Why do players attack one apparently unimportant square?

I can't answer your question in general, but I can explain the main ideas of the game.  Here is the game (actually the game lasted a few more moves, but at the end position here it is lost for Short):

[FEN ""]

1. e4 e6 2. d4 d5 3. Nd2 c5 4. Ngf3 Nf6 5. exd5 exd5 6. Bb5+ Bd7 7. Bxd7+ Nbxd7 8. O-O Be7 9. Re1 O-O 10. Nf1 Re8 11. dxc5 Nxc5 12. Be3 a6 13. c3 Rc8 14. Qc2 Qc7 15. Rad1 b5 16. Bd4 Nce4 17. Ne3 Rcd8 18. a3 Bf8 19. Qb3 Qc6 20. Ne5 Qc7 21. Nd3 Bd6 22. g3 Qc8 23. Bxf6 Nxf6 24. Nb4 Bxb4 25. axb4 h6 26. Rd4 Re5 27.Red1 Qh3 28. Qc2 Rde8 29. Rh4 Qe6 30. Rhd4 Qh3 31. Rh4 Qe6 32. Qd3 Kf8 33. Rd4 Qh3 34. Qf1 Qe6 35. R1d3 Re4 36. Qd1 Rxd4 37. Rxd4 Rd8 38. Kg2 Rd7 39. Qd3 g6 40. h3 Kg7 41. Qd1 h5 42. Qf3 Ne4 43. Nxd5 Ng5 44. Nf4 Qb6 45. Qd3 Qc6+ 46. f3 Rxd4 47. Qxd4+ Kh7 48. Qd5 Qf6 49. h4 Ne6 50. Nxe6 fxe6 51. Qb7+ Kh6 52. Qxa6 Qe5 53. Qb6 Qe2+ 54. Qf2 Qd1 55. Qe3+ Kg7 56. Kf2 Qh1 57. Qxe6 Qh2+ 58. Ke3 Qxg3 59. Qe7+ Kg8 60. Qg5 Qe1+ 61. Kd4 Kf7 62. Kc5 Qf2+ 63. Kxb5 Qxf3 64. c4

Opening

Take a look at the position after Black's 16th move.  The opening phase is over.  It is a typical isolated queen's pawn position.  Here Kasparov has a better pawn structure as his pawns are in two pawn islands as opposed to Short's three pawn islands.  Why does that matter?  A pawn island is pawns that can defend each other.  As you will see the only pawn on the board that can't be protected by another pawn (except after an exchange) is the d5 pawn.

As compensation for this tiny disadvantage black normally gets more active pieces.  As you can see Short has good pieces here.  If Kasparov can manage to get Short on the defence then this compensation (active pieces) will disappear.  This might not be much, but at the top level any kind of advantage is better than none.

Why can't Kasparov attack Short's king instead, or some other piece?  Well, any piece can always move (but remember that the d5 pawn cannot move) and since Short has more active pieces any direct attack will fail.

Moves 17-25

What did Kasparov gain from attacking the pawn here?  Well, he forced Short to give up his bishop against a knight.  A bishop is considered slightly stronger than a knight, in particular in positions with pawns on both wings.

Still the d5 pawn is the easiest target to attack, although now the a6 pawn has become weak as well.  It would be dangerous to attack this pawn though, as doubling rooks on the a file would leave the white king less well protected.  This is something Short would have loved as it could have given him a strong counter attack.

Moved 26-35

During this phase Short tactically defended the d5 pawn by putting his queen on h3.  Should Kasparov take the d5 pawn it would have let to a mating attack for black after rook to e1.

Moves 36-41

Still the d5 pawn is the only real weakness in Short's position.  It still cannot move and should it drop the endgame is very difficult for Short.  The plan for White would then simply to be to exchange all the pieces and win the pawn endgame.  That would not necessarily be easy, but would give Kasparov an easy plan.

Moves 42 and out

Finally, on move 42 Short blunders tactically and loses the d5 pawn.  Now the game changes character.  Kasparov tried his best to exchange pieces while Short tries his best to avoid trading pieces.  Short's best hope here is to trade pawns, hoping for a draw.  Notice how Short avoids trading queens.

I only found the score up to move 64.  Short played on, but finally he surrendered when he realised that Kasparov would get another queen by promoting the b pawn.

Conclusion

The pressure on the d5 square led to Short finally blundering the pawn.  Had he not the game might have ended in a draw.  Of course, there are other plans, but you have to pick one.  Kasparov looked for the point in Short's position where he could attack and found it on d5 as the pawn could hardly move without being lost and could not be protected by another pawn.

Really strong players will find small ideas like that.  Kasparov did not necessarily expect to win the pawn, but at least to force Short on the defence.  If everything else is equal, having the more aggressive position is an advantage. Although it could be small, it is better than nothing.


Which book should one read if they want to play like Tigran Petrosian?

One of Petrosian's greatest strengths was his prophylactic thinking; i.e., identifying threats before they arise and neutralizing them. A book which discusses this concept would be good. For example, "Recognizing Your Opponent's Resources: Developing Preventive Thinking".

If you want to learn more about Petrosian himself, part 3 of Kasparov's My Great Predecessors series would be good. In this book he goes over the games of Spassky and Petrosian.


Can anyone recommend a positional book focused on preparing pawn breaks?

@Marcelo, it really depends on what you mean by "preparing".

If you mean that VERY specifically "what specific moves" in every case, that is too general, and there are no such books. If you mean that as "how do I play for a pawn break", in general, then you are really just asking about pawn play, and pawn structures.

Here is a fairly complete list of books about opening pawn structures and pawn play, in general.

"Chess Structures: A Grandmaster Guide" by GM Mauricio Flores Rios is the single best book on OPENING pawn structures currently out there, but it misses some.
"Pawn Structure Chess" by GM Andy Soltis is VERY weak in the analysis, but the general ideas still hold up.
"The Ideas Behind the Chess Openings, Algebraic Edition" by GM Reuben Fine
"Chess Opening Essentials" by New in Chess Four Volumes cover every opening, but each one is done fairly lightly, so this is a true beginner's guide.

Here is a list of books on general pawn play.

“Complete Chess Strategy” volumes 1,2 and 3 by Ludek Pachman. (This teaches about many basic plans, and what you are striving for with your pieces and pawns, especially. This made a light go off in my head, and THIS is what made me a master.)
"Winning Pawn Structures" by GM Alexander Baburin
"Understanding Pawn Play" in Chess by GM Drazen Marovic
"Dynamic Pawn Play in Chess" by GM Drazen Marovic
"Winning Chess Middlegames: An Essential Guide to Pawn Structure" by GM Ivan Sokolov
"Chess Middlegame Strategies Volume 2" by GM Ivan Sokolov
"The Power of Pawns: Chess Structure Fundamentals for Post-beginners" by GM Jörg Hickl
"Isolani Strategy: Strengths and Weaknesses of the Isolated Queen's Pawn" by GMs Adrian Mikhalchishin, Alexander Beliavsky, Oleg Stetsko
"Understanding Maroczy Structures" by GMs Adrian Mikhalchishin and Georg Mohr
And the original book on the subject, but it uses some weird terms: "Pawn Power" by IM Hans Kmoch


What are the rapid and blitz forms of chess?

Rapid and Blitz are both form of fast chess

Rapid, as the name suggests, is a faster version of chess

Time controls for each player in a game of rapid chess are, according to FIDE, more than 10 minutes, but less than 60 minutes. Rapid chess can be played with or without time increments for each move.

Many tournaments with a large player count opt for this faster format to try and finish off an entire tournament in a day or two.

Blitz is even faster than rapid, with times less then 10 minutes on the clock.

Time controls for each player in a game of blitz chess are, according to FIDE, 10 minutes or less per player. This can be played with or without an increment or delay per move—a more recent development due to the influx of digital clocks.

Both these formats have their own rating category in FIDE in 15+10 and 3+2 time control respectively.
Source:Wikipedia


Castling is generally a good move because it gets your king out of the center in the early and mid game. The center is contested in the early and middle game. The classical idea behind controlling the center is that with more space to place pieces and maneuver, that player has a positional advantage that can transform into a tactical advantage if their opponent plays imprecisely. Getting the king away from tactics and scary pieces is a good way to avoid getting checkmated.  Once those scary pieces have been traded off, the king is best placed in the center where it is often the most powerful piece of the endgame.
It's true that the king is easier to checkmate in the corner, but the king is also easier to defend in the corner.


How to search for a particular opening on the Internet

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

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

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


Defensive strategy relying on a wall of pawns

I would say that type of formation leaves a lot of weak squares, as enemy pieces can occupy pretty much any dark square they want (mainly b4, d4, f4, h4) and start an attack from there with help from the pawns. These pieces will never ever be kicked away. White's light squared-bishop will also suffer because he has nowhere to go, so, for that strategy to be effective:

White needs to have traded his light-squared bishop beforehand, or else pretty much any bishop vs knight endgame will be lost.
White must keep his dark-squared bishop at all cost, or else Black's bishop could be very harmful
White needs to know what to do about enemy knights on f4 and d4.
Pawn breakthroughs near White's king must somehow be prevented (for example, if Black castles in the kingside, ...h7-h5 must be somehow prevented)

In short, I don't like that kind of "wall" at all. And we haven't even talked about the at least eight moves it requires to build it, in which you can develop pretty much all of your pieces. Sometimes a c3-d4-e3-f4 formation is built (Stonewall Dutch), but this is only four moves and only leaves one weak square (e4) rather than four. So, occupy the dark squares, open a file and checkmate your opponent! If you want, post an example game where you've struggled against the "wall", and we can see what else could have being played


In the Ruy Lopez White usually wants to play with c3 and d4 to claim the center. If you play d3 instead then you lose a tempo if you still want to go for that plan.
Of course it is not the only possible plan but then the question becomes, if you answer 3...Nf6 with 4.d3, why would you not play the Italian instead where you might get a similar structure after for instance 3.Bc4 Bc5 4.c3 Nf6 5.d3, but arguably keep a bit more flexibility.
Still, 4.d3 against the Berlin is a fine way to play, it just doesn't have a clear benefit over other similar setups.


Why is the king powerless and the queen powerful?

Practically speaking, if the king were any more powerful, checkmate or capture would be impossible.

The Queen originated as the Advisor.  The Advisor was powerful, but not as powerful as the modern Queen, however.  Why did the Advisor become the Queen?  Having more than one Queen per side would debase the game, and there are two each of the other pieces.  Thus, the Advisor is the only candidate.

Why is there a piece with huge Queen-like powers at all?  It looks like the Europeans wanted to speed the game up.  So they made a more powerful Queen, pawns started moving 2 squares on the first, and castling was created.

Finally, I am not sure that the piece we call the Queen is called that in other languages.  The game and its ancestors have piece names like camel, elephant, advisor, minister, horse, etc.


How to use engines to improve my game (weak amateur, not a top player)

It's super hard to get better using chess engine. Those are only tools to help you verify if your calculation is okay. So let's say:

You can check if you saw all the variations that may happen after your sacrifice
You can verify if you calculated that pawn endgame correctly
You can also analyze your games

BUT... (!)

Do not use engines if you want to improve. I swear. The best way, in my opinion (and not only mine) is to analyze your game YOURSELF.

Then, you need to draw conclusions. Then you'll know what you need to work on the most.

Endgames
Openings
Calculation

Some great player (don't recall who) said you can learn the most out of endgames. But it really depends how advanced you are, i.e. if you are a beginner - don't spend your time on openings too much. We would need to know more information to help you better.


What is a tabiya and what is their importance?

"Tabiya" is a word that came from Sanskrit and passed into Old Persian, and then to our languages. It means "battle array".

The ancestors of chess, shatranj e chaturanga, had pieces with very slow movement (for example, our "Queen", at that time called General or Advisor, could move only one square diagonally). For this reason, the opening phase of a game could be very boring, since each player had to develop pieces without really attacking the opponent. The "real" game started only when both players had pieces "close enough" to begin the battle. This "close enough" situation was called tabiya.

During the centuries, some variants of the game evolved in different ways. One lead to the "chess" we know nowadays. Another lead to some variants of Thai Chess, for example, where players use pieces with very slow movement like the original ones, but start playing directly from some well defined tabiyas and not from a standard "starting position".


What is the longest known stalemate your opponent in x-moves problem?

The following thirty five move position is the longest position I could create.

White basically checks with four knights on c2 before blocking the black pawns with the king and knight on h1 while keeping the black king boxed in on a1. I tried extending this by adding another white knight on a3 to check on c2 but a black queen or black bishop cannot be added to capture on c2 since black still has eight pawns and there would be no square to place a black knight on to capture on c2.

[FEN "8/p1p2p1p/5pbp/8/qN1N4/4N2p/pr1r4/k1K1N2N w - - 0 1"]

  1. Nbc2 Bc2 2. N4c2 Rbc2 3. N3c2 Rc2 4. Nc2 Qc2 5. Kc2 h2 6. Nf2 h5 7. Nh1 h4 8. Nf2 h3 9. Nh1 h6 10. Nf2 h5 11. Nh1 h4 12. Nf2 f5 13. Nh1 f4 14. Nf2 f3 15. Nh1 f6 16. Nf2 f5 17. Nh1 f4 18. Nf2 a6 19. Nh1 a5 20. Nf2 a4 21. Nh1 a3 22. Nf2 c6 23. Nh1 c5 24. Nf2 c4 25. Nh1 c3 26. Nf2 h1=Q 27. Nh1 h2 28. Nf2 h3 29. Nh1 f2 30. Nf2 f3 31. Nh1 f2 32. Nf2 h1=Q 33. Nh1 h2 34. Nf2 h1=Q 35. Nh1


Setting DGT North American clock for two time controls

You can almost do what you're describing with this clock.

In actuality, it is better to NOT add time after move 40, but instead add the extra hour after one side's clock runs to 0:00.  This is because it is fairly common for the wrong side to start (i.e. time would be added after black's 39th move) or for the clock to be pressed an extra time which would result in time being added after white's 39th move.  This is problematic because now the clock says that you have, for example, 61 minutes left when in reality you would only have a minute to make your move.

So with that intro, it is very easy to setup the clock with two time controls and a 10 second delay.  As described above, the extra hour is added after the time first goes to 0:00.  A small flag icon is displayed and the clock continues counting down from 59:59.

In order to set the clock this way, you would use preset 23.  (Turn the clock off then back on and press the + button or - button until 23 is displayed)

After selecting preset 23, set the main time for the first time control to 2:00:00 on the first screen.  Then the clock will display 1 | 0.00 with the word "delay" in small print underneath the time.  This is the delay for the first time control.  Set this to 0.10 for a 10 second delay.

Now simply repeat these steps for the second (and possibly third) time control and you're ready to play.

One last caveat, before you start the game (by pressing the play/pause button), make sure that white's side of the clock is raised by pressing black's side.  Most clocks can be started by simply pressing black's clock at the start of the game, but this clock needs to be unpaused in order to begin.


Unable to confirm theoretical evaluation

For a Computer, White is Better.  For a Human, it's unclear.
White has quite a few advantages here - notably more space and superior development.  Black has one major advantage, though.  White's king is exposed and shall remain so for quite some time.
Computers excel at positions in which perfect defensive play is required - that is, positions such as White has here.  A computer will almost certainly see and defuse the various tactical threats to the White king, and eventually the computer should be able to convert the many advantages White has into something concrete.  But a human playing White is quite likely to err and allow Black the chance to make an effective attack.  Some humans will prefer to take on the Black pieces, on the premise that if they play aggressively White will eventually slip.  Other humans will prefer White.  Thus, we say that the position is "unclear".


How can I open (or convert into .PGN) old Chessmaster .CMG files, without Chessmaster?

To access them today, you either need to reverse engineer the format (hard) or export them to PGN inside Chessmaster (moderate):

  HOW TO CONVERT CHESSMASTER GAME FILES (*.CMG) TO *.PGN FILES

  (*.CMG files or Chessmaster game files are typically for use with the
  Chessmaster programs and may contain various enhancements, such as
  annotations, illustrated voice analyses, etc. Cf. page 25 of the
  Chessmaster 9000 user manual.)

  Log in (on Chessmaster 9000) and go to Game Room.
  Click on "File" in upper menu bar and then on "Load" in pull- down menu, to get "File Open" window.
  By default, the "Look in" box will show a folder that is named the same as the name you log in with. Let's say it is "Loginame." If the
  file you wish to convert is not in the list in the big box below, then
  you will have to find it by scrolling to other folders. In front of
  the file the little icon will contain the number 9000. (The icons for
  *.PGN files contain the initials PGN.)
  Click on the name of the *.CMG file that you wish to convert. The name will show in the "File name" box below. The "File of type" box
  should mention Chessmaster files. Leave "Auto" in the last ("Open as")
  box. Click the "Load" button and get the game on the board.
  Click on "File" and then on "Save" in the pull-down menu.
  "File Save" window comes up next. Check that the "Save in" folder is acceptable. (Your "Loginame" folder is OK, but you could even
  scroll to save the file on the floppy in drive a:) In the "File name"
  box below you can fill in a shorter (8-character) name of your choice,
  rather than accepting the long name created by Windows. In the "Save
  as type" box at the bottom,scroll and pick "PGN Game Files (*.PGN).
  Click on the "Save" button. In the "Annotation Type" window that comes
  up next, accept "None" by clicking "OK."
  The *.CMG file has been stripped to the plain *.PGN format and saved in the folder that you have chosen. If you wish to add this file
  to a database of your choice, see our earlier instructions under the
  appropriate heading.

Obviously, if you don't have Chessmaster installed, you will need to do that.  Easiest way might be to install a Windows VM, then install a legacy copy of Chessmaster.


Let's stick to one color, white here, and everything we'll say will generally hold true for black as well.

Rule of thumb: On the one hand, you generally don't want to move your king-side pawns (such as h3) when you've castled short, unless you have to, and we will expand on what "have to" entails here. The immediate exception to that is when you decide to fianchetto your king-side bishop, e.g., in the Catalan where then you play g3. On the other hand, your queen-side pawns (assuming you've castled short) are to be used more actively to either gain space or prevent an spatial expansion by your opponent.  (the rule is naturally to be taken with caution, chess rarely lends itself to these kinds of generalizations)

The more common cases are when a bishop is pinning your knight on g4 and h3 is an immediate way to try and challenge the bishop, asking it where it wants to go. But there are cases where g4 is not being exploited for a pin but rather as an intermediate square to re-route a knight (to e5 for instance). In either case, if the pin is problematic to deal with, which may be so if you've already made a commitment with your light square bishop and it cannot return to e2, or if the knight re-routing would be an improvement for your  opponent, then you really want to play h3 in a prophylactic way to prevent all of that. Here's an example in the Benko gambit:

 [Title "Benko gambit declined - preventive example"]
 [fen ""]

 1.d4 Nf6 2.c4 c5 3.d5 b5 4.Nf3 g6 5.Qc2 Bg7 6.e4 d6 7.h3 {Stopping any future knight re-routes to e5 via g4, and specially securing e3 for the c1 bishop. Bg4 is altogether less of a concern here in comparison}

And below you find two prophylactic examples of a3 and h3 where they are purely strategic and intentional:

 [title "a) Nimzo-Indian b)London system - (deliberate examples)"]
 [fen ""]

 1.d4 Nf6 (1...d5 2.Nf3 Nf6 3.Bf4 e6 4.e3 Be7 5.Nbd2 O-O 6.h3 {this is largely to secure the h2 square so that we can preserve our dark square bishop for instance against Nh5.}) 2.c4 e6 3.Nc3 Bb4 4.Qc2 O-O 5.a3 {white by choice, not forced, plays a3 to resolve the pressure on c3 in order to finish development more deliberately, with choices such as Bg5 becoming easier to make} Bxc3+ 6.Qxc3 b6 7.Bg5

Then there are reactive cases where tactically one may not have a choice but to challenge a piece on g4 or b4 respectively, in which case although there's no doubt your opponent would be forcing your hand into playing h3 (a3), but you will have to include that move and accept a small set-back. Extreme cases are when a mate is threatened, e.g., a queen on h5 and knight on g4.

Why moving the castled-side pawns would generally be a set-back?

Main reason for that is two-fold: First, as obvious as it may sound, you'd be permanently committing to a pawn structure, second and tightly related to the first, you'd be creating targets for your opponent. The latter may be, to name a few, in the form of weakened dark squares, for instance if there's a dark-square battery on the c7-h2 diagonal that you'd want to preferably deal with by playing g3, but having previously played h3 may make that difficult and g3 would expose h3 and g3 itself to potential sacrifices. Another type of target would be, a pawn push on the king-side by your opponent, challenging h3 with g4 attempting to undermine your king-side pawns and open a file towards your king.

The takeaway here can be generalized: pawn moves in chess are always a commitment, the later you have to commit to them, the more pawn structures you can opt for, and conversely, the sooner you commit to one, be it willingly or forced by your opponent, the earlier you create targets for your opponent. Targets are not always weak pieces/pawns (such as back pawns, or isolated ones), but they can also be strategic targets that can be exploited in your position, prime example being weakened-black/white-squares, or more abstractly, your pawn-breaks in the position can become limited, and the few remaining ones can more easily be prevented/delayed by your opponent, which ultimately means you will have a hard time undermining your opponent's structure and creating active play. This is closely related to space control in chess, which you can read more about here. With all of this in mind, now you can see for example why the English opening is generally is hard to face: it is extremely versatile in pawn structures it can lead to, consequently, the opponent has a harder time to resolve the dilemma of which plan to opt for! Instead, e4 and d4 openings are more committal by definition (as we start by moving a central pawn already), so we can more reliably establish systems against them

Now let's take an extreme example where our rule of thumb is being perfectly illustrated:

 [title "Michael Adams vs Garry Kasparov, Linares 2005"]
 [fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be3 e6 7.Be2 Qc7 8.Qd2 b5 9.a3 Bb7 10.f3 Nc6 11.O-O-O b4 12.axb4 Nxb4 13.g4 Be7 14.g5 Nd7 15.h4 Nc5 16.Kb1 Rb8 17.h5 O-O 18.g6 Bf6 19.Rdg1 Ba8 20.Bg5 Be5 21.gxh7+ Kxh7 22.Nb3 Nxc2 23.Nxc5 Na3+ 24.Ka2 Qxc5 25.Na4 Nc2 26.Kb1 Qa3 0-1

Notice how Kasparov pushes with a6-b5-b4 on the queen-side in order to launch his attack on white's long castled king and yet never moves any of his king-side pawns until the end as to avoid giving white any entry-points or targets. Notice how Adams had to play earlier a3 in order to prevent b4 as it would force his c3 knight to be mis-placed in turn weakening the e4 support. And having committed to a3 is precisely the target Kasparov used with b5-b4 to open the b-file, which he then exploited beautifully. This is a cherry picked example, but it's very appropriate here because all of our previous points culminate in one game! More generally, Sicilian players are accustomed to this type of pawn structures (i.e., knowing not to commit their king-side pawns and just push as fast as possible on the queen-side).


Is there an option in the pairing program to set this?

Of course.

Different approved Swiss pairing programs will do this is different ways. You should check out the User Manuals for the different programs to see how this is done.

For instance, in the Vega program go to the File menu, Round Manager, Avoid Pairs option and you can specify groups of players who should not be paired against each other for certain rounds. Generally speaking this should not be done in the last round where one of the players is on more than 50% even in the case of Iranian v Israeli since this can affect prizes and important placings.

  Algorithmically, is it done in such a way that these matches are
  considered played already (through some flag
  "playedAgainstEachOther=true") or in some other way?

This is a programming question rather than a chess question and does not belong here.


The issue is that 4. d5 is a much better move; White establishes a strong center with tempo and drives the c6 knight to a bad position.

Besides, 3... Nf6 isn't that popular either (probably because of 4. d5); 3... exd4 is the main line of the Scotch Game.


Problematic lines for black in accelerated dragon

If you play the accelerated through the move order 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 g6 then the most problematic would be the  maroczy bind after 5.c4.

But then through that move order you may not even get it as opponents may instead of 3.d4 play 3.Bb5 (Rossolimo) which is very popular.

If you play it through the move order 1.e4 c5 2.Nf3 g6 then by far the most testing line is 3.d4 cxd4 4.Qxd4 and both sides have to be very well prepared but black more than white for sure.


Eight pawns vs seven exercise: how to win?

I figured winning a pawn up in a pawn endgame is a useful skill to
  know

It is a useful skill to know and an even more important skill to know is when a pawn-up endgame is a win and when it is a draw and when it could be either depending on who is to move first. This is a vital skill because it stops you from swapping off into a drawn king and pawn endgame when you are a pawn up.

  I had been thinking about exercises to help players <1400 gain
  confidence.

When it comes to building confidence in pawn-up endgames for <1400 players this is where you / they should start. This is a win for white if it is white's turn and a draw if it is black's turn.

[FEN "4k3/8/8/8/8/8/4P3/4K3 w - - 0 0"]

This teaches you the importance of:

The opposition and
Getting your king in front of your passed pawn not
behind

In terms of preventing (or aiming for) drawing blockades the <1400 player needs to know this position and why it is a win for white if it is white's turn and a draw if it is black's turn.

[FEN "8/ppp3k1/8/PPP3K1/8/8/8/8 w - - 0 0"]

This teaches you that it is the position of the pieces which is key not material balance. White to play wins by sacrificing a pawn or even two depending on black's response.

Finally, Capablanca's Position:

[FEN "6k1/7p/8/8/8/8/6PP/6K1 w - - 0 0"]

It is a win for white but if black knows the ending it is very easy for white to go wrong and end up in a drawn position. Many white players much stronger than 1400 would struggle to win this against a knowledgeable black opponent.

All 3 of the positions above could arise from the position in the question. All 3 have far fewer pieces and so are much simpler but are far from straightforward. Mastering them first would be a good first step.


What is the green/red line in this analysis

It seems obvious to me that a red line indicates a bad move and a green line a good move. Graphically this shows in the fact that steep lines are red and horizontal lines are green. This might be slightly confusing because the graph shows the moves of both, black and white.

Because an engine always assumes best play when evaluating a position you can never improve your position by playing a move, best case scenario is you play the best move and the eval stays the same -> horizontal line. A mistake on the other hand changes the evaluation -> the line goes up if black moved, or down if white moved.

There is probably a cutoff for what constitutes a bad move, something like a 1.0 pawns evaluation drop seems likely.


What is the average length of a game of chess?

EDIT: I opened Mega Database 2012 and found there were 515539 games ranging from the 1400s to 2011. As I couldn't find an efficient way to parse the data, I just used the median move value (I hope it's normally distributed. It's probably not though as the largest number of moves was 277... oh well). The median value was 37 moves, but I'm sure that it's a right-skewed distribution given the max value. If I had to hazard a guess to the average value, I'd put it slightly greater than 40 :)

In addition, keep in mind that these are all recorded games. This means that their origin can be from tournaments, matches, or even online competitions. Indeed, the 277 move game was played in a tournament on the Internet Chess Club.

Oddly enough, I found that the average length of a game (played by humans) is roughly 40 moves. Based on the statistics provided by the Chessgames database (685,801) games, the average number of moves is 40.04. Chessgames tends to only include player games of a high caliber, so this doesn't really take into account amateur tournaments. As these games are played by humans, few of them tend to end in checkmate but rather a draw by mutual agreement or a resignation in a lost position.

This may not be the best source, but I've played in over 320 tournaments in my life and many of these games are imported into my personal database. The average number of moves per game is around 38.

I do not have access to my Mega Database 2012 (a database provided by Chessbase) at the moment, but I will post the average number of moves of approximately 5 million historical games when I open it.


Is it possible to win with a king and one bishop vs a king?

No. There is no position you can construct in which the black king is in check (has to be from the bishop), white only has king and bishop and the black king can't move.
The closest you can get is this:
[fen "k7/1BK5/8/8/8/8/8/8 w - - 0 1"]

And the black king can move to a7.


Is there a description of the files used by USCF ratings reports?

Google turned up many ways to read or convert DBF files as well as detailed descriptions of the contents.

See the gory details here
https://en.wikipedia.org/wiki/.dbf#File_architecture_overview

and yet more gory here:
http://www.dbase.com/Knowledgebase/INT/db7_file_fmt.htm

with more details still at this site
http://web.archive.org/web/20150323061445/http://ulisse.elettra.trieste.it/services/doc/dbase/DBFstruct.htm

yet another view of the DBF file
https://www.dbf2002.com/dbf-file-format.html


Meaning of move stats in opening databases

You have to keep in mind that a tree of variations isn't actually a tree. You can reach the same position in many different ways, i.e. the branches can grow back together. So when you go through a variations the number of games doesn't necessarily dwindle until there is just one game left, occasionally games from another move order will join the fray and possibly change the statistics a lot.

So if you are following ten games with 90% for white, but reach a position that was also reached by a different move order, suddenly you might be looking at 50 games. And if for some reason white did much worse in the additional 40 games, the statistics will flip.

This is not as unlikely as it seems, because employing a different move order can indicate different overall knowledge of an opening. For example the 40-games move order may have been all the rage in a time when a very good later continuation for white wasn't known.


Why do many players resign from chess in a relative young age? And become coaches or writers instead?

A lot of chess players make a living off of chess coaching. You can't make enough money by playing tournaments unless you're like top 100 in the world. Therefore I assume that some people must have to resort to writing books and coaching people in order to make enough money. Considering that they resign at a young age, they must plan this out. On top of that, I would assume that maybe when you combine family life (if you're a father or mother) with coaching, having a small normal job, and a tireness from travelling, then you'll never have time to play at tournaments.

By the way, I would say that no, they haven't reached their peak, that's not why. Just look at Mark Dvoretsky, he is only an IM, but he could definitely be a GM if he wanted. It is because of personal choices, financial reasons, and convenience reasons. Or, maybe they just love teaching but hate playing in serious competitions due to stress. Besides, tournaments can cost tons of money.

Chess is considered the second most stressful sport behind skydiving.


Rejected game variant for adding a new chess piece

I was unable to find a variant with a 9x9 board that included this piece, but that doesn't mean such a variant doesn't exist.

Perhaps you slightly misremembered the powers of the piece. Modern Chess was invented in 1968 by Gabriel Vicente Maura, according to Wikipedia.  It has a 9x9 board and features a piece called the "prime minister" which combines the powers of the bishop and knight.  Unlike any piece in normal chess, it is capable of delivering checkmate without the help of another piece, if the opponent's king is in the corner.

It's also possible you may be thinking of Chancellor Chess.  This was  invented by Benjamin R. Foster in 1887, according to Wikipedia.  It has a 9x9 board and features a piece called the "chancellor", which combines the powers of a rook and knight.

If you're sure that the piece was actually a queen and knight combined (and not a bishop and knight or rook and knight), then Wikipedia says this is called the "amazon", and that it has also been called "angel, ayanu, commander, crown prince, elephant, empress, general, giraffe, grand chancellor, maharajah, rettah, royal guard, superqueen, tetra queen, and wyvern".


How do I not play too fast when playing the computer?

This is a very bad habit you are getting in to. Of course it doesn't really matter if you lose to the computer in this situation but you will face something similar in OTB play with clocks.

If you have 10 minutes left to finish the game and your opponent has less than 2 minutes then this is a very big advantage for you. If you are not playing with increments then your opponent will have to start blitzing his moves out to try and avoid losing on time. He is much more likely to make a mistake. If you copy him and start blitzing too then your advantage disappears.

You should try and have a set routine which you go through regardless of the opponent's speed of move, some questions you automatically ask yourself. Why did my opponent play his last move? What is he threatening? How does it stop my plans? Does it give me some new possibilities?

If you consider these kind of questions it will slow down your play and help you to stop blitzing unnecessarily.


This game between Ponomariov and Carlsen was quite a sensation in 2010. Especially because there is no single outrageous blunder - Ponomariov is just outplayed very systematically. Alas, one has to keep in mind that it was a rapid game.

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3
Bg7 7. Bc4 c5 8. Ne2 Nc6 9. Be3 O-O 10. O-O Qc7 11. Rb1 Rd8
12. Bf4 Be5 13. Bxe5 Nxe5 14. Bb3 Ng4 15. Ng3 Qf4 16. h3 Nf6
17. e5 Nd5 18. Ne2 Qe4 19. Ng3 Qf4 20. dxc5 Be6 21. Qd4 b6
22. Ne2 Qf5 23. cxb6 Nxb6 24. Qf4 Rac8 25. Qxf5 Bxf5 26. Rbd1
Bd3 27. Rfe1 a5 28. Nf4 Bc4 29. Rxd8 Rxd8 30. Re4 Bxb3 31. axb3 Rd1
32. Kh2 Rb1 33. c4 Rxb3 34. c5 Nd7 35. c6 Nb6 36. Rd4 Rc3
37. Nd5 Nxd5 38. Rxd5 Rxc6 39. Rxa5 Rc4 40. Kg3 e6 41. f4 h6
42. Kf3 Rc3 43. Kf2 g5 44. fxg5 hxg5
45. Ra4 Kg7 46. Rg4 Kh6 47. g3 Kh5 48. Ra4 Kg6 49. Ra5 Rd3
50. h4 gxh4 51. gxh4 Rd7 52. Ke3 Rb7 53. Kf4 Rb4 54. Kg3 Kf5
55. Ra7 Rg4 56. Kf3 Rg7 57. Ra5 Rg1 58. Rb5 Ra1 59. Rc5 Ra3
60. Kf2 Ke4 61. h5 Ra8 62. Kg3 Kf5 63. Kh4 Ra4 64. Kg3 Rg4
65. Kf3 Rf4 66. Kg3 Kg5 67. h6 Rg4 68. Kf3 Rh4 69. Rc7 Kg6
70. Rc8 Rxh6 71. Kg4 Rh1 72. Rg8 Kh7 73. Ra8 Rf1 74. Ra2 Kg6
75. Rg2 Rf5 76. Re2 Kg7 77. Kg3 Kf8 78. Re4 Ke7 79. Kg4 Kd7
80. Rd4 Kc6 81. Rd6 Kc7 82. Rd1 Rxe5 83. Rf1 f5 84. Kg5 Kd6
85. Kf6 Re4 86. Rd1 Kc5 87. Rd8 f4 88. Kg5 e5 89. Kg4 Re3
90. Rd1 Kc4 91. Rd2 f3 92. Kg3 e4 93. Kf2 Rd3 94. Ra2 Kd4
95. Ra4 Ke5 96. Kg3 Rd2 97. Ra5 Kd4 98. Ra4 Ke3 99. Ra3 Ke2
100. Kf4 f2 0-1


Is there any documented game by Benjamin Blumenfeld where he played Blumenfeld Gambit?

I am sorry I have no sources, but I have read somewhere (maybe in Yermolinsky's The Road to Chess Improvement - but apparently not) that no, there isn't any known game of Blumenfeld employing his eponym opening. The gambit is named such just because Alekhine, when annotating his famous Blumenfeld win against Tarrasch, wrote that "4...b5 is an idea by Blumenfeld".


Caro-Kann Bronstein-Larsen Variation For Black

If you read Danish there's Bent Larsen's Solide åbninger (Solid openings) from 1980.

It is a repertoire book for beginners (white and black) and suggests the line you inquire about as the defense against 1. e4.


Is there a method or tip to best memorize current enemy pieces' movements?

What you are talking about is called "board vision". Googling "chess board vision" will get you a ton of stuff.

One thing that may help. On looking at an enemy piece (or one of your own) do not ask "where is it?" but ask directly "what is it doing?". For example, that Bishop is controlling that diagonal, which is annoying because I would like to use some of those squares. The battle for control of an important square might involve pieces close to or far away from that square, but they should be linked in your mind as participants in the same struggle. Psychologists call this chunking. You can remember things about a group of pieces more easily than about the individual pieces.


My item here does not "explain the controversy", but for a contemporary tournament comment concerning Morphy, see top of page 90 here: https://archive.org/details/bookoffirstameri00fisk

From the First American Chess Congress book, quoting an article in The Chess Monthly:

  Mr. Morphy is rapid in his moves and quick in his combinations, his
  time on any move never having reached a quarter of an hour; Mr.
  Paulsen is exceedingly slow, some of his moves having occupied more
  than an hour and several in succession having exceeded thirty minutes.

On page 246 and 248, specific listings of moves longer than 5 minutes for two of the Morphy-Paulsen games are given, and a similar comment on page 255.


What service can be used to save and replay/analyze a chess match?

For an online tool, lichess is good. You can enter your game and have it analysed by a computer engine.

The analysed game will have annotations in plain language ("mistake/blunder/inaccuracy") and of course contain the computer evaluation score after each move.

Once you have a game analysed on lichess, they have another good feature called: "Learn from your mistakes". Here it will ask you at every mistake/blunder to find a better move.

Another feature which might help you is called "chess insights", basically statistics of your games (e.g. which opening did you score best, etc).

You can do much the same (and more) offline using a chess database software. Scid is a popular free one, chessbase a popular non-free one. However as a beginner you might find the lichess features sufficient and more easy to use. In any case you can import/export between lichess and chess databases.

Particularly for a beginner it is difficult to properly analyze a game. Computers will tell you about tactical mistakes, but finding problems in strategy/positional play using computers will be just about impossible on your own. Therefore I would suggest to find a stronger player look over your games and give you tips. Ideally you'd join a chess club, but if that's not an option you could also post your games in online forums.

Another way to improve is to read or watch commented games, particularly those in the openings you play.


Is this considered checkmate if I touch a piece which can't make a legal move?

No. The touch-move rule can't force you to make an illegal move, and it is not legal to put yourself in check.

Here's what the FIDE laws of chess say:

  4.5 If none of the pieces touched in accordance with Article 4.3 or
  Article 4.4 can be moved or captured, the player may make any legal
  move


In the Delayed Open Catalan, what is the best move after 7. Ne5 c5 8. dxc5 Qc7 9. Nxc4 Rd8?

I play the Catalan in a constant basis, and in this position I would play Qb3 for the following reasons:

10.Qa4 => does not look that great because at any moment black can play Bd7 (gaining a tempo on the queen) and then Bc6, and thus, releasing some of the pressure in the light squares of the queenside.

Line:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. Nf3 d5 2. d4 Nf6 3. c4 e6 4. g3 Be7 5. Bg2 O-O 6. O-O dxc4 7. Ne5 c5 8. dxc5 Qc7 9. Nxc4 Rd8 10. Qa4 Bd7 11. Qb4 Bc6

10.Qc2 => leave the queen "tactically vulnerable" and, in some lines, disconnect the queen from the knight in c4 (after Nc3, for instance). Two SAMPLES lines to consider:

Example 01:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. Nf3 d5 2. d4 Nf6 3. c4 e6 4. g3 Be7 5. Bg2 O-O 6. O-O dxc4 7. Ne5 c5 8. dxc5 Qc7 9. Nxc4 Rd8 10. Qc2 Bxc5 11. Nc3 Bxf2+ 12. Rxf2 Qxc4

Example 02:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. Nf3 d5 2. d4 Nf6 3. c4 e6 4. g3 Be7 5. Bg2 O-O 6. O-O dxc4 7. Ne5 c5 8. dxc5 Qc7 9. Nxc4 Rd8 10. Qc2 Bxc5 11. h3 b5 12. Ncd2 Bxf2+ 13. Rxf2 Qxc2

I'm not saying in any way, shape or form that these lines are good, I'm just trying to point out the tactical themes that could arise from such positions.

10.Qb3 => There is no tempo gaining move on the queen. The knight on c4 would be protected even after the natural move Nc3. And you keep the pressure on b7.

The three moves are good but if you want a quiet, positional game but maintaining long term pressure I would recommend Qb3. The other 2 keep some dynamism in the position and could bring complications in the long run.


In the general case K+N vs K+P is of course a draw - or a win for the pawn if it can promote unhindered.
There is however a famous construction were the knight can force a mate against a king stuck in front of its own well-advanced rook pawn:
[fen "8/3N4/8/8/8/p7/k7/2K5 w - - 0 1"]

1.Nc5 Ka1 2.Kc2 Ka2 3.Nd3 Ka1 4.Nc1 a2 5.Nb3#

There are many variations on that theme, the first such position being published by in the Bonus Socius before 1300.


What is the best strategy for white in this position?

I think the f4-plan is doomed to fail. It would be beautiful if we could achieve it in good conditions, however, as you pointed out, f4 is met with ...exf4 followed by probably ...Qe7 and Nd7-e5. We get rid of the pressure on the 'a' file though, so it's better than doing nothing.

If we went for g3, preparing for gxf4 after f4, our effort will be met by ...f5! shattering our dreams.

It would be interesting to try to put our light-squared bishop on a4, but I don't see it working either after 1.Qd3 Nd7 2.Bb5 and now even Nb6 does fine

For those reasons, I think the best answer here is to immediately play c3!? It's true that Black has ...Ra2, but after Qe1 I don't really think it does much. If Black captured on c3, our queen would be now in a great square to fight for the a file. If Black does NOT capture, then we can begin to put some pressure on b4


What term is used to describe the following situation?

As @Ywapom notes, Zugzwang is often used to the describe the end of this situation, like the Immortal Zugzwang Game where Sämisch suffers this fate against Nimzowitsch.

For the progress itself, it's perfectly normal to use non-chess specific terminology here, e.g. you could say White was slowly getting strangled by Black in the game above.


What do we know about how to get better at chess?

There is a 2006 paper "Training in chess: A scientific approach" by Dr. Gobet from the University of Nottingham, and Dr. Jansen from Carnegie Mellon University, which goal was "...to show how recent findings in cognitive psychology can be applied to improve techniques of chess training, teaching, and learning"
It concludes that learning occurs best:

from the simple to the complex
when the elements to be learnt are clearly identified
when following an "improving spiral"  (this is similar to what DeGroot found in how a chess player thinks with progressive deepening).

Then using the above knowledge the authors used their "template theory" and used it to review various chess training techniques.
Some conclusions they get doing that are:
(in the area of Explicit Knowledge)

focus on a limited number of positions and openings and learn the various methods in these positions thoroughly.
repetition will be necessary.
avoid too much historical and anecdotal details.

(in the area of Implicit Knowledge)

Using a computer to view variations can greatly cut down on the time to do so, but may offer less efficient encoding of the information [in your brain].
Find a balance between rote learning and understanding (specifically in studying the opening).
study openings from different points of view -- for example, by linking it to the middlegame or endgame.
use a chess database for your repertoire as "memory is fallible!) and you will need to review it frequently.

They also mention the "decomposition method" which consists of studying and playing basic endgame positions -- basically removing most the pieces from the board in common middlegame structures.
In studying endgames the claim the "improving spiral" can be best applied.  I would compare this to how endgame table-bases are being created; basically solving the game backwards.
In studying tactics they suggest starting by themes and only later random.
They also defy some previous claims like "go through each variation once" and "blindfold chess is good for your chess"; going as far to say blindfold chess may actually be harmful to one's development.
They also think that studying composed puzzles is useless.
They then reiterate DeGroot's earlier findings on the importance of "pattern recognition".
As the paper was built on past studies I think it pretty much shows what scholars think of how chess learning should be approached scientifically.
Personally, I agree with their suggestion of studying in chunks and repetition.  It is easy to get overloaded when studying chess.


Bobby Fischer photos in his NY apartment?

Here are two pictures of Bobby Fischer (Robert James Fischer), in a New York apartment, mainly taken from the movie (documentary) Bobby Fischer Against The World.(I have no rights to this pictures ,but I think I can post them in some networking sites).


You need to stop playing "Hope Chess" and start playing "Real Chess."

Dan Heisman gives the definition of Hope Chess as follows:

  "HOPE" Chess - This is NOT when you make a move and hope your opponent
  doesn't see your threat. Instead, Hope chess is when you make a move
  and don't look at what your opponent might threaten on his next move,
  and whether you can meet that threat on your next move. Instead, you
  just wait until next move and see what he does, and then hope you can
  meet any threats. In my first 3 tournaments I played Hope chess and
  never won more than 1 game in any of the three. The speed at which you
  can play Hope chess also explains why I usually took only about half
  an hour for each game in these tournaments, even though the time
  control was 50 moves in 2 hours. Most high school level players play
  hope chess, but almost always lose when they run into a serious player
  who plays "Real Chess."

NM Heisman gives his simplified "Real Chess" thought process:

1) How the opponent's move changed the position and if threaten to do something positive.

2) What the goal/plan is for the position.

3) What the candidate moves are. A candidate move is a move that might do something positive, so you should at least look at it.

4) Which of the moves are safe. Omitting this step is Hope Chess.

5) Which of the safe candidates moves is best. At the end of this step, do a blunder check.

If you wait until the blunder check to make sure all responses to your move do not cause you to lose the game, this will limit your results. I used to play this way and could not get over 1300.


What plan should black have followed in this game?

Plans are not usually so long range and specific. Your opponent will be trying to do things that you cannot ignore. Plans are often a collection of piece improvement ideas that work together to control important squares and put pressure on your opponents position.

Part of your plan could be developing your light square bishop on b7. This looks to help control the central light squares, and might long term put pressure on white's kingside.

If you want to put your bishop on b7, then b7-b6 is a priority. a7-a6 does not go with this idea, as you point out.

White's bishop on c4 does not have a lot to do and does not need to be driven off with 10...Nb6. This also gets in the way of developing your bishop to b7.

On move 10, white's bishop on b2 is not very good. You should look to controlling the d5-square to prevent white d4-d5. You should support your pawn on c5. It brings pressure on white's center, and if white takes d4xc5 his pawn structure will be weakened. Qc7, Rfd8, Rac8 look like good places for the heavy pieces to help control the central squares, and the possibility of white ending up with weak pawns on the c or d files. Qc7 and Nd7 help control e5, and might provide a chance for an e6-e5 break.

A knight posted on e4 goes well with a bishop on b7.

This plan on move 10 would need to be continually adjusted based on what white does.


Is an arbiter allowed to leave the playing hall while some games haven't finished yet?

The first thing to note is that for low level tournaments there is not even a requirement for a qualified arbiter to be on site. The arbiter must be a licensed arbiter (International Arbiter, FIDE Arbiter or National Arbiter) but is not required to actually be there. They can be at home watching TV. If there is a problem they can be consulted on the phone.
For reference here is what the FIDE Rating Regulations effective from 1 July 2017 have to say about arbiters for FIDE rated events:

0.3 All arbiters of a FIDE rated tournament shall be licensed otherwise the tournament shall not be rated.
0.4 Tournament reports for all official FIDE and Continental events must be submitted and shall be rated. The Chief Arbiter is responsible for the results submitted.
9.1 The Chief Arbiter of a FIDE registered tournament has to provide the tournament report (TRF file) within 7 days after the end of the tournament to the Rating Officer of the federation where the tournament took place. The Rating Officer shall be responsible for uploading the TRF file to the FIDE Rating Server not later than 30 days after the end of the tournament.

No mention of the arbiter actually having to be there and some federations run FIDE rated leagues where there are two or three licensed arbiters for the league but dozens of clubs where the matches are played with no arbiter present.
For Norm events (tournaments where there are enough highly rated and titled players from enough different federations for it to be possible to get a title norm) the rules are a lot stricter.
This is what International Title Regulations (Qualification Commission) / FIDE Title Regulations effective from 1 July 2017 has to say:

1.16 The Chief Arbiter of a title tournament shall be an International Arbiter (IA) or FIDE Arbiter (FA). He may appoint a temporary deputy. An IA or FA must always be in the playing venue.

Let's just remind ourselves of how the FIDE Laws of Chess define "playing venue" and "playing area".

11.2.1 The ‘playing venue’ is defined as the ‘playing area’, rest rooms, toilets, refreshment area, area set aside for smoking and other places as designated by the arbiter.
11.2.2 The playing area is defined as the place where the games of a competition are played.

So, even in a high level norm tournament the arbiter is allowed to leave the playing area and go to the toilet, go and have a smoke, go and get a coffee.


You shouldn't give a fig about "variations". Players don't lose games in the opening because they're bad at this variation or that system, they lose short games because they're bad at tactics (and that's your experience, yeah?).
Forget the dumb names of things. Pawn Storm This, Big Attack That. You have to learn enough tactics first.


How can white mate black in 4 moves in this particular game.

The king has no escape squares and, as is often the case in these puzzles, every move must be a check.

[FEN "r1br4/1p3qp1/p1kb3p/2NN1p2/1PPQ4/8/P5PP/R4RK1 w - - 0 1"]

1. b5+ axb5 2. cxb5+ Kxb5 3. Rfb1+ Kc6 4. Rb6#


What are the most common checks in chess?

What are the most common checks which occur in chess?

Back rank checks (and check mates) must be the number one. I would suspect that bishop checks from h2/h7 on the castled king should also be up there in the top 10 if not number two.


Need some helps with the tactics in the middle game

Chess is a skill that requires hard work and dedicated toning, just like learning to play a musical instrument. Unless you are very exceptional, you won't become a master at it within a few weeks, months or years (the good news is that you don't have to be a master to have fun with chess). Some players were lucky enough to be very talented, had the opportunity to start young and maintained an almost obsessive interest in it - they are the ones most likely to become IM's or GM's after 10 to 15 year of dedication. Most of us just play for fun and must maintain a realistic perspective.

I suggest you read Willy Hendriks' book "Move First, Think Later". The book addresses the very essence of your question, which is: How do I improve my chess?

As a warning, the book is controversial, especially since it spends a lot of effort in undermining certain common conceptions about chess improvement. Hendriks is not scared of taking on the establishment of chess training.

From memory, here is a list of things he suggests you focus on:

Tactical puzzles. Nothing improves your chess quicker than doing a lot (as in thousands) of puzzles, as it "programs" your brain to spot good moves and continuations.
Play a lot. Over the board, on the internet, as much as you have an appetite for.
Notate and study your games. Try to understand where you went wrong (I, for example, found I have a weakness in spotting tactics on my king behind the pawn line).
Focus on the things that motivate you. For example, here on chess.SE you will often see the advice "don't study opening theory at beginner level". Well, if you like studying opening theory, then studying opening theory is perfectly fine.

Here is a list of things he suggests you don't waste your time on:

Worrying about general rules and common adages (for example "the bishop pair", "respond to an attack on the flank with an attack in the center", leave your thinking time for the "critical moment")
Approaching chess from some ideological/academic angle (like Silman's "imbalances"). Hendriks argues that chess ability is not a rational skill, and a rational-based approach will not help in improving it greatly (this point probably needs some elaboration - he's not saying chess is irrational, but that taking some kind of reasoned approach won't help you much - you are going to be better off with an intuition toned through practice than over-the-board reasoning).
Worrying about developing some kind of structured thought process (for example: 1. Consider threats. 2. Consider attack points. 3. Consider tactical motifs. 4. Consider alternatives etc etc). Hendriks argues from findings in neuroscience that your brain functions heavily in parallel - don't try to serialize your thinking by adopting a thought process that sub-divides goals - instead, let your brain do its work naturally. Just find the good move!
Trying to calculate every position 10 moves deep. GM's don't generally calculate that deep (unless the tactical situation calls for it, of course).
Following some abstract "plan". Rather, focus on finding good squares for you pieces and making good moves that forces your opponent to counter actively.
Spending 10,000 hours doing it even if you hate it.


How to play against Nimzo-Larsen attack if White starts with 1.Nf3

What about 1.Nf3 Nf6 2.b3 d5 3.Bb2 Bg4?
Black development plan is very simple, the main line goes like this:
[FEN ""]
1. Nf3 Nf6 2. b3 d5 3. Bb2 Bg4 4. e3 Nbd7
5. Be2 e6 6. O-O Bd6 7. c4 c6 8. d4 O-O 9. Nbd2

In this position, despite white bishop aiming it is own pawn it is still potentially dangerous; therefore, standard e5 or c5 breaks are not usual in this position.
The safest approach for black is try to exchange the dark-squared bishops with 9...Qe7 10. Ne5 Ba3.
Another approach, most intuitive in my opinion, is 9...Ne4 10. Nxe4 dxe4 If white plays 11. Nd2 then after 11. Bxe2 Qxe2. 12...f5 black has play on the king side, the bishop is aiming at h2 and the queen can be brought to h4 or/and rook to h6 via f6. If white plays 11. Ne5 and then 11... Bxe2 12.Qxe2 black could play 12...f6 forcing 13. Nxd7 and here again black can play on the king's side.
It is also common to bring the queen play 9...Qc7 or 9...Qb8 with the aim of controlling the e5 square and preventing Ne5. But I am not very familiar with this plan.
Also, the position you describe can be reached via 1.Nf3 Nf6 2.g3 move order.
[FEN ""]
1. Nf3 Nf6 2. g3 d5 3. Bg2 e6 4. O-O Be7
5. b3 O-O 6. Bb2 c5 7. c4

to avoid it you can go for the same black setup, with the bishop on g4.


How do opening books in engine chess work?

Your understanding is more or less correct, an opening book is a large collection of positions and what are the "book moves" in that position. I don't know if engines typically choose at random if there are multiple moves in the book for a given position or if they do something more complicated, but that doesn't matter much for your question.

  How can an opening book "beat" another?

It can contain better moves, and more of them, and they could even be better tailored to the specific opponent!

To figure out which is better, you let the same engine play against itself, with one side using one opening book and the other side the other. If you take care to have each book play white as often as black, you can see in the end which book had a higher score against the other book.

For instance, an opening book could contain a line somewhere that actually is not as good as the author thought at the time of putting it together, and the other book chooses to go for that position as the other side and it leads to a win for the engine.

Or one book is "done" after 15 moves after which the engine is on its own, but the other book still has several moves coming up after it on which the engine spent far more time on while creating the book than it could during the actual game.

Or the author of the opening book for engine A knows that engine B is worse at playing certain positions from the French, and he chooses to put moves into the book that causes A to go for those positions whenever it has the chance.

Or an opening book author spends days analyzing a certain position in an opening, and finally figures out that there is a way to force a good position for white there, and he adds it to the opening book. Engines with books that still allow that position to come up will have a bad time there.

And so on, opening books are in the end created by humans (with heavy use of engines) and the same arms race is going on there as between top human players.


Is there a chess GUI that gives an evaluation of each move?

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

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

tl;dr

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


2...d5 risky but playable,

3.Ne2 not that good either Nf3 o exd5

3...g5? positionally bad, better dxe4 and later QxQ taking away castle to white or better develop a piece

4.Nc3 provocative but later N is uncomfortable in b5 and ends badly in a3

6...Bxa3 fine now white has some holes too in the pawn structure

7...b5? again positionally unsound it appears black does not know how to develop pieces

8.Rb1 what for? better Ng3 and later Be2 to complete development and control the white squares that are weak for black

10.f4?? till 12.Bxf4 why? this is not correct, simply loses material white is close to lost: as above you had to develop with Ng3, Be2 and 0-0

13...Qe4 a useless check that forgets the B in a2 under attack and returns the material advantage

till 21.e5 relatively normal play (no huge blunders) but 21...Rg6?? loses material in 3 moves sequence (white takes Q R and N vs Q and B) 21...Nd5 was better: after 24...Kxd8 white is totally winning

26.Bb8 till 28.Bxd4 this again was a useless material sacrifice why go in b8 in the firs place? You had to rearrange pieces bringing the rook from a2 to e1 and start attacking: white is still winning but it is harder

30... h5?? is a huge blunder and black is again totally lost now: the rook is trapped and can be captured with Kg2, a move you never played

32.Rg2?? white had to play Kg2 attacking the Rh3 now black could free it with 32...h4, but this remains valid for just a move

from now on white wins by taking all the black pawns which was fine still the rook hanging in h3 was to be taken with Kg2 attacking it-

as suggested you should learn the basics of material counting


Can you solve this unique chess problem of white's two queens vs black's six rooks?

It's checkmate in 20 moves. White's queens circle around the board giving checks, and Black interposes horizontally/vertically moving pieces. Black only has one choice because the other piece is pinned from the previous check. That goes well, until the pawn needs to move sideways:
[FEN "3Q4/7Q/3rp3/2rkr3/2rrr3/7K/8/8 w - - 0 1"]

1. Qb7+ Rc6 2. Qa5+ Rc5 3. Qb3+ Rc4 4. Qd2+ Rd4 5. Qf3+ Re4 6. Qg5+ e5 7. Qf7+ Re6 8. Qd8+ Rd6
9. Qb7+ Rc6 10. Qa5+ Rc5 11. Qb3+ Rc4 12. Qd2+ Rd4 13. Qf3+ e4 14. Qg5+ Re5 15. Qf7+ Re6 16. Qd8+ Rd6
17. Qb7+ Rc6 18. Qa5+ Rc5 19. Qb3+ Rc4 20. Qd2# 1-0


Did it make sense for Lasker to play the Exchange variation of the Ruy Lopez in 1914?

It made perfect sense.

He was very familiar with the opening:

  Lasker played hundreds of practice games with the Exchange Variation of the Ruy Lopez and discovered what he thought was every mistake White or Black could make.

Source: #247: 300 Wisest Things Said about Chess: With 300 Annotated Positions

Lasker was well known to adapt his playing style to the opponent's psychology.

  Lasker was considered to have a "psychological" method of play in which he considered the subjective qualities of his opponent, in addition to the objective requirements of his position on the board. Richard Réti published a lengthy analysis of Lasker's play in which he concluded that Lasker deliberately played inferior moves that he knew would make his opponent uncomfortable.

Source: wikipedia

Your research has shown that the opening took Capablanca out of his stride and scored the full point, so yes it made perfect sense.


Tools to analyse weaknesses based on Lichess history

Yes. Certainly. AimChess does exactly that. You may want to pay for it.


Is the Evans Gambit declined good for black?

Evans gambit is not popular anymore.

The problem with the Evans gambit comes when Black accepts the gambit since he can return the gambit pawn in proper moment to defuse White's attack.

This is the crucial line:

[fen ""]

 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 d6 7.Qb3 Qd7 8.dxe5 Bb6!=

Until this day nobody was able to find edge for White-that is why nobody plays it anymore.

  I looked at it and I don't see anything wrong with it. I can't go over all the variations here, but you could look for an article or a Youtube video

Forget the YouTube and find opinions of the strongest Grandmasters.

Quality of those videos is usually low, as they intend to get subscribers by showing them attractive variations instead objectively the best lines.

Not a single theoretical main line was examined properly-only sidelines that give Black poor play.

  I can only see black losing, so what's wrong with Evans Gambit declined?

Declining the gambit is not the best option for Black. White has no problems since he gets the initiative because his opening idea was fulfilled. He will use his free tempo to further hinder coordination of the Black pieces.

Still, Black has good play in all lines, but must defend first for a long time, and attack later.

  Am I missing a variation?

If all your sources provide as "quality" coverage as the video you linked to-then yes, you do miss a lot.

I will quote the Chess Informant ECO 2006 for the lines in Evans gambit declined:

LEGEND OF SYMBOLS:

+/=    Minimal advantage for White

=/+    Minimal advantage for Black

+/-    White is better

-/+    Black is better

=/∞    Compensation for material

∞      Unclear

+-     White wins

-+     Black wins

->     Attack

↑      Initiative

[fen ""]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bb6 (4...d5 5.exd5 Nb4 6.O-O Nf6 7.Nxe5 Nbxd5 8.d4 Bd6 9.Bg5 c6 10.Nd2 O-O 11.Qf3 h6 12.Bh4 Be6 13.Rab1+/=) 5.a4 ( 5.Bb2 d6 6.a4 a6 7.b5 axb5 8.axb5 Rxa1 9.Bxa1 Nd4 10.Nxd4 exd4 11.c3 Nf6 12.O-O O-O 13.d3 d5= ) ( 5.b5 Na5 6.Nxe5 Nh6 ( 6...Bd4 7.Nxf7 Qf6 8.Qe2 Nxc4 9.Nxh8 Ne5 10.Nc3 Ne7 11.Bb2+/= ) 7.d4 d6 8.Bxh6 dxe5! 9.Bxg7 Rg8 10.Bxf7+ Kxf7 11.Bxe5 Qg5 12.Nd2 ( 12.Nc3? Nc4-/+ ) 12...Be6 13.Qf3 Ke7 14.O-O-O! Raf8 15.Qa3+ Kd8 16.f4 Qe7!? 17.Qxe7+ Kxe7 18.g3 Bxa2∞ ) 5...a6 ( 5...a5 6.b5 Nd4 7.Nxd4 ( 7.Nxe5 Qg5 8.O-O ( 8.Bxf7+ Kf8 9.Ng4=/∞ ) 8...Qxe5 9.c3 Ne6 10.Re1 Nf6 ( 10...Bxf2 11.Kxf2 Qc5+ 12.d4 Qxc4 13.Re3 Nf8 14.d5 Qc5 15.Ba3 Qb6 16.d6=/∞↑)  11.d4 Nxd4 12.cxd4 Qxd4 (12...Bxd4 13.Ra2=/∞ ) 13.Qe2!? (13.Qxd4!? Bxd4 14.Ra2=/∞ ) 13...Qxa1 14.e5=/∞↑ ) 7...Bxd4 8.c3 Bb6 9.d4 Qe7 (9...exd4 10.O-O! Ne7 11.Bg5 h6 12.Bxe7 Qxe7 13.cxd4 Qb4 14.Na3 O-O 15.Qd3 d5! 16.exd5 Bd7 17.Nc2 Qd6 18.Ne3+/= ) 10.O-O ( 10.Qg4 Nf6 11.Qxg7 Rg8 12.Qh6 Rg6∞ ) 10...d6 11.f4 ( 11.Be3!? ) 11...Be6 12.Na3 exd4 13.cxd4 O-O-O 14.Be2 Nf6 15.Bf3 d5 16.e5 Ne4 17.Nc2 h5!= ) 6.Nc3 Nf6 7.Nd5 ( 7.d4 Bxd4!? ( 7...exd4 8.Nd5 Nxd5 9.exd5 Qe7 10.Kf1! Ne5 11.d6 cxd6 12.Bd5=/∞ ) 8.Nxd4 Nxd4 9.f4 ( 9.O-O d6 10.f4 Be6! 11.Bxe6 fxe6 12.Be3 Nc6 13.b5 axb5 14.axb5 Rxa1 15.Qxa1 Ng4!? 16.bxc6 Nxe3 17.Qa2 Nxf1 18.Qxe6 Qe7 19.Qc8+ Qd8 20.cxb7 O-O 21.Nd5! Kf7 22.Qf5+ Kg8 23.Qc8= ) 9...d6 10.O-O O-O 11.fxe5 dxe5 12.Nd5 Be6 13.Nxf6+ gxf6 14.Bd3 Qe7 ( 14...Nb3? 15.cxb3 Qd4+ 16.Kh1 Qxa1 17.Qf3!+-->) 15.Bh6 Rfd8∞) 7...Nxd5 ( 7...Nxe4 8.O-O d6 9.d3 Nf6 10.Bg5+/= ) 8.exd5 Nd4 ( 8...e4?+/- ) 9.a5 Ba7 10.d6 ( 10.O-O?!=/+ ) 10...cxd6 11.O-O O-O 12.Nxd4 Bxd4 13.c3 Ba7 14.Qf3=/∞

  How could black win against Evans Gambit declined?

How could he not win?

In all the variations above Black has sufficient counter-play and equal chances to win.

He will first try to parry White's initiative, and then he will have won endgame due to his healthier pawn structure and White being overextended-this is a standard plan for Black in most openings.

Summary:

Evans gambit is not popular anymore because White does not get the attack he hoped for, and after Black properly returns the pawn he has better or at least equal chances in the endgame. Why would anyone play with White just to fight an uphill battle to draw?

As for the declined variation, White will get lasting initiative but Black still holds. In all lines quoted above Black has sufficient counter-play and both players need to play accurate in order not to lose.

For a detailed coverage of the Evans gambit find repertoire books like The Great Evans Gambit Debate series or Play the Evans gambit-Tim Harding.

Hopefully this answer sheds some light. If you have further questions leave a comment and I will try to respond as soon as possible.

Best regards.


Difference between chess puzzle and chess problem in this episode of The Queen's Gambit?

As a chess composer, seeing most problems being called puzzles is rather frustrating. A while ago, I personally revamped the problem and puzzles tags.
The problem tag says:

Chess problems consist of a board position and a task. Most ask for a
line of play that mates black in a set amount of moves, or a
combination that results in a winning position. Many other types
exist, including, but not limited to, construction tasks for various
positions and proof games that have numerous goals, selfmates,
helpmates, and retrograde analysis. Tournaments and championships
exist for composing of original problems and for speed-solving.

The puzzle tag says:

Often, a puzzle type of problem in which a tactical or positional
solution is required, like White/Black to move and win”, in what is
often a middlegame of endgame-esqe position. But a puzzle can also be
a chess riddle, chess math. or any other non-normal chess problem.
Questions about solving puzzle, puzzle apps and websites, how to
understand the idea behind a puzzle, etc. are also on-topic.

To my knowledge, these are generally accepted definitions by the chess composing community. I expect @Laska to have more input here.


You're correct. The idea of 24...a6 is to allow the king to avoid a perpetual. This could be of relevance if Black's queen moves away to go after White's king (e.g., ...Qc5). It could also be useful for the king to hide on a7 if things go haywire and a dangerous attack happens, such as the h-pawn promoting or White's rook getting involved. Although, in the position before 24...a6, Stockfish gives an evaluation of 0.00 no matter whose move it is. So purely in an objective sense, ...a6 isn't a necessary move -- but practically it's quite nice. Your anticipated move of 24...Qh4 is also evaluated at 0.00 by Stockfish, so it's just as good.
One interesting line goes 24...a6 25.h6 (White has other moves that are fine too) 25...Qc5. Now White's going to get mated from ...Qf2 if he's not careful. For example, 26.Qe8 Qf2 27.Qe7+ Kb8 28.Qf8+ Ka7. Now White can't stop the dual threats of ...Qxb2# and ...Qc2+ (picking up the d1-rook with mate). Another faulty try is 26.Qg7. The idea is that 26...Rxg7 27.hxg7 sees White about to promote, leaving him up a rook. However, Black has 26...Qf2, and 27.Qxf7+ Kb6 28.Qxe6+ Ka7 sees Black's king being safe, again thanks to the a6-pawn. Therefore, White's only 26th move which maintains equality is 26.Ka1!, preparing to defend with Rb1 if needed.


Is there a common list of steps to analyse/annotate one's game?

As Andrew points out in a comment, the subject of your post overlaps substantially with an earlier one, whose answers address the general mechanics of analyzing one's own games, and would probably be of use to you. I'd like to address just one small part of your question that doesn't overlap:

  In the search for critical positions - do you start from the beginning, or from the end (last move)?

Now whether a position in a game is "critical" or not isn't some objective feature of the position itself, but is rather a function of the position and the player who faces it. What I mean is: many a position in which you or I would say that we have a critical decision to make, Capablanca or Fischer might recognize it as trivial, and in other positions where we might blindly think there's nothing important to consider, players like them might say instead that there are deep considerations to be made.

So I don't think you need to be going through your game after the fact (forward, backward or any other way) trying to identify what the critical junctures were. You know what positions you considered critical when you were playing the game (when you agonized over choosing between two moves, when you spent a looooong time thinking, etc.), and those are critical points where self-analysis can be especially beneficial.

One habit you could get into is making a note of such moments on your scoresheet while you're playing (circle the move, make an X, whatever). Then not too long after the game, try to record as much of what your thought process was at those points. Later on you can look at what you were thinking during the game in a fresh light, and try to find improvements to your in-game mental analysis. Speaking to another part of your question: checking yourself with an engine is a good idea, but you should try to catch your own mistakes first, and only then let Stockfish or whatever show you all kinds of things you never considered or noticed.


If you feel that if you could change seats with your opponent and play his side and win then your decision was correct. He was good enough to get such a big advantage. If you could win from his position then, likely, so can he.

If, on the other hand, you don't know how you would win if you could swap positions, then don't resign. It could be that he doesn't know how to win either. Instead try and work out how to make his task as difficult as possible. It may be that you can get a draw.


Is KQB vs KP generally sufficient to force a selfmate?

That one is a no-brainer: with a knight pawn the white king can stand in the corner, and be blocked in with just the bishop. This is impossible with another pawn - you must block both e.g. b1 and d1 and need a third White piece. (After all, Black must be forced to play d2#, so Qb1/Bd1 won't suffice!)
EDIT: Considering other material, if I recall correctly, KQR vs KQ is sufficient for forcing selfmate. (Again, check PDB.) A request at MatPlus Forum came up with this gem (Black can promote into all four pieces, always leading to a selfmate in 7 more moves):
Look for 1st prize
I.e. you, not surprisingly, can force a self mate with Black only having an e-pawn and White a bit more of material.


How is it like for live audience watching long classic chess?

I helped out at the 2008 match between Kramnik and Anand in Bonn and attended many other world class events as a spectator. (Like Kramnik-Fritz when he blundered the mate in one. Epic.)

Usually seats aren't reserved and people come and go. Often there is a separate commentary/analysis room that you might attend, although you can also hear commentary with headphones in the playing hall. If you are accompanied by friends you might occasionally slip out to discuss the current position.

But many people are actually sitting though almost the entire game, with only the occasional toilet break etc. Time flies when you are having fun. And of course 7h games aren't the norm.


Well, if the player can force stalemate, then he isn't lost. So the strict answer is no :-)

There are many elementary endgames where a successful defence is possible only because of stalemate, like king + pawn vs pawn:

[FEN "8/3k4/8/2KP4/8/8/8/8 b KQkq - 0 1"]

1...Kc7! 2.d6+ Kd7 3.Kd5 Kd8 4.Kc6 Kc8 5.d7+ Kd8 Kd6 =

or king + queen vs king + pawn with the pawn on the c file:

[FEN "7K/8/6Q1/8/8/8/2p5/1k6 w KQkq - 0 1"]

1.Kg7 Kb2 2.Qb6+ Ka1 3.Qc5 Kb1 4.Qb4+ Ka1 5.Qc3 Kb1 6.Qb3+ Ka1!

and if white takes the pawn now, it's stalemate, so he can't progress.


Allie's search is a combination of MCTS and Minimax. The MCTS is very much like you would find in AlphaZero or LC0 as it was taken from the same papers. In addition to MCTS, Allie also does a minimax based backup of the tree whenever a new MCTS batch is evaluated by the NN. This minimax backup is then used to modify the Q values of the nodes in the tree that were either 'min' or 'max'. This modification is a further averaging of the MCTS based backups.

So:

Allie uses MCTS for playouts and for back prop in much the same way as A0 and Lc0
Allie also does a minimax-based back prop to supplement that mcts based back prop

I've also tried many, many, many, different ways of adding newer AB/Minimax to the algorithm, but so far nothing that has successfully gained elo over the above. Finally, I'll note that in all of my testing of Allie (pure MCTS) vs Allie (MCTS+Minimax) the latter has scored significantly higher so I am confident that it does improve elo at least in self play.

UPDATE:

Since I wrote this, the Allie minimax backup has grown more complicated. Now, in positions where the best candidate move is a terminal node Allie does a pure minimax based backup with no mcts averaging. If the best is proven best among all of its siblings, then the parent is also made terminal and assigned the inverse score of the best child. If the best is not proven, then it still does pure minimax backup, but the parent continues to be expanded and if a sibling becomes best it switches back to the combination of minimax+mcts backup. Finally, this is all kept track of for transpositions too.


Position from the Dutch Defence / Blackmar-Diemer gambit

You raise a very interesting point - you're absolutely correct in saying that 3...f5 is not a common response to the Blackmar-Diemer gambit. However, the gambit can be reached in another way where Black doesn't have the option of playing this move:

[FEN ""]
1. d4 d5 2. Nc3 Nf6 3. e4 dxe4 4. f3

In the Dutch, Black can sidestep White by playing this move:

[FEN ""]
1. d4 f5 2. Nc3 Nf6

Your question as to why it isn't played more in the Dutch/more against the Blackmar-Diemer is a bit difficult to answer. Aside from the examples above where White or Black can sidestep this line, it can be reached in the main line of the Dutch against 2...d5 and the mainline of the Blackmar-Diemer with 2. e4. It should be better for either White or Black, so why don't we see it more often?

In my opinion, I think that White has sufficient compensation for the pawn due to the weak e5 square and the possibilities of playing f3, undermining Black's pawn structure. If we go with this assumption, then we're looking at the first scenario in the Dutch Defense. I believe that there are more common replies to 1...f5 such as 2. g3 and 2. Nf3 which tend to score better than the gambit line outlined in the question.

On the flip side, I noticed that Black actually scores better with this line in practice, so I'm rather quite torn. I believe you've hit upon something rather original, and I encourage you to do a bit of studying into the lines yourself and arrive at your own conclusion :) maybe you have found a new main line!


I'm wondering, what is the equivalent method of practicing tactics methodically in chess? Would it be to practice one motif repeatedly? Or is it to practice blitz+standard?

Neither.
In the chess world it seems to be to use some variation of "spaced repetition". There is a great answer by BlindKungFuMaster to a different question which says:

Spaced repetition is a learning technique that repeats content after increasing time spans according to learning success, i.e. faster for stuff you haven't grasped yet, longer if you do well.
In chess this is either used to learn a certain set of (easy) tactical exercises basically by heart ("woodpecker method" according to Axel Smith, Michael de la Maza, …), which is supposed to improve your tactical pattern recognition.

Since BlindKungFuMaster's excellent post Axel Smith and Hans Tikkanen have published a book expanding on the "woodpecker method" called "The Woodpecker Method" which includes some interesting history and background together with instructions and explanations of the method plus over 1100 graded exercise.
The main difference between spaced repetition and the woodpecker method is that Smith and Tikkanen emphasize increasing speed rather than time gap. Here are their instructions:

Step 1
Cycle 1: Solve as many exercises as you can manage in four weeks. These exercises are your set; and solving them brings you to the end of your first cycle. (The exact time period can be adjusted according to your lifestyle and circumstances, but try not to spend much more than four weeks. If you find yourself taking much longer than four weeks, you have probably either not been putting in sufficient time, or have included too many exercises in your set.)

Step 2
Take a break from chess for at least a clear day, and up to a week if you need it.
Step 3
Cycle 2: Solve the same set of exercises but faster: within two weeks is the target.
Step 4
Repeat steps 2 and 3, and repeat again. Aim to complete each cycle in half the number of days as the previous cycle (rounded up, when dealing with an odd number of days).
Step 5
The Woodpecker Method has been completed when the full set of exercises has been solved
entirely in one day – or after the 7th cycle, if you are unable to solve the full set in a day. In the final two cycles, you should focus more on spotting ideas, patterns and motifs at speed, and less on the finer details of calculation.

Interesting to note that Axel Smith credits the woodpecker method (named after the translation of Tikkanen's name into English) with his achievement of the GM title. This is what he says early in the book:

As mentioned above, I trained with the Woodpecker Method in the spring of 2010. That summer, I achieved three GM norms and surpassed the 2500 barrier, all within a seven-week period. The positive eﬀects did not stop there: the following year, my live rating brieﬂy peaked at 2601.
Such quick results from any type of chess training are rare in my experience, but for me the Woodpecker Method seemed to be just what the doctor ordered! The increased tactical acuity and consistency that came from working so hard with the method significantly decreased my blunders and made me more confident at the board.
Would I have made the same improvement with some other type of training? It’s not impossible – but my playing strength had not taken any significant leap in years, so I had been at a loss as to what to do diﬀerently to succeed. Although the Woodpecker Method probably wasn’t the only way for me to raise my play, it certainly proved to be a way. The intersection of my interest in the human mind and my motivation to stop blundering surely helped me to devote more time and eﬀort than I would have put into my usual training.


Is castling possible with a pawn promoted to a rook?

No, according to FIDE's Laws of Chess, castling has to be done along the first rank.
§3.8.2:

3.8.2 by ‘castling’. This is a move of the king and either rook of the same
colour along the player’s first rank, counting as a single move of the
king and executed as follows: the king is transferred from its
original square two squares towards the rook on its original square,
then that rook is transferred to the square the king has just crossed.
3.8.2.1   The right to castle has been lost:
3.8.2.1.1 if the king has already moved, or
3.8.2.1.2 with a rook that has already moved.
3.8.2.2   Castling is prevented temporarily:
3.8.2.2.1 if the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one
or more of the opponent's pieces, or
3.8.2.2.2 if there is any piece between the king and the rook with which castling is to be effected.


Chessbase 14 - How do I enumerate variations in it?

Options > Notation > Structured Variations


Why can't I place the rook in front of the queen?

The Rook on c4 is pinned against the your King by the black Queen. Thus you can't move it without exposing your King to the Queen's wrath.


Having run stockfish for a couple of days, I can confirm there is at least a mate in 15.


How is a perpetual check reached in this puzzle?

I think that Kf2 is actually the winning move for White and the perpetual results after gxf3.
[FEN "4Q/4p1bk/1p1qp2p/p1p1n2B/4P/2P3B1/PP4P/6K b - - 0 1"]

1. Nf3 gxf3 2. Qxg3+

Now the White king can not escape the perpetual even though the Black king is very close to checkmate.


A chess problem (need help with analysis)

If white does not take the knight on c5 after 1. Rac1, Nc5, the c4 pawn will be lost after 2.Q-somewhere, Nxd3 3.Qxd3, Bxc4. And that is just horrible for white.


I think the main idea od .. d5 here is to undermine the outpost.  Hence the followup should not be a quick .. d4, but rather trying to keep pressure on e4.  I don't like .. d4 for more than one reason: it makes Bc5 bad, and it tempts White to Bc2-b3 returning to the best diagonal.  My plan would be:

.. d5 motivated as above
.. Bf8 to shore up the kingside and to avoid a hit with tempo on Bc5
.. b4 starting to open lines on queenside and taking aim at White's center from the side
if White does nothing, .. a4 and then .. a3 will break up her pawn chain, eventually gaining the d4 square for Black.  White can counter this by plaing a3 herself but that creates more scope for Black counterplay on the queenside like maybe Nf6-d7-c5-b3.

Now, of course White also moves, and the best use of that will be to cook something up on the kingside.  The side who gets there first will rule the game, and that's how it should be.  Human compatible, 20th century chess :-)


Can a player be forced to adjust a piece?

When FIDE tournament rules apply: If you displace one or more pieces – knocking off the board, intentionally or unintentionally, is a displacement – you have to re-establish the correct position on your own time (Art. 7.4.1). While it is not specifically mentioned, I would say that you have to do this at once; if you wait, that could be regarded as an attempt to "distract or annoy the opponent" (Art. 11.5).

In a regular game, if you proceed while the incorrect position is on the board, any move will be regarded as irregular, the correct position before the knocking off will be reinstated, the game will continue from that position, the arbiter will set the clock and give penalties. In rapid and blitz games, after the opponent made a move, the game will continue without the "vanished" piece.

USCF might have additional rules.


I think this is doable. However, it will depend on the number of pieces in the required position.
You see that many openings can be reached in multiple ways
(X,Y,Z,...) -> P; where X, Y and Z are the sets of moves that get you from the initial position to the required position P.

This problem is NP-hard, because you can never know for sure which road was selected!

The best way for you is to study the positions of known games (which is most of the time is the case). Then search for [1] the game and play it back from the beginning.


The answer depends on whether or not the games are being recorded. The way this is elliptically referenced in the FIDE Laws of Chess is that a distinction is made between, on the one hand, standard time controls (where moves must be recorded by the players), rapid and blitz games played at a sufficiently high level that there are enough arbiters to record the games and on the other hand regular rapid and blitz where nobody is recording the rules.
In the first case article 7.5.1 applies and the games is restarted from the last known legal position and various penalties can apply.

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

According to Appendix A 7.5.1 also applies for rapid where:

A.3.1.1 one arbiter supervises at most three games and
A.3.1.2 each game is recorded by the arbiter or his assistant and, if possible, by electronic means.

And for blitz according to Appendix B where

B.3.1.1 one arbiter supervises one game and
B.3.1.2 each game is recorded by the arbiter or his assistant and, if possible, by electronic means

Otherwise for rapid and blitz (recording not done / not possible) illegal moves are not punished and not corrected unless either the arbiter or one of the players spots what has happened before another move has been made:

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

There is an additional twist for rapid and blitz to handle the position where the arbiter comes late to the scene and spots your last scenario:

my opponent moves a piece on the other side of the board leaving the kings checking each other and hits the clock, what happens here?

The arbiter waits one move to see if the illegal position is corrected and if not declares a draw.

A.4.4 If the arbiter observes both kings are in check, or a pawn on the rank furthest from its starting position, he shall wait until the next move is completed. Then, if an illegal position is still on the board, he shall declare the game drawn

If the arbiter doesn't see it then the game between Larry and Mo continues.


Which interface protocol should I implement for my chess engine?

There're only two protocols - UCI and Winboard. Winboard is an old protocol and not really being used nowadays. Crafty is the only major engine still supporting the Winboard protocol, but it's only because the engine is also very old. UCI is a newer protocol developed by Shredder, and is used everywhere - Windows, Macs, Linux, Android, iOS etc. UCI is really the only protocol you should consider.

UCI is supported everywhere
Every chess GUI other than xboard supports UCI, such as, Chessbase, Scid, Arena etc. Even xboard can connect to a UCI engine by something known as Polyglot.
UCI documentation is at http://wbec-ridderkerk.nl/html/UCIProtocol.html

Winboard has more or less obsoleted because the protocol is more complicated than the cleaner UCI. Winboard is a stated protocol, it means the engine state depends on the previous iterations, whereas UCI is easier to deal with as you only have to supply with your current FEN or a move-list.


Is there Python code to use the Leela neural network?

Python utilities for experimenting with Leela Chess Zero a neural network based chess engine: https://github.com/glinscott/leela-chess/

Here: https://github.com/so-much-meta/lczero_tools
This allows you to run the network in Python on specific board positions via python-chess, and get policy/value outputs. (Works with pytorch, and is also able to run the network using the tfprocess training module included in Leela).

https://github.com/dkappe/leela-chess-weights/wiki/Supervised-Learning
A newer, faster tool for converting pgn to training data can be found here.


Why is Byrne vs. Fischer (1956) regarded as the "Game of the Century"?

The "Game of the Century" was a term coined by Hans Kmoch in Chess Review. In short it was a bit of sensationalism. While Fischer did show a talent for combinations and an impressive sacrifice, the real importance of the game was the story of a leading chess master vs a phenomenal prodigy about to begin his historic rise.

Still, it's helpful to note what David Levy said: "In my opinion, however, the game, attractive though it is, can in no way be held in such high exaltation. It was merely the fact that the combination was created by a thirteen-old boy that brought the game so much publicity. Had it been played in the Barnet League between two sixty-year-old men it is doubtful whether it would have been considered worthy of publication".

As for the game between Tal and Smyslov, the similarities in age are easy to spot, but the chess playing doesn't really compare.

The full game and commentary can be found over at Wikipedia.


Is it important to have pawns at the centre of the board?

I'm going to assume that the importance of the center in general terms is already something you are aware of. In short, controlling the center means that your pieces will be able to access/utilize the whole board much better than if your opponent does.

Pawns allow a strong control of the center by virtue of the fact that they are both weak (meaning your opponent will be unlikely to trade a stronger piece for one) and the fact that they cannot move backwards or readily across files (meaning that it's relatively easy to create situations where one side's pawns cannot be attacked by the opponent's pawns, even if material is even). This of course assumes that one player is occupying the center with pawns (see: 'big center') and the other is not.

A more likely situation is one where both players are occupying the center with pawns, and the more important effect of this is that it helps determine the character of the game. If the center is blocked, the position is often vastly different to when the center pawns are traded for each other, leaving plenty of room for the long-range pieces to move around. Neither of these situations is inherently better for one side, but can allow a player to reach positions they are more comfortable with, or use their pieces more effectively than the opponents (e.g. a wide-open position can generally be said to favor a side that has bishops instead of knights, if there in an inequality there).


Is there any better play than the 3-move mate?

There is a two-move mate: the Fool's Mate. However, it requires White to be, as the name implies, extremely foolish!

[FEN ""]
1.g4 e5 2.f3 Qh4#

As you can see, this mate relies on White advancing pawns without any regard for his King's safety. There's no way to force a two move checkmate (if there were, Chess would be an awfully boring game!).

As to whether it's ever occurred in real (master) play, I can't find any record of it, though the Wikipedia article mentions Teed vs. Delmar, 1896, where a very similar mate is delivered a few moves later.


Are there any moves in the opening stage that are perfectly sound but not book moves?

Obviously, you are not the first chess player to think about alternatives to the 'book moves'.

I think it is a solid assumption that all possible moves that deviate from the book move have been considered by someone already, and probably by someone with some playing strength.
So either those moves are good enough (equivalent) to 'book moves' and therefore they would have made it in the books by now, or they are (considered) at least slightly inferior.

If you consider playing an inferior move, you will have to balance the expected 'loss' from the inferiority against the potential 'gain' from forcing your opponent into a non-book variant (which you have analyzed in depth before, and he probably didn't). Depending on his strength in 'book openings' compared to his strength in 'think-yourself', this might be a good deal for you or not.

Note that this is not an uncommon idea - nearly all chess players I know have taken this approach from time to time, and more or less successful. Try it, but don't expect your opponent to be shocked out of his mind.