactical mistakes in openings and can be useful in evaluating midgame/endgame positions that result from some opening lines.

However at least currently you cannot expect engines to give you the absolute best line from say move 5 in any opening. In many openings engines give an evaluation of +0.6 or so even though experience shows that positions are perfectly playable for both sides.

Also human interaction is needed to evaluate how playable the position is for a human: e.g. you might have an equal position where you are required to find 10 only moves or so; this is not what you want to get into.

  How long does it take you time-wise to reach this?

Depends on position, computing power and perhaps other factors.


Why Is Black forced to give up the queen in this puzzle?

If black plays 1... Kf8 he will get mated. Here is one possible line given by the engine:
[FEN "1r4k1/3q3p/p2P2r1/4pNNQ/5p1P/P7/6PK/8 w - - 0 1"]

1. Ne7+ Kf8 2. Nxh7+ Ke8 3. Nf6+ Kf8 4. Nxd7+ Ke8 5. Nxe5 f3 6. Qxg6+ Kf8 7. Qg8#

You can answer questions like that by using an engine, for example here (click on the button "Toggle local evaluation" in the top right). There you can also check all other variants, which you can't figure out on your own.


Is there a chess engine that allows you to specify which opening it uses?

A great way of practicing your opening with a chess engine can be found on chess.com. You can create a free account, then go to the Learn Tab -> Book Openings -> Find the opening you want to practice -> Play Opening vs. Computer. You also have the chance to change the computer's difficulty level and what side you play.


I'd argue the process you're talking about can be represented by Markov Chain. It solves the continuous problem raised by @Brian.

I don't know where to find a proper state diagram for your question.The following diagram is for a simple board game. Imagine we model the transition probability from win to lose (or win to draw) as the blunder probability, this is similar to what you are asking.

We can represent "local minimum" described in your question as an absorbing state.

More generally, if you want to assume some latent factors for making a blunder (e.g. bad opening, personal issues), you could generalize to hidden markov model. It's possible to use the EM algorithm to fit a model from engine PV evaluations.

Given a fitted model, you can query the probability of a blunder given a chess game.

  Have there been any studies on chess using such model?

No studies that I am aware of.


Chess endgame database+50-move rule=potential error?

You are right that tablebases do not automatically contain information pertaining the fifty move rule.

To use tablebases accurately currently engines use the DTZ50 metric (distance to zeroing with fifty move rule) which tells you the number of winning moves until the 50-move count is reset. If this number is too big, the position is evaluated as a draw. Apparently this metric can give results that are one ply off.

To get perfectly accurate results these guys recompute tablebases with the fifty-move rule in mind. The resulting metric would be called DTM50 (distance to mate with fifty move rule). One of the differences between DTM50 and normal tablebases is that the winning line depends on the ply count and not only on the position on the board. Generally the higher the ply count, the longer the winning line, because a zeroing move has to be found within the next few moves, which restricts the possibilities. Here, you'll find an article about DTM50.


Yes or no: should a 'reverse' Ruy Lopez be played as black?

I think that this question comes from a fundamental misunderstanding that many beginners have but more experienced players don't even notice, which I wrote about in this answer.

The short version is that openings describe moves made by both players, not by one player. The Ruy Lopez is 1.e4 e5 2.Nf3 Nc6 3.Bb5, not "1.e4, then 2.Nf3, then 3.Bb5".

Given this, there is no real way to "play the Ruy Lopez as Black", since you're a move behind. The only theoretical way you could get to that position is something like 1.e3 e5 2.e4 Nf6 3.Nc3 Bb4, which would never happen.

...Bb4 mostly makes sense when 1) there is a knight on c3 and you want to undermine its support of e4 and d5, or 2) by checking you can force White to interpose a piece or pawn in an awkward way. These situations do come up but none of them are a "Ruy Lopez as Black".


Where to find specific endgame practice exercises/puzzles/practice bots?

If you're looking for a truly random position, I'd just roll an eight-sided die a couple of times to determine the column and row of each piece. (If the position is illegal, just reroll.) You can then enter the position into a chess program and play against the engine. Here's an online dice roller in case you don't have physical ones, the one you're looking for is called the d8.

If you're looking to practice key positions in KRP vs. KR specifically, you'd probably be interested in John Nunn's Secrets of Rook Endings. I forgot how this book is organized exactly, but it contains almost all positions in this ending which are worth studying.


can I force a draw if I am running out of time?

Of course! Just swap the queen for the rook.

There are two basic possibilities.

He keeps the king and rook very close (normal best practice when trying to draw this difficult endgame). In that case every time you threaten the rook with your queen he must move the rook and keep it close to the king. It should be easy to then skewer the king against the rook with a check or pin the rook against the king. This probably won't happen immediately but if you know what you are aiming for your opponent will find it very difficult to avoid for long, particularly since he also needs to avoid losing.
He keeps the rook and king well separated. This is fatal. The rook quickly falls to a fork.


You can do this on your own in a customized fashion (i.e. you control when to run the engine or to use the book) with a bit of scripting in python, using the python-chess module and a polyglot opening book of your choice. In this example I'm using gm2001.bin, which you can get from here.

As dummy example I have chosen two positions:

fen = 'rnbqkb1r/ppp1pppp/5n2/3p4/3P4/5NP1/PPP1PP1P/RNBQKB1R b KQkq - 0 3' A basic Catalan position for which I know the book still has a move.
fen2 = 'rnbqkb1r/ppp1ppp1/5n2/3p3p/3P4/5NP1/PPP1PP1P/RNBQKB1R w KQkq - 0 4' A position for which there are no book moves left in the chosen opening book.

What the code does is very basic: if it finds an opening move, then it makes that move (if there are more opening branches, you need to figure out how you want to choose the line to play), otherwise, it calls Stockfish with 10 seconds of movetime and makes the top engine move.

import chess
import chess.uci
import chess.polyglot

fen = 'rnbqkb1r/ppp1pppp/5n2/3p4/3P4/5NP1/PPP1PP1P/RNBQKB1R b KQkq - 0 3'
fen2 = 'rnbqkb1r/ppp1ppp1/5n2/3p3p/3P4/5NP1/PPP1PP1P/RNBQKB1R w KQkq - 0 4'
board = chess.Board(fen)
print board

handler = chess.uci.InfoHandler()
engine = chess.uci.popen_engine('stockfish_8_x64') #Provide correct address to where your engine is stored
evaltime = 10000

reader = chess.polyglot.open_reader('gm2001.bin') #Provide correct address to where your bin file is stored
n = sum(1 for _ in reader.find_all(board))

if n==0:
    print 'empty, using SF top move with 10 sec movetime'
    engine.info_handlers.append(handler)
    if board.is_checkmate():
        print 'Game has ended: checkmate'
    else:
        engine.position(board)
        eval = engine.go(movetime=evaltime)
        nextmove = board.san(eval[0])
        if handler.info["score"][1].cp != None:
            print 'Top move: ', nextmove, ' Evaluation: ',round(handler.info["score"][1].cp/100.0,2)
        else:
            print nextmove
        print board.variation_san(handler.info["pv"][1])
        print 'nodes: ', handler.info["nodes"], ' depth: ', handler.info["depth"], ' time: ', handler.info["time"]
        board.push_san(nextmove)
        print '---- Updated position:'
        print board
else:
    for entry in reader.find_all(board):
        print 'Found book moves:'
        nextmove = board.san(entry.move())
        print str(nextmove)
        board.push_san(nextmove)
        print '---- Updated position:'
        print board
        break

Output for the first fen:

r n b q k b . r
p p p . p p p p
. . . . . n . .
. . . p . . . .
. . . P . . . .
. . . . . N P .
P P P . P P . P
R N B Q K B . R
Found book moves:
c6
---- Updated position:
r n b q k b . r
p p . . p p p p
. . p . . n . .
. . . p . . . .
. . . P . . . .
. . . . . N P .
P P P . P P . P
R N B Q K B . R

and output for the 2nd fen (fen2):

r n b q k b . r
p p p . p p p .
. . . . . n . .
. . . p . . . p
. . . P . . . .
. . . . . N P .
P P P . P P . P
R N B Q K B . R
empty, using SF top move with 10 sec movetime
Top move:  Bg2  Evaluation:  0.24
4. Bg2 c5 5. c4 cxd4 6. cxd5 Qxd5 7. Qxd4 Nc6 8. Qxd5 Nxd5 9. Bd2 Ndb4 10. Na3 Be6 11. Ng5 Bd5 12. Bxd5 Nxd5 13. e4 Ndb4 14. Nb5 Nd3+ 15. Ke2
nodes:  14946976  depth:  21  time:  10001
---- Updated position:
r n b q k b . r
p p p . p p p .
. . . . . n . .
. . . p . . . p
. . . P . . . .
. . . . . N P .
P P P . P P B P
R N B Q K . . R

You should be able to take it from here and extend the code however you want.


Is there a site where I can play 30 seconds games?

Not only does lichess.org has the option to berserk in 1m bullet-games, but after a recent update you are able to to start a 30sec game. You will learn nothing though.


Why is pawn c6 is not winning here and what is the missed win for black?

Look at the diagram. The engine tells you the best move (Rd8).

The idea behind that move is that it pins the white knight to the queen and at the same time attacks the knight a second time.

Moving the knight white would lose the queen (for a rook).
If white tries to defend the knight (with c4, Bc4 or Bf3), black would play c6 attacking the pinned knight with a pawn.

So the idea is: first pin, then win the knight with c6.

If you play c6 first, white could just retreat the knight to c3.

It is worth memorizing this theme (pin a piece, then attack it again) as it is quite common. Also works with diagonal pins by queen/bishop.