If your question is under standard time controls, then player A wins, because it is not the sole responsibility of player A to claim the win; in fact it is the duty of the arbiter to immediately declare the win (so in some sense, it would be unfair not to award player A a win simply because the arbiter was not around when player B's flag fell first), which is the main reason why the clock will indicate which flag fell first.

(If I recall correctly, when Carlsen lost on time against Topalov recently at the Norway 2015 event, it was the arbiter that pointed out the flag fall, without any claim by Topalov.)

On the other hand, in a rapidplay or quicker setting, you need to have at least one second on your own clock to claim a win on time, otherwise either player may claim a draw if both flags have fallen; the arbiter (and certainly any outside observer) will refrain from pointing out a loss on time for either player--even if both flags fall and one player gets mated (or resigns), the win result will stand if neither player notices the other's loss on time.


After f6 White takes with the bishop and Black loses a piece (bishop on c5 since d6 square is attacked by the white knight and f8 is attacked by the white pawn; no other piece is protecting the bishop).


Just guessing without reading all of the code to understand completely.

1) The third condition to not preform a Null Move is zugswang.  Another hint is that INF is used to report a mate-in-x.

2)  The purpose of a Null Move is to determine if we could do nothing and still be better so to cause an early cutoff.  I assume that they represent a pawn value as 100, so they want a slightly higher favorable eval before it causes a cutoff.


Is any tool which allow analyse EPD file and add evaluation score per I want specify depth/multi PVL?

With  GradualTest, you can use it to control an engine to analyze a set of positions. The only version available through web.archive is 2.4 (a compiled version and program source) but exists version 2.6. The author is Gunnar Malin, available in GitHub.

Its syntax is:
GradualTest [switches]

** switches:

/a -    Init time in second, default=2.
/c -    Command to reset hash. Defaults to 'new'.
/e -    Method to set up the board. Values: edit, cbedit or setboard.
        Default=setboard. (cbedit is used if the engine have implemented
        Chessbase's method of edit.)
/i -    Input file to be tested.
/o -    Output file.
/s -    Init string for the engine. Defaults to
  'xboard\nhard\neasy\nnew\nlevel 1 1440 0\npost\n'.
/t -    Time to use at each position.
/w -    File to write positions with move not found.
/g -    File to write positions with only good moves
/u -    Use the UCI protocol.

It write also the following epd fields:

acd - Depth of the search for the pv line.
acn - Number of node serched for the pv line.
acs - Seconds searched for the pv line.
ce  - Centipawn evaluation of the pv line.
pm  - The best move from the engine.
pv  - The last pv line (pv=Predicted Variation).

With crafty (a winboard engine) I configured it in 'crafty.rc', sd=21 for instance, but with enough time to reach a depth of 21 ply. When the time to reach this depth was inferior than the time provided with GradualTest, the program somehow knows that position analyze has finished and proceded with the following position.


How do you calculate your Tournament Performance Rating?

TPR calculators and expected rating change.

http://englishchess.org.uk/Juniors/tournament-performance-calculator/
http://www.uschess.org/content/view/13146/836/

Basically Performance rating is the average of your opponent's ratings with an adjustment based on the score of the game.  For each win, you add your opponent's rating + 400, a draw is just your opponent's rating, and a loss is your opponent's rating - 400.  There is an exception for a perfect score, then the adjustment is 800.


Can a chess book (or ebook) have too many diagrams?

Let's start by saying that that's a subjective question. What is "too many" for one person may be just right for another.

That being said, let's take a ridiculous case: A diagram for every move, whether main line or variation. The diagrams would get in the way of the exposition. It's safe to say that very few chess players would benefit from such a book.

The "most friendly" chess books I have read include diagrams every 6-10 moves of the main line only, whether with or without exposition. There is a reason behind this. Buffering and Human Memory describes this phenomenon, with a full paper called The Magical Number 7. Briefly, humans can remember 7+/-2 discrete items without having to switch knowledge in and out of "storage".

This will also arrange matters such that a reader can follow the play without a board, but make it desirable nonetheless that a board be used. In addition, if the reader makes an error in replaying moves, 6-10 move intervals make reasonable "checkpoints" to return to.


Each individual site will have their own rules, although many of them will be the same.

I haven't played online in years, so I can't list specifics, but I know the rating systems are different from site to site.


How do delay and increment work, exactly?

Nothing gets rounded internally. If you are programming a chess clock, then maintain the time according to whatever the machine precision is on your machine without rounding. Some clocks have tenth seconds on their display, but that doesn't mean that they're altering the fundamental increments of time as compared to different clocks.

If A begins and spends 2.5 seconds on his first move, then he will have exactly 14:59.5 left. Just because it displays 15:00 doesn't mean that he still has 15:00. If he spent 2.6 seconds, then he has exactly 14:59.4 left, which may display as 14:59.

Likewise with increment. He will have exactly 14:57.5 + 2 = 14:59.5 seconds on his clock, which may display as 15:00.


Why do some players play bizarre openings?

The reason that top players generally avoid nonstandard openings is that they usually allow a sufficiently skilled opponent to equalize (with black) or gain an advantage (with white).

To do this against an opening which you haven't seen before, though, takes time. In a blitz game, the opponent will not be able to figure out the best way to exploit an inaccuracy. A player like Nakamura (who probably played every single legal first move on ICC at some point) has enough middlegame and endgame skill that a slight opening disadvantage really doesn't mean anything.

Also, it's online blitz. They aren't playing for prizes, they aren't jeopardizing tournament invitations. They can basically do whatever they want and if they lose, nobody really cares.

Edit now that you added the game:

Both players are clearly just messing around. Just because you CAN play chess well doesn't mean that you always want to. Don't try to draw conclusions based on this game.


What are examples of grandmaster games where both Black and White castle opposite sides and the queenside players loses?

That's a pretty typical scenario, you'll find a lot of examples if you search for games in the sicilian opening.

[Event "Sarajevo"]
[Site "Sarajevo BIH"]
[Date "2000.05.29"]
[EventDate "2000.05.17"]
[Round "11"]
[Result "0-1"]
[White "Sergei Movsesian"]
[Black "Garry Kasparov"]
[ECO "B90"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "64"]
[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.f3
b5 8.Qd2 Nbd7 9.O-O-O Bb7 10.g4 Nb6 11.Qf2 Nfd7 12.Kb1 Rc8
13.Bd3 Rxc3 14.bxc3 Qc7 15.Ne2 Be7 16.g5 O-O 17.h4 Na4 18.Bc1
Ne5 19.h5 d5 20.Qh2 Bd6 21.Qh3 Nxd3 22.cxd3 b4 23.cxb4 Rc8
24.Ka1 dxe4 25.fxe4 Bxe4 26.g6 Bxh1 27.Qxh1 Bxb4 28.gxf7+ Kf8
29.Qg2 Rb8 30.Bb2 Nxb2 31.Nd4 Nxd1 32.Nxe6+ Kxf7 0-1


It does take awhile for FIDE to update their ratings, which is monthly (see article) compared to the unofficial Live ratings site at Live Ratings. But it is interesting to note that Carlsen is due for a 2 point bump according to the Live rating site.


Good format for library of chess positions w/tags?

You could use a MySQL database with a column for the fen string and a column for the category. MySQL pairs well with php, perl, and python depending on what you w
ant to use the database for (such as a website or something you can just use personally through a browser), a WAMP server can make this easier to set up.


Ideas for giving chess lessons at school for differing levels of playing strength?

You could record your lessons for class consumption. This would be useful for students who miss lessons. Please make sure if it's legal to record group lessons in your school though.


Fairy endgame statistics for KDDDDvKN (D=dabbaba; '2,0' leaper)?

I was unable to generate data for exactly what you want, but I managed something with a restriction to 6x6 board. I think it's reasonable to assume that it doesn't make a big difference from 8x8 for this specific case since there are no powerful pieces on the board (with unrestricted movement distance).

Available positions are enumerated by starting from a certain position and doing moves until we can. It should give all possible positions but I'm not sure. (I respect the requirement posed by OP that all Ds have different available positions)

Code (C++17, uses a few MSVC specific intrinsics) (tuned for this specific piece types and configuration): https://pastebin.com/d6J5WHuY

Stripped WDL data:

        W               D               L
KvK     0.000000000%    100.000000000%  0.000000000%
KDvK    0.000000000%    0.000000000%    0.000000000%
KDDvK   0.620803000%    99.379200000%   0.000000000%
KDDDvK  25.666000000%   74.334000000%   0.000000000%
KDDDDvK 69.638300000%   30.361700000%   0.000000000%
KvKN    0.000000000%    100.000000000%  0.000000000%
KDvKN   0.000761905%    99.997700000%   0.001523810%
KDDvKN  0.083948400%    99.916000000%   0.000000000%
KDDDvKN 3.553240000%    96.446800000%   0.000000000%

        Longest DTM for white
            Longest DTM for black
KvK     0   0
KDvK    0   0
KDDvK   17  0
KDDDvK  57  0
KDDDDvK 63  0
KvKN    0   0
KDvKN   1   1
KDDvKN  17  0
KDDDvKN 63  0

I'm unable to generate KDDDDvKN as it would require ~32GiB of RAM (should take less than an hour though), which I don't have.

Buf overall it can be seen that around a quarter of KDDDvK games are winning for white which may suggest that there are non-trivial winning KDDDDvKN positions.

I also have more detailed logs with the longest winning line shown.
https://drive.google.com/drive/folders/1_aLMYB87zVJ9qslQxafTZNKHgXsoBnl2?usp=sharing

I have not added any persistence/querying and I don't plan to. Code is provided above.


White to play and checkmate in two moves

Use the fact that the rook is pinned, and that the king has few squares left;
I'm thinking that 1.Rd8 Kd3 (only possible move) 2.Nc5# should be the solution.

[White "NN"]
[Black "NN"]
[FEN "7R/1B1N4/8/3r4/1K2k3/8/5Q2/8 w - - 0 1"]

1.Rd8 Kd3 2.Nc5#


A tool to search for certain moves played

Chess Query Language operates on PGN files of games and does what you want as well as much more powerful stuff. It is a free download. There are lots of examples to get you started here.


Your proposal is a plausible way to get to that position. I wouldn't call the Scandinavian "bad" just because it moves a piece twice. It's perfectly playable.

When the trap was played in the following game, it was the knight rather than the queen which moved twice.

[Site "Sao Paulo (Brazil)"]
[Date "1973.??.??"]
[White "Nobrega Adaucto Da "]
[Black "Barata Hemar"]
[Result "1-0"]
[FEN ""]

1. e4 d5 2. exd5 Nf6 3. Nc3 Nxd5 4. Bc4 Nf6 5. Nf3 Bg4 6. Bxf7+ Kxf7 7. Ne5+ Kg8
8. Nxg4

And by the way, you have to be a little careful when playing this. Someone once tried this on me, but the position was slightly different:

[FEN ""]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 c6 5.Nf3 Nf6 6.Bc4 Bg4 D 7.Bxf7+?

And now after Kxf7 8.Ne5+, Black has Qxe5+ 9.dxe5 Bxd1 and will end up with an extra minor piece.


Computer assistance in online blitz chess

It's definitely possible.

In this video: https://www.youtube.com/watch?v=Zi47GBArpPE the user has set up a program that screen captures the board, determines the best move and then plays out that move. It's fast enough that he can play bullet (1 minute each) with it.


Regarding the AlphaZero vs Stockfish match, this question has already been covered here by SmallChess.

AlphaZero aside (which employs a specialised Monte Carlo1 routine in its exploration of the lines of play), which is made to be non-deterministic by construction, for the usual heuristics based chess engines, such as Stockfish and others (though there are other engines that have MC-based routines, AFAIK Rybka used to have such feature), the source of randomness is generally just a consequence of technical aspects in the implementation, rather than intentional randomness being introduced algorithmically in the engine's decision making. Abstractly speaking, one reason for that is the fact that the engines aren't running in a purely sequential manner (executing one task after the other). Instead, to render the engines more efficient, they perform parallel searches in various branches of the tree of possible moves. They do so via what is called multi-threading (or -processing but that is a bit different). So multiple threads of the CPUs are concurrently executing operations to search the tree (and cache the evaluations of visited positions), so imagine each thread being assigned a subtree. The problem with this kind of implementation is that the overall execution of the threads becomes highly dependent on all sorts of conditions (waiting times, RAM swaps, ...), so in the end a principal variation may be chosen without having allowed all other threads to finish their search.

This indeed happens often because the engine is set to make a decision under a certain amount of time, so time management alters the behaviour. You can also revert this statement by saying: knowing the algorithm and implementing deterministic threading routines are not sufficient to reliably predict the state of the program after any time t. Of course if one always allows all threads to finish their search, and there haven't been concurrency issues during that execution (for instance a thread trying to access a certain cache that isn't accessible), then the behaviour will indeed be fully reproducible given everything else is the same2.

1: Together with the fact that through additional training (for instance self-play) its neural network keeps evolving (re-adjusted parameters), or if you will its evaluation function doesn't have a constant, fixed definition (unlike heuristics based engines).

2: Even then, as you said, at the opening level, with an opening book, there are sometimes intentional random decisions made by the engine as to which variation to choose. Similarly, outside of the opening phase, there can be moments where multiple variations have close to equal evaluations (within the resolution chosen for the Eval), then based on the design, it may end up choosing one randomly. Finally, at the level of engine settings you have to be careful as well, for instance the depth of search and ponder times chosen for each engine (and whether they can further calculate during each other's ponder times).


You can use the SVG rendering functionalities of python-chess. This will allow you to create a SVG-formatted visualisation of any board position loaded using python-chess.
FEN to SVG
For example, given a FEN as input (say we save our python script as boardtosvg.py)
Using python3 and the python-chess library version 0.30.1
import chess
import chess.svg
import sys

arguments = sys.argv
fen = str(arguments[1])

board = chess.Board(fen)
boardsvg = chess.svg.board(board=board)
f = open("BoardVisualisedFromFEN.SVG", "w")
f.write(boardsvg)
f.close()

Example, FEN: 'rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1'

Command to run your script from the terminal:
python boardtosvg.py 'rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1'

Saved file (in case you cannot open SVGs, you can at least use a browser such as chrome to view the file):

Position from a PGN to SVG
Similarly, if the input is a PGN file, then here's how you'd for istance save the SVG of the last position of the game (you can extend this to saving the position at any move):
import chess
import chess.svg
import chess.pgn
import sys

arguments = sys.argv
pgnfilename = str(arguments[1])

#Read pgn file:
with open(pgnfilename) as f:
    game = chess.pgn.read_game(f)
#Go to the end of the game and create a chess.Board() from it:
game = game.end()
board = game.board()
boardsvg = chess.svg.board(board=board)
f = open("BoardVisualisedFromPGN.SVG", "w")
f.write(boardsvg)
f.close()

Example, PGN of Adams vs Kasparov 2005: adams_kasparov_2005.pgn
python boardtosvg.py 'adams_kasparov_2005.pgn'

Saved file:

Now all that is left to do is to convert the so-created SVG files to PNG, which you can also do in python, see the solutions in the link below:

Convert SVG to PNG in Python


What is Black's best move in this position?

[FEN "r1b1kb2/pp1p2pp/2n1qn2/3P4/3p4/2N4P/PPP2PP1/R1BQR1K1 b KQkq - 1 1"]

1... Qxe1+ 2.Qxe1+ Ne7 (2... Kd8 3.dxc6 dxc3) 3.d6 dxc3 4.dxe7 Bxe7

Yes, Black's "best" move is Qxe1+. His queen is pinned against his king, so it will be lost on the next move whatever happens. Black may as well get as much material back for the queen as possible, which means taking the rook.  But then Black is down queen for two minor pieces, with his king stuck in the centre and bad development: he should just resign.

The real question is not "What should I do if I get into this position?" but "How should I avoid getting into this position in the first place?"


How many moves needed for a knight to go from any square to any other square?

You are asking for the diameter of the knight's graph. I suppose you only want it for the ordinary 8x8 chessboard. (See OEIS sequence A232007 for diameters of knight's graphs on square boards of size nxn, in particular confirming my answer 6 for the case n = 8. The answer is alleged to be ceiling(2n/3) for n > 4.)
The answer is 6. It takes 6 moves to get from a corner square to the opposite corner, say from a8 to h1.
There are many ways to get from a8 to h1 in 6 moves, e.g. a8-c7-e8-g7-h5-g3-h1.
To see that you can't get from a8 to h1 in less than 6 moves: First note that the Euclidean distance between a8 and h1 (measured from center to center and taking the side of a square as the unit of distance) is sqrt(7^2 + 7^2) = sqrt(98). The length of a single knight move is sqrt(2^2 + 1^2) = sqrt(5), so the maximum distance you can travel in 4 knight moves is 4 * sqrt(5) = sqrt(80) < sqrt(98), so a knight can't get from a8 to h1 in 4 moves or less. But it must take an even number of moves (since a8 and h1 have the same color), so at least 6 moves are needed.
Finally I have to show that you can get from any square to any other in at most 6 moves. This will take a bit of case work.
I. Starting from e4, you can reach any square in at most 3 moves, except the squares a8, c2, c6, g2, g6.
To see this, take an 8x8 grid and write 0 on the square e4. Next, write 1 on each square that can be reached by a knight's move from e4. Next, write 2 on each unmarked square within a knight's move of a square marked 1. Finally, write 3 on each remaining square which is a knight's move from a square marked 2. You will see that every square has been marked except for the five squares a8, c2, c6, g2, g6.
II. Therefore, a knight can get from any square to any other via e4 in at most 6 moves, unless at least one of the two squares is a8, c2, c6, g2, or g6.
III. By the same procedure as in step I, you can show that from c6 you can reach any square in at most 4 moves.
IV. From c2 (or g6) you can reach any square in at most 5 moves.
V. From g2 you can reach any square in at most 5 moves.
VI. From a8 you can reach any square in at most 6 moves.
Therefore, a knight can get from any square of the 8x8 chessboard to any other in a maximum of 6 moves (5 moves if the squares have opposite colors).
P.S. @Laska pointed out in a comment that this argument can be simplified:

I think the sufficiency argument can be simplified as the e4 statement also works for e5, d4 & d5. The tricky squares for e4 are those which are 2xsqrt(2) or 4xsqrt(2) away. No square is this distance from more than one of e4, e5, d4 & d5. So given any two squares there are at least two routes in 6 or less moves. They visit different squares in the centre 4: e4, e5, d4, d5. – Laska


Looking for the complete game score of Vlastimil Jansa-Istvan Bilek, Rubinstein Memorial 1968

Here is the full game, as constructed from the OP's question and the video by IM Danny Kopec.

[FEN ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 Nc6 8. Qd2 O-O 9. Bc4 Bd7 10. O-O-O Qa5 11. Bb3 Rfc8 12. g4 Ne5 13. Kb1 b5 14. h4 b4 15. Nd5 Nxd5 16. exd5 Nc4 17. Bxc4 Rxc4 18. Nb3 Qb5 19. h5 Rac8 20. Na1 e6 21. hxg6 hxg6 22. Qh2 exd5 23. Qh7+ Kf8 24. Bh6 Bxh6 25. Qxh6+ Ke8 26. Qh8+ Ke7 27. Qh4+ f6 28. Rhe1+ Kd8 29. Qxf6+

Thesee three things not clear from the video:

1) What were the moves before 20. Na1?
2) Did the game continue on or not?
3) What was the outcome of the game?

Regarding 1)-The moves seem very reasonable to me since a large part of it is theory.

Regarding 2)-Perhaps. The position after 29. Qxf6+ is basically lost for black, but is not without hope. The white knight is currently out of play and there are still attacking chances for black, e.g. with a pawn storm.

Regarding 3)-It is likely that white won-see above.


On the Lichess database site for puzzles I found a link, where someone implemented an interface to solve puzzles "blindfolded" (i.e. without seeing the board):
https://www.tryit.in/blindfoldpuzzles/
However, because of my nonexistent knowledge in that matter, I have no idea if it's usable by blind people. It also seems limited to puzzles with very few pieces.


Check the list of Immortal games listed here :http://www.chessgames.com/perl/chesscollection?cid=1000589

Especially enjoyed Paul Morphy vs Duke Karl : http://www.chessgames.com/perl/chessgame?gid=1233404

and Lev Polugaevsky vs Rashid Gibiatovich Nezhmetdinov (this is simply stunning): http://www.chessgames.com/perl/chessgame?gid=1111459


How to exploit an opponent must-win situation

One thing is that you may adjust your opening choice, knowing that any forced draws are wins for you. For instance as white against the Najdorf, 6.Bg5 has many lines that contain forced draws, and black may be used to playing lines where he would welcome them. Now he has to avoid them and that may force him to play inferior lines.

That said -- if this makes you play openings you generally don't play, you will probably just find yourself in a sharp position that you don't know well, which is the last thing you want. And in the given tournament situation, the opponent may already be looking for openings he doesn't have any games in a database with, to avoid any special opening preparation altogether.


How often do grandmasters miss checkmate?

Probably more often than people realize.
There have been several notable instances where GMs (even world champions) have missed simple mates in one.
From my own experience, when I analyze my games the engine frequently will point out some ridiculous 25 move forced mate. In a game, I'm not going to take the time to calculate something like that out if I have a very clear, simple and direct win. Maybe it takes a couple of moves longer but who cares?


Can an Optimal Stopping strategy be applied to search functions?

No. What if recapturing your queen for an exchange is your first
candidate move?


Is it necessary to write your calculations?

No.  You could do it if it helps you.
I would not waste the time writing it down when I could be using it to learn something else.


Encyclopaedia of chess openings in machine readable form

SCID has a text file that you can use. It begins like this:

# scid.eco
#
# Encyclopaedia of Chess Openings file for Scid vs. PC
#
# Copyright (C) 1999- Shane Hudson and others.
# Last updated: Febuary, 2014
#
# In addition to standard ECO definitions, scid.eco allows for extensions:
# Each basic code can have a lower case letter extension (a-z), and an extra
# level (1-4). So the order of ECO codes for A00 is:
# A00, A00a, A00a1, A00a2, A00a3, A00a4, A00b, A00b1, ..., A00z4.
#
# You can convert this file to PGN format with the "eco2pgn.py" script,
# and to EPD with the "eco2epd" (use "make eco2pgn").

A00a "Start"  *
A00b "Barnes Opening"  1.f3 *
A00b "Fried fox"  1.f3 e5 2.Kf2 *
A00c "Kadas Opening"  1.h4 *
A00d "Clemenz Opening"  1.h3 *
A00e "Ware Opening"  1.a4 *


What happened to Alexander Alekhine's family?

According to the Italian Wikipedia his father, Aleksandr Ivanovič Alechin, died in 1917, (so probably because of the revolution) and his mother, Anes'ja Ivanovna Alechina, died in 1915 in a clinic for mental illness. Alehkine's life during the revolution is not well known. Kotov's Alekhine biography should be a valuable source.


Most important aspects of computer for scanning through databases in Chessbase?

There are really 4 components to your computer's speed and the speed that a program will achieve. These are:

1) Disk speed. For big database searches this is probably the most important. The faster the disk the better so you probably want to store your data on an SSD if possible.

2) The amount of memory. If large amounts of data are involved and the program is well written to take advantage of as much memory as you have then this is very important. For large commercial databases run by big businesses the default solution to poor performance is to add more memory but here I am talking about relational databases like Oracle, DB2, SQL Server etc. Still important for a chess database program if it is well written.

3) Number of cores or processors in the CPU. If the program is written to support multi-threading (and if it is any good then it should) then the more cores the faster it will run.

4) Raw CPU speed. This is probably the least important but still important particularly for poorly written single-threaded programs.


Is there any benefit at all to a rooks' pawn opening?

Apart from the fact that you can develop your rooks (which isn't good so early in the opening, because your rooks might become vulnerable), the only other "benefit" I can think of is that a4 (more likely than h4) can be useful after some transposition to a normal opening, e.g. stopping black from playing b5.

That being said, black can comfortably choose (thanks to your gift of a tempo) an opening where a4 is useless.

The other move 1. h4 is even more problematic because castling kingside is much more frequent than castling queenside and h4 weakens the pawn shield in front of your king.

So I don't think it's worth calling these possibilities benefits at all.


What's the difference between a USCF 1600 and 1700

This is difficult to answer. They are generally stronger in some or all of the following areas:

Tactics
Endgames
Planning
Recognition of positional features
Openings

However, they may be weaker in some of those areas than a 1600. My point is that there is no well-defined set of knowledge that makes someone a 1700-level player. They have just enough of a hodge-podge of experience and maybe some studying that they can stumble into wins against those with less experience. In fact, when you get to 1700 from 1600, you probably won't feel a tangible difference in the way you think about the game or make moves. Your results will simply be just a little better.

As for how to win against them: play better chess than they do. Study the things that I mentioned above (although I would avoid openings). One piece of advice that I've heard before for generating upsets is to make the game as complicated as possible, to maximize the likelihood that your opponent misses something major.


Did black misplay here or did I miss something?

As you saw in your game a6 failed terribly as it's simply inviting white to take on c6 and win the rook. Black had a better way of avoiding all of this a move earlier, i.e. 2. Bb5 Nf6 instead of Nge7. See illustration:

r1b1kbnr/p1pp4/1p6/4nP1p/6pq/2N5/PPP1BPPP/R1BQ1RK1 w - - 0 1

1. Qd5 Nc6
2. Bb5 Nf6
3. Re1+ Kd8
4. Qd2 (4. Qd3 Bc5) (4. Qc4 Bc5)

Finally as for Qf6, as has been suggested in comments by others, it simply loses to Ne4 (or the engine move which is Bf4, but it doesn't matter as Ne4 is good enough):

r1b1kbnr/p1pp4/1p6/4nP1p/6pq/2N5/PPP1BPPP/R1BQ1RK1 w - - 0 1

1. Qd5 Nc6
2. Bb5 Nge7
3. Re1 Qf6
4. Ne4 Qf7
5. Bxc6 dxc6
6. Qe5 Bg7
7. f6

So both a6 and Qf6 blunder the game away, the former bit more horribly so.


Maxwell,

Congrats on your request for finding correspondence games.  These are pure gems as today you can expect these games to be examples of almost perfect chess (yes, all correspondence players let the computer do 99% of the work).  You can also get databases of computer games at longer time controls to get the same 'perfect games'.

The go to database for correspondence is probably the disk that ChessBase sells and they just updated it.  http://shop.chessbase.com/en/products/corr_2015?Ref=RF70-5OH0EFN840

A while ago, Tim Harding put out a disk as well, and it may not have current games, but you never know until you check.  UltraCorr CD-ROM (Chess Mail Ltd., 2006). Followed by Ultracorr2 (2008), UltraCorr3 (2009), and UltraCorr3a (2010). No longer available.   I am not sure about the no longer available part, but google Tim Harding and ask him!

You can also download games from the ICCF (the granddaddy of all "correspondence chess") which as you may know runs the REAL World Championship. ( www dot iccf dot com) and have a look around.

Sorry I am only able to post 2 links per answer at this time.

Lastly there are probably tens of thousands of places to download games if you google it.  Here is a really good one!  http://chessgameslinks.lars-balzer.info/#correspondence-chess_worldwide    Now if you drop off the part after .info i.e. chessgameslinks dot lars-balzer dot info/  you will have enough to keep you busy even in the afterlife!


Reasons why castling may be the only winning move

Castling is an incredibly useful in chess: three moves in one. So we don't have to hunt far for reasons why it can be the best move strategically.
One common comparison is between the castling and the rook move to the d file or f file. Basically the king may need to move offensively, or defensively:

to cover a flight square for bK,
to attack a pieces (castling can be double attack),
to avoid being checked/mated,
to get out of the way so that the rook delivers check or can move.

In basic retrograde analysis, castling is used as OP pointed out, to deny the opponent's castling in certain situations.
In more sophisticated retrograde analysis, under the A Posteriori condition one player captures e.p., which would not normally be allowed, but a later castling "proves" that the e.p. was in fact justified as no other move could have been made.
In Dead Reckoning, castling may be the only way to keep the game alive, even if the result of the problem is in the end a draw. This also may allow the legality of castling to be deduced through retrograde analysis, without using the conventions. It is not normally possible to reason positively about castling using R.A.
In an antique version of the conventions, it was thought that castling would reset the counter for draw by 50 moves. So a few problems by Plaksin exploit this trick. This is still a matter of controversy even today.
There are also joke problems involving "playing at odds" so one player is missing a rook, but is still allowed to castle with the king moving twice, even though no rook actually moves. I don't know whether occupation of the vacant corner square would be enough to demolish the castling right, generally not, as some of these problems have a rook on the haunted corner square which did not originate there, either coming from the other side or promoting.
I'm aware this is a all bit dry so far, but we could find examples of all of these ideas if folk are interested.


Flexibility over solidity? Defending against 1. e4

It sounds like you are drawn to the pirc so try it out and see.  The pirc/modern is very flexible and if you play the king's indian that you can transpose into that if White plays c4 to make a universal system.

I like the fluidity of being able to see how my opponent sets up first and then respond.  I like the dynamic potential.  Rather than backward black's position feels like a "coiled spring" ready to lash out.  I haven't been blown off the board with e2-e4-e5 and h2-h4-h5 in a while so I think I am getting the hang of the direct assault lines.


Three recommendations from me:

Mastering chess strategy by GM Hellsten has annotated games with more than 350 positional exercises with detailed answers. He has also authored Mastering opening strategy and Mastering endgame strategy
Chess strategy: move by move by IM Hunt isn't quite a puzzle book, but looks at annotated games and asks you questions as you analyse the games
Practical Chess Exercises by Ray Cheng has a mix of all types of positions (tactical and positional across all phases of the game). There are a total of 600 positions with detailed explanations here


Is there a text editor with syntax highlighting for PGN files?

There is an extension for Vim (a great editor) that provides syntax highlighting for PGN. You can download Vim here. You can find the extension here.


This does sound like the famous game between Edward Lasker (not the world champ) and George Alan Thomas.

[FEN ""]
[Event "Casual game"]
[Site "London ENG"]
[Date "1912.10.29"]
[Result "1-0"]
[White "Edward Lasker"]
[Black "George Alan Thomas"]

1. d4 e6 2. Nf3 f5 3. Nc3 Nf6 4. Bg5 Be7 5. Bxf6 Bxf6 6. e4
fxe4 7. Nxe4 b6 8. Ne5 O-O 9. Bd3 Bb7 10. Qh5 Qe7 11. Qxh7+
Kxh7 12. Nxf6+ Kh6 13. Neg4+ Kg5 14. h4+ Kf4 15. g3+ Kf3
16. Be2+ Kg2 17. Rh2+ Kg1 18. Kd2# 1-0


Is there a way to automatically download KnightVision games from a chess blog?

you can do it in next way: open browser console (I tested it under google Chrome) and past next line:

document.getElementsByName("flashvars")

Then press Enter and you'll see something like this:

[<param name="flashvars" value="orientation=H&tabmode=false&light=f4f4fF&dark=0072b9&bordertext=494949&headerforeground=ffffff&mtforeground=000000&mtvariations=FF0000&mtmainline=000000&mtbackground=ffffff&pgndata=[Event "Club championship 2014"] [Site "Wellington Chess Club"] [Date "2014.12.11"] [Round "?"] [White "Michael Sole"] [Black "Aran Mol"] [Result "0-1"]  1. e4 Nc6 2. Nf3 d5 3. exd5 Qxd5 4. Nc3 Qa5 5. d4 Bg4 6. Bb5 O-O-O 7. Bxc6 bxc6 8. O-O Qh5 9. h3 Bxf3 10. Qxf3 Qxf3 11. gxf3 Nf6 12. Be3 a6 13. Ne4 e6 14. c4 h6 15. Rac1 Nd7 16. c5 f5 17. Nc3 g5 18. Rfe1 Bg7 19. Rcd1 e5 20. Ne2 f4 21. Bc1 exd4 22. Nxd4 Bxd4 23. Rxd4 Nxc5 24. Rc4 Nd3 25. Re6 Rhe8 26. Rexc6 Re1%2B 27. Kg2 Rd7 28. Rc2 Nb4 29. Bd2 Nxc2 30. Bxe1 Nxe1%2B 31. Kf1 Kb7 32. Rxh6 Nxf3 33. Rh5 Nd2%2B 34. Ke2 Ne4 35. Kf3 Re7 36. h4 Nd2%2B 37. Kg4 gxh4 38. Rxh4 f3 39. Kg3 c5 40. Rh6 Re1 41. Kf4 Re2 42. Rd6 Rxf2 43. Kf5 Re2 44. Rd3 f2 0-1">, <param name="flashvars" value="orientation=H&tabmode=false&light=f4f4fF&dark=0072b9&bordertext=494949&headerforeground=ffffff&mtforeground=000000&mtvariations=FF0000&mtmainline=000000&mtbackground=ffffff&pgndata=[Event "?"] [Site "?"] [Date "2014.12.12"] [Round "?"] [White "Croad, Nic"] [Black "Nijman, Brian"] [Result "0-1"]  1. d4 e6 2. Nf3 b6 3. g3 Bb7 4. Bg2 c5 5. O-O Nf6 6. c4 cxd4 7. Qxd4 Bc5 8. Qf4 h6 9. Nc3 Nc6 10. b3 Ne7 11. Bb2 Ng6 12. Qd2 O-O 13. Rad1 Qe7 14. Qc1 Rac8 15. Na4 d5 (15... Bc6 { is safer} ) 16. Nxc5 bxc5 17. Rfe1 Rfd8 18. Ne5 Nxe5 19. Bxe5 Ne8 20. e3 dxc4 21. Bxb7 Qxb7 22. Qxc4 Rd5 23. Rxd5 exd5 24. Qg4 Rc6 25. Rd1 Re6 26. Bc3 Nf6 27. Qf5 (27. Bxf6 Rxf6 28. Qh5 Rd6 29. e4 g5 30. h4 d4 31. hxg5 Qxe4 32. gxh6 Rg6 33. h7%2B Kh8 34. Qxc5 Rxg3%2B 35. fxg3 Qe3%2B 36. Kg2 Qe2%2B 37. Kh3 Qxd1 38. Qf8%2B Kxh7 39. Qxf7%2B Kh8 $10) 27... d4 $2 {[right idea, wrong move order. It was better to play g7-g6 first]}  (27... g6 $1 28. Qd3 Ne4 29. Bb2 (29. Ba1 Kf8 $5 30. h4 Ra6 31. Qc2 g5 $5 32. f3 Qc7 33. fxe4 Qxg3%2B 34. Qg2 Qxe3%2B 35. Qf2 Qxf2%2B 36. Kxf2 dxe4 { unclear} ) 29... d4 30. exd4 c4 $1 31. Qc2 (31. Qxc4 $6 Nd2 32. Rxd2 Re1%2B 33. Qf1 Rxf1%2B 34. Kxf1 Qh1%2B 35. Ke2 Qe4%2B $10)  31... cxb3 32. axb3 (32. Qxb3 $4 Rb6) 32... Qd5 33. Bc1 a5 34. Qd3 (34. Bxh6 g5 35. Qc8%2B Kh7 36. Bf8 Qxb3) 34... Nd6 { and it is hard for White to make progress} ) 28. exd4 g6 29. Qf4 (29. Qc2 $16)  (29. Qd3 Rd6 30. Qe3 Kh7 31. d5 Rxd5 32. Rxd5 Nxd5 33. Qxc5 Nxc3 34. Qxc3) 29... Ne4 $6 (29... Qd5 { [White is only somewhat better]} ) 30. Bb2 $4 (30. Qf3 $1 Rf6 $4 31. dxc5 $3 Rxf3 32. Rd8%2B Kh7 33. Rh8#) 30... Ng5 31. dxc5 (31. d5 Nh3%2B 32. Kf1 Nxf4 33. dxe6 Nxe6)  31... Nh3%2B 32. Kf1 Qh1# 0-1">, <param name="flashvars" value="orientation=H&tabmode=false&light=f4f4fF&dark=0072b9&bordertext=494949&headerforeground=ffffff&mtforeground=000000&mtvariations=FF0000&mtmainline=000000&mtbackground=ffffff&pgndata=[Event "WCC"] [Site "WCC"] [Date "2014.11.29"] [Round "10"] [White "Nick Barr"] [Black "Michael Sole"] [Result "0-1"]  { I was playing Nick Barr and he played the Queen’s gambit. I was expecting this since this is what happened last game. The game finished at 11:45 and closely matched our last game. } 1. d4 d5 2. c4 e6 3. Nc3 Nf6 { Queen’s gambit declined main-line} 4. cxd5 exd5 { Exchange line} 5. Bg5 Nbd7 6. e3 Be7 7. Bd3 O-O 8. Qc2 h6 {First non-book move.    } 9. Bh4 b6 {This move helps prepare for c5 and Bb7. } 10. Nf3 c5 {This move challenges White’s centre. } 11. dxc5 Nxc5 {This is a nice outpost for the Knight. } 12. Be2 $6 {I feel that this move is not needed as the Bishop pair is not doing much here and that a developing move would be better. This move also gives up some pressure on the e4 square.      } (12. Rd1) 12... Bb7 { Putting more pressure on e4} 13. Nd4 { This is a nice place for his Knight and stays here for some time} 13... Rc8 { Grabbing the c file} 14. Qd1 $6 { Again I feel that this move is not needed as the Knight was protected by the b-pawn. This move could have been spent on castling }  (14. O-O) 14... Nfe4 {Getting a nice place for my knight and threatening NxNc3 and then after the recapture, Ne4 wins the c-pawn. The bishop is also under attack.  } 15. Bxe7 Qxe7 {I like this position for Black } 16. Rc1 {Stopping the loss of the c-pawn } 16... Nxc3 17. Rxc3 Ne4 {This gains the c-file for Black } 18. Rb3 {I thought about this move for around 10 minutes here deciding between Qg5 and Rc5} 18... Rc5 {I picked this move to wait for White to castle before moving the Queen as it is in a nice place to attack the Queenside   }  19. O-O Rfc8 {Further marking the c-file } 20. f3 $5 { This is the type of move I was waiting for as this weakens his king side and gives me a target to attack.} 20... Nd6 21. Ra3 { Attacking the a-pawn} 21... a6 {Setting a trap. }  22. Qd3 { This move gives me the very useful c4 square for my Knight}  (22. Bxa6 Bxa6 23. Rxa6 Qxe3%2B 24. Kh1 Rc1) 22... Nc4 23. Rb3 Re8 { Putting pressure on e3} 24. Nf5 $2 Qe6 $6 {This is not the best move to win the pawn Qf6 is better. }  (24... Qf6) 25. Kf2 $2 {This move does little to protect the pawn } 25... Bc8 { Attacking the Knight} 26. Nd4 $2 { This move loses the pawn.} 26... Qf6 27. Qd1 $2 { Losing more protection} 27... Qh4%2B 28. Kg1 {Losing the exchange} 28... Nxe3 29. Qe1 $4 { This loses the Knight} 29... Qxd4 30. Qf2 Nf5 $2 { While this move is winning Rc2 is better} 31. Rxb6 $4 { Re2 is fatal now} 31... Qxf2%2B $2 { Not taking the bishop}  (31... Rxe2) 32. Kxf2 $2 { giving the Bishop back} 32... Rc2 33. Re1 Nd4 34. Rb8 Rexe2%2B 35. Rxe2 Rxe2%2B 36. Kg3 { } 36... Re8 {Winning for Black } 37. b4 Nb5 38. a4 Nc3 39. b5 Bd7 40. Rb7 Bxb5 41. axb5 axb5 {Getting rid of the pawns} 42. Rb6 Rc8 43. Kf2 Re8 44. g4 Kf8 45. h4 Re2%2B 46. Kg3 Ke7 47. g5 hxg5 48. hxg5 Kd7 49. Kg4 Kc7 50. Ra6 Kd7 51. Kf5 g6%2B 52. Kf6 {I played the risky move of Re6%2B giving white promotion chances} 52... Re6%2B 53. Rxe6 fxe6 54. Kxg6 Ke7 $2 {I played this thinking that white would play Ka6 so my king could keep up} 55. Kh7 $1 { This move makes promotion a sure thing} 55... b4 56. g6 b3 57. g7 b2 58. g8=Q {He promotes first but I promote with check } 58... b1=Q%2B {Now I can swap Queens and queen my other pawns } 59. Qg6 { If the king moves then I can still swap}  (59. Kh6 Qh1%2B 60. Kg7 Qg1%2B) 59... Qxg6%2B 60. Kxg6 d4 61. f4 d3 62. f5 exf5 63. Kxf5 d2 { Black resigned here.} 0-1">

You can easy copy this. If you need you can make some performance on this text as well. If you need more help just let me know.


No, according to the tournament page; it is a Swiss.


Is today's chess.com daily puzzle a draw (as hinted at in the puzzle title)?

No, you are not.

It's an easy win for white as far as I can see.


Debugging my chess engine through the Arena GUI

Did you set she compiler / linker flags correctly? (/DEBUG in the linker, /Od and /Zi in the compiler - which flags did you set?) Is the pdb-file located in the same directory as the executable? You can also manually load the pdb after breaking in your code and see, if symbols appear. If not, look at the flags.

To avoid the "attach to process", you can also put a

  __debugbreak();

in your code. This also avoids any mishaps with choosing the wrong process to attach to.
I would probably put the break somewhere where the "uci" command is handled.

But both methods to attach the debugger are valid and should normally work.


Everything you have learned in classical chess but opening variations also applies in Chess960 : respective values of the pieces, king safety, development, center, activity, concrete calculations, open lines, pawn structure, endgame theory, initiative, etc.

All those concepts are essential to Chess960's strategy. This explains why the best Chess960 players are the best chess players: they don't need specific training or strategy to adapt to the game, as they would if they wanted to try bughouse or loser chess or 4-players chess.


How many positions per second can a modern supercomputer calculate?

To answer the question in the title: In chess programming, perft is used for debugging move generators and testing their performance: the goal is simply to calculate the number of possible ways the game could continue until a mate or a stalemate for the next N moves. Modern engines give around 10-100 million nodes per second using one core of a modern processor. This program apparently searches 20 billion nodes per second using a modern GPU instead of a CPU.

However, as I said in the comments, searching for a mate in N moves is very different than searching all possible moves until that depth. The following observation is the heart of alpha-beta pruning: for example, if you have found that after 6.Nc3 Qxb4 7.Nd3 white can mate, there's no need to see what happens after 6.Nc3 Qxb4 7.a4.
Another, perhaps more likely example: You have found that the position after 5.e3 is drawn, and then find out that 5.e4 Qc7 gives a draw, too. Now we already know that the position before 5.e4 is at least a draw for white, and find out that the position after 5.e4 cannot be a win for white. Because it does not matter whether white draws or loses after 5.e4, we don't have to see what happens after 5.e4 Qb6.
As you probably can see, move ordering is critical here: it is beneficial to search best moves first. In fact, with perfect move-ordering, alpha-beta can reduce the number of searched nodes to approximately square root of the original value. So with perfect move-ordering, the number of positions needed to search for mate in 10 plies would be 35^5, not 35^10. But to get a good move ordering, one needs to do something else than just generate moves: perhaps evaluate the intermediate positions to get a good hint of the values of the moves. Of course, for the search of mate in, say, 20 plies, the best evaluator function would probably be different than what is used in engines designed to play a full game of chess.


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


1. e4, 1. d4, 1. c4, or 1. Nf3? Which opening move has given the greatest scoring percentage for White in World Championship Matches?

1. b3 has the greatest scoring percentage (100%), although it's statistically insignificant because it only appears in one game out of 1,506.

The successful openings played more regularly are:

Nf3 (61.7%, 102 games)
c4 (59.3%, 129 games)
e4 (57%, 631 games)
d4 (55.4%, 632 games)

That data's compiled after downloading all 1,506 World Championship games from 1886 to 2013 from the chessgames.com WCC archive. Here's what Scid's Tree Window shows:


I would recommend the Yusupov-Series, in your case the first three books (orange), called Fundamentals.

There are a lot of books out there that you would profit from reading, but the Yusupov books are more of a trainings course and I believe that you generally get out of a book in (terms of Elo) what you put into it (in terms of effort).

Doing these exercises will give you actual practical abilities instead of just illusions of understanding.


The Albin Countergambit is not to be feared, particularly.  White does quite well after the simple 3. dxe5.  My chess database of master games shows that white wins or draws 80% of the games after 3. ... d4 which is Black's best response.

Now, before I go down the rabbit hole, please bear in mind that strong masters probably don't visit this site.  For amateurs, almost anything is playable.  In any of the games we play, a master could win either side on any move as long as the game isn't blatantly lost.  The moves are there.  So temper everything I say regarding what is and isn't playable.

This is one frequently played variation:

[fen ""]
1. d4 d5 2. c4 e5 3. dxe5 d4 4. Nf3 Nc6

It yields a generally fun time for White. Tese are, statistically, Black's best moves.  However, there seems to be a trap of sorts: 5. g3 is White's most common response but there are 7 games with the uncommon Black response of 5. ... Bg4.  From 7 master games, Black wins or draws 5.  I'd avoid g3 :-D

Here's a sample game where White did not.  Nathan Birnboim v. Itzhak Veinger, Munich 1987. ECO D09.

[fen ""]
1. d4 d5 2. c4 e5 3. dxe5 d4 4. Nf3 Nc6 5. g3 Bg4 6. Bg2 Qd7 7. O-O O-O-O 8.  Qb3 h5 9. h4 f6 10. exf6 gxf6 11. Rd1 Bh3 12. Bh1 Bc5 13. Nc3 Qg4 14. Na4 Bd6  15. Kh2 d3 16. Rxd3 Nge7 17. c5 Bxg3+ 18. fxg3 Bf1 19. Bf4 Bxe2 20. Rxd8+ Rxd8  21. Bg2 Kb8 22. Re1 Rd3 23. Qc4 Rxf3 24. Bxf3 Bxf3 25. Qe6 Qg6 26. Qc4 Bd5 27.  Qc3 Bxa2 28. b3 Qf7 29. Qd2 Bxb3 30. Qd7 Ne5 31. Qd8+ Nc8 32. Ra1 Qc4 33. Bxe5  Qe2+ 34. Kg1 Qxe5 35. Rf1 Qxg3+ 36. Kh1 Qxh4+ 37. Kg2 Bxa4 38. Rxf6 0-1

Everything looks normal until move 7, where Black's Queenside castling pretty much declares he's uninterested in a draw.  Such games are generally razor-sharp.  On move 8, Black announces he's uninterested in a long game.  He believes White's King's position is weak and he's exploiting it now.  9. h4 hurt my face. I had to invoke Stockfish which didn't have a huge problem with (or particularly like) 8. ... h5 9. h4. Stockfish didn't have a problem with 12. Bh1, either.  At move 12 White is ahead a little, but Black has chances.  Black's playing aggressively but White solves the problems. Stockfish didn't care for 13. ... Qg4 and considered 15. ... d3 a blunder.  If I can read the tea leaves, after move 15 Stockfish considers White up by about 2 pawns.

To this point Black has had the initiative and has aggressively posed problems for White. Both players have erred between moves 15-19 but White has increased his advantage to the point he'll probably win.

But a won game is sometimes hard to win! White starts to falter on move 24. Whites 24th, 25th, 26th, 28th, and 29th moves are poor.  Black plays well and erases White's advantage completely.  It's a horse race again!

So where are we?  on move 30, Black has a glaring back-rank weakness but the Knight on e7 protects c8.  White's Kingside pawns are slightly better but the backward g pawn negates most of the advantage.  White's Queenside pawns dropped like flies. Black's 3-to-1 advantage will eventually be worth a piece.  Black's Knights aren't aggressively placed but defend very well. Black's queen can rampage and is otherwise uncontained.  White's Knight is looking silly there on the rim but his Queen and Rook are well placed.  White's biggest problem is his exposed King.  While I couldn't foresee the position when he played 9. h4, I can't say I am surprised.  Black is always going to have a 'get out of jail free' card as long as Queens are on the board.  White will be better off if that Black Bishop is removed; the Bishop's mobility is devastating with the White king being so exposed.

White loses the game on move 32. Ra1 is a terrible blunder. Here's what Stockfish recommended instead.

[fen "1knQ4/ppp2q2/5p2/2P1n2p/N4B1P/1b4P1/7K/4R3 w - - 4 32"]

( I can't get the replayer to work: Here are the moves: 1. Nb6 axb6 2. cxb6 cxb6 3. Qh8 Bc4 4. Rxe5 fxe5 5. Qxe5+ Ka7 6. Qb8+ Ka6 )

We see White start a combination that culminates in the destruction of the Black King's safety.  White counters his biggest problem by sticking Black with the same problem.

Back to the main line, the ghastly 32. Ra1 sort of hits a7 while defending the misplaced Knight.  White loses tempos bigtime.  Black's 32. ... Qc4 is menacing in itself, but now we see the Knight on e5 is a monster.  If it makes it to g4, it's going to be lights-out for White. f3 a good square too.  White kills the Knight but then gets a demonstration of a Zwischenzug - an in-between move.  Instead of the knee-jerk recapture with the f pawn, Black checks with the Queen, snags the Bishop, and forks the Rook and g-pawn.
Black threatens something like 1. ... Qxg3+ 2. Kf1 Bc4#  When White prevents this with Rf1, Black scoops up both reminaing Kingside pawns then scoops up the Knight on a4.
  Brutal.

Backing waaaay up now, I'd choose a different move that 5. g3.

Instead, I'd consider the prophylactic (and most common White move behind 5. g3)  5. a3
Black's best response is 5. ... Nge7.  18 games featuring other responses yielded -0- wins for black.  Ouch.  This seems to be one of those cases where both players have chances but one side (in this case Black) has to play much better to achieve a good result.

The first 10 moves are straight out of theory; there was no deviation in the master games.

I'll present the last games to amuse us - I have no more time for running the engine or providing b-player analysis.

This is an ECO D08.  White is Anatoly Karpov and Black is Rustam Kasimdzhanov - two heavyweights, to be sure.  This encounter is from the Keres Memorial at Tallinn on January 8th, 2006.

[fen ""]
1. d4 d5 2. c4 e5 3. dxe5 d4 4. Nf3 Nc6 5. a3 Nge7 6. b4 Ng6 7. Bb2 a5 8. b5  Ncxe5 9. Qxd4 Qxd4 10. Bxd4 Nxc4 11. Nfd2 Nd6 12. a4 Nf5 13. Bc3 Bc5 14. e3 O-O  15. Nb3 Bb6 16. N1d2 Nd6 17. Nc4 Nxc4 18. Bxc4 Re8 19. O-O Ne5 20. Be2 Be6 21.  Nxa5 Rxa5 22. Bxe5 Bb3 23. Bf4 Rxa4 24. Rxa4 Bxa4 25. Ra1 Bb3 26. Bf3 Bc4 27.  Rb1 Bd3 28. Rb3 Be4 29. Bxe4 Rxe4 30. Rc3 Rb4 1/2-1/2

The game is blown wide open.  If Karpov can stand it, you can too.

Here are two more samples with the same 10 first moves.  The viewer may not show it but White wins both.

Fernando Peralta v Manuel Perez Candelario, Nov. 8th, 2006.

[fen ""]
1. d4 d5 2. c4 e5 3. dxe5 d4 4. Nf3 Nc6 5. a3 Nge7 6. b4 Ng6 7. Bb2 a5 8. b5  Ncxe5 9. Qxd4 Qxd4 10. Bxd4 Nxc4 11. e3 Nd6 12. Nbd2 Bd7 13. a4 f6 14. Be2 Ne7  15. O-O Nd5 16. Rfc1 c6 17. bxc6 Bxc6 18. Bc5 Nf5 19. Nb3 Nb4 20. Bb6 Bd7 21.  Bxa5 Nc6 22. Bb6 Be6 23. Nc5 Bxc5 24. Bxc5 Kf7 25. Rcb1 Na5 26. e4 Ne7 27. Nd4  Bd7 28. Nb5 Ng6 29. Nd6+ Ke6 30. Bg4+ 1-0

And one more.  Mihajlo Stojanovic v. Branko Tadic, March 12th, 2007.

[fen ""]
1. d4 d5 2. c4 e5 3. dxe5 d4 4. Nf3 Nc6 5. a3 Nge7 6. b4 Ng6 7. Bb2 a5 8. b5  Ncxe5 9. Qxd4 Qxd4 10. Bxd4 Nxc4 11. e3 Nd6 12. Nbd2 Bd7 13. a4 f6 14. Bd3 Bf5  15. Be2 Ne4 16. g4 Nxd2 17. gxf5 Nb3 18. fxg6 Nxa1 19. Bxa1 Bb4+ 20. Kf1 hxg6  21. Kg2 O-O-O 22. Rc1 Kb8 23. Nd4 Rh4 24. Bd3 Bd6 25. h3 Rdh8 26. Bxg6 Rxh3 27.  Nf3 R3h6 28. Bd3 g5 29. Rc4 Rd8 30. Bf5 Re8 31. Bc3 b6 32. Rg4 Reh8 33. Re4 Rf8  34. Nd4 Rh2+ 35. Kf3 Kb7 36. Ne6 g4+ 37. Rxg4 Rh5 38. Be4+ Ka7 39. Nxf8 f5 40.  Rg8 1-0


Is there any software that will print a .pgn file in scoresheet layout

Scid can export to pgn, LaTeX and HTML. During export you have the option ''Column style (one move per line)? Yes/No''

I just tried it and it works for all three export formats. That's for scid version 4.6.4 on linux.


There exists "Yafi", which use FICS chess server, where you can play bughouse :
https://play.google.com/store/apps/details?id=pl.mg6.yafi


Why was castling bad for white in this game, and engine strongly prefered trading queens?

Castling (9. 0-0) is not a very bad move. You still have a very solid advantage after it due to being a pawn up and having the better pawn structure (black's pawns on a7, c7, c6 are weak and vulnerable).

However you had a better move...

The pawn on c6 is hanging and you could have simply taken it. Both 9. Nxc6 or taking the pawn after queen trades (9. Qxd8 Bxd8 10. Rxd8) are good.

Taking the pawn after queen trades is better, because you will also exchange the knight later on for black's dark squared bishop (which is due to the pawn structure, the stronger piece).

For instance an almost forced sequence could be:

[FEN "r1bq1rk1/p1p1bppp/2p2n2/4N3/4P3/2N5/PPP2PPP/R1BQK2R w KQ - 1 9"]

9. Qxd8 Bxd8
10.Nxc6 Bb7
11.Nxd8 Rfxd8
12.f3

In the end white is left with two pawns up, a strong pawn structure and the better bishop.


Why doesn't white take after 8..c5 in the Grünfeld, Spassky variation?

9.dxc5? is a horrible positional blunder.

The Grunfeld for black allows white a big center, and his idea is to chip away at it, or force it to advance, and then chip away at it. That center controls a lot of nice squares, and is very desirable. 9.dxc5? by white voluntarily does what black is trying to achieve in a very bad way, and worse, it turns the Bg7 into a monster. In exchange for that, you cannot even keep the pawn as black can win it two ways. It is so bad that in 5099 games in the Mega 2020 database, no one has ever played it. In addition, the eval on Stockfish goes from about +.70 to -.67 instantly.

Black can win back the pawn with Qa5, but even stronger is 9...Nd7, and the N will have an incredible c5 square as its base. I have added notes to the following line regarding other positional advantages, so be sure to read them.

 [FEN ""]

 1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Bc4 O-O 8. Ne2 c5 9. dxc5? Nd7 10. O-O (10. c6 Ne5 $1 11. Qxd8 (11. cxb7 Qxd1+ 12. Kxd1 Bxb7 13. Bb3 Nd3 14. Be3 Rac8 15. Kc2 Rfd8 {There are a million ways white can play from here, but they are all losing and black is all over him.}) 11... Rxd8 {And the N gets to d3 with great effect positionally or this...} 12. c7 Rd7 13. Bb5 Rxc7 {With a huge advantage.}) 10... Nxc5 11. Qc2 Bd7 12. Rd1 Qc7 {And white has big problems down the c-file, the Bc4 is in danger (if black trades for it, the two bishops are a winning advantage in this open position), and the Ne2 is not even well-placed.}


What are good openings for White during a blitz game?

I think this depends very much on how strong you are.

That said, I had some success with the Ponziani. It is not the "best" opening, but solid, and many players don't know it and lose some time thinking about the next moves. The theory is easy, and there are several traps black can fall into (my favorite is when black takes the "unprotected" e4 pawn with the knight and you can fork it with Qa4+).

Generally it might be a good idea to play aggressive (e.g. Steinitz' Qh4 in the Scotch game) and to try to throw the opponent out of the book as soon as possible. Of course the opening must be still playable, and you need to know some theory.


What is the average length of a game of chess with only random moves?

I reran the script from the answer GloriaVictis linked.

For a twenty-five thousand games the average length was 357 ply.


Is the World Chess Blitz Championship for Robots going to be broadcast over the Internet?

Appears unlikely given it does not even appear that there's a website for the event, just press releases that were posted to weblogs like the one you linked too. Here's archival video of "Vladimir Kramnik vs Robot" for anyone interested in viewing the game play; just in case you thought a robot play a person is boring, watch the robot "attack" Kramnik, he almost loses his hand.


A pawn break is a pawn move designed to free the player's position.
Generally speaking, a pawn move is only called a pawn break when the moving pawn is on a file adjacent to two enemy pawns facing each other, and the pawn moves forward to the same rank as the player's other pawn.
Since a picture is worth a thousand words...
[FEN "8/8/8/4p3/3pP3/3P4/2P2P2/8 w - - 0 1"]

White can play either 1. c3 or 1. f4 and these moves would be considered pawn breaks because they attack a black pawn that is blocking a white pawn (the d and e pawns respectively).
1. f3, however, is NOT a pawn break because it does not attack an enemy pawn.  Similarly 1. c4 is not a pawn break, even though black could capture the pawn with 1... dxc3 e.p. and get to the same resulting position because again, it does not attack a black pawn.


I think Bronstein had the right idea in the Exchange Grunfeld against Boleslavsky in the 1st game of the 1950 candidates final. It costs a little material, but it's White who got the active pieces, while the center expanded.
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
[Event "Bronstein - Boleslavsky Candidates Playoff"]
[Site "Moscow URS"]
[Date "1950.07.31"]
[EventDate "1950.07.31"]
[Round "1"]
[Result "1-0"]
[White "David Bronstein"]
[Black "Isaac Boleslavsky"]
[ECO "D87"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "63"]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3
c5 7. Bc4 Bg7 8. Ne2 O-O 9. O-O cxd4 10. cxd4 Nc6 11. Be3 Bg4
12. f3 Na5 13. Bd3 Be6 14. d5 Bxa1 15. Qxa1 f6 16. Bh6 Qb6+
17. Kh1 Rfd8 18. Rb1 Qc5 19. Bd2 b6 20. Bb4 Qc7 21. Rc1 Qb7
22. Qb1 Rab8 23. dxe6 Nc6 24. Bc3 Ne5 25. Bb5 Rbc8 26. Bxe5
Rxc1+ 27. Qxc1 fxe5 28. Bd7 Qa6 29. Ng3 Qxa2 30. h4 Rf8
31. Qg5 Rf6 32. Qxf6 1-0


How does a GM calculate opening and how many moves in advance?

They don't calculate the common openings, they know them by heart, at least the main lines, and the possible refutations, should the opponent deviate from the main line.

For the less common openings, they might remember things not as deep as the often playable ones. Still, it's like 10-15 plys for something obnoxious and could be as much as 20-30 plys for the most common ones.


I'd explain nothing about openings to a 6 year old, except maybe something about using all your pieces (but it'll fall to deaf ears, most likely).

I assisted at a local school tournament recently, where players of about seven had a lot of trouble playing legal moves, or checkmating their opponent when being up almost everything. Checkmate is often not recognized and whole phases of the game had both kings in check...

The key point is that they must have fun, and they usually want to go on hunting expeditions with their queen. That is fine. It's a game, and they're six. My seven year old does not want to play games where she can't create new rules on the fly, period.

Once they ask, you can show something like the Italian and explain that it gets some pieces out. That is enough.

But please, show them lots of other things as well, up to move 3 or so (when they ask). I hate to see those kids matches that always start 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.d3 d6 5.Nc3 Nf6 etc because for both of them that's all they know. That makes the game boring, and the main thing should be to have fun.

I don't think concepts like "too aggressive" or "requires too much calculation" really apply to openings for six year olds...


EDIT:

I'm confident both Houdini and Komodo are in C/C++, the best language for speed optimization.
I'd be very surprised if they don't use alpha-beta/nega-max. This is standard in chess programming.
I don't know about board representation in Houdini and Komodo, but bitboard is good and fast. Stockfish uses that, and I think it's common for all strong engines.

ORIGINAL

Lot's of possibilities (I can't list everything):

How to prune/reduce the search tree?
How to evaluate a chess position?
What about quiescence search? Do you want to extend your search horizon?
Bitboard? Mailbox? How do you want to represent the internal board?
Multithreading support?
Programming language. C++? Java?
Operating systems optimisations such as large pages?

While all chess engines I'm aware of use alpha-beta/nega-max, their implementation could be significantly different.

No. They don't all use the same algorithm and the same evaluation function. Visit https://chessprogramming.wikispaces.com/Home, and you'll appreciate the complexity in chess engine programming.


From the FIDE rules (emphasis added):

9.3
The game is drawn, upon a correct claim by the player having the move, if:
a. he writes his move on his scoresheet and declares to the arbiter his intention to make this move, which shall result in the last 50 moves having been made by each player without the movement of any pawn and without any capture, or
b. the last 50 consecutive moves have been made by each player without the movement of any pawn and without any capture.

So it's 100 total plies, or "half-moves."


Using a check-preventing piece to protect the checkmating piece

Yes- if they captured your queen, then it would count as them going into check:
(from this, ironically listed as a "Related" question here)

Besides making sense, it's also explicitly stated in the rules of the
game:
3.9 The king is said to be 'in check' if it is attacked by one or more of the opponent's pieces, even if such pieces are constrained from
moving to that square because they would then leave or place their own
king in check. No piece can be moved that will either expose the king
of the same colour to check or leave that king in check.
Source: Laws of Chess on the FIDE site


Why is it allowed to request an increment in time trouble?

but that will not affect the game due to his/her hopeless position

Well, if your opponent has a hopeless position, they would be better off accepting the 'automatic' draw offer which is implied whenever you make this request: "This constitutes the offer of a draw."

Therefore, invoking this III.4 rule is only beneficial if you have a worse position and very little time left on your clock, which sort-of makes sense: especially in classical games, we want the stronger side to win on the board, not by simply moving their pieces around.

One of the strengths of this rule is that it's an objective rule. An older rule (III.5.1) is that the player in time trouble can claim their opponent isn't trying to win by normal means; validating this claim required a subjective decision by an arbiter. I had never heard of rule III.4; I wouldn't be surprised if once it's wider known, rule III.5.1 will be abandoned entirely.


No, this is not legal.
Not relevant since 1 is illegal.
Checkmate is a win and no moves can follow.
You go back to illegal move and correct if its a friendly game, I don't know what the official rules are for when a player makes an illegal move.


How are the ECO codes for chess openings assigned?

It looks to me like someone just went in order of these started with the b pawn, the c pawn, the d pawn, the e pawn, and then indexed those. and then went the other side and said these were responded to by the b pawn, the c pawn, the d pawn.

Naturally, there is a more sophisticated classification of the whole deal. ECO stands for the Encyclopedia of Chess Openings. As with all encyclopedias, it has volumes. There are 5 volumes: A, B, C, D, E. Note that these correlate to the range of eco's which is A00 to E99. In your example, there are 40 entries for the Ruy Lopez (C60 through C99).

Each volume is broken down into a type of openings designated by,

Volume A: Flank Openings
Volume B: Semi-Open Games other than the French Defense
Volume C: Open Games and the French Defense
Volume D: Closed Games and Semi-Closed Games
Volume E: Indian Defenses

and in general, the main eco codes break down into

A
White first moves other than 1.e4, 1.d4 (A00–A39)
1.d4 without 1...d5, 1...Nf6: Atypical replies to 1.d4 (A40–A44)
1.d4 Nf6 without 2.c4: Atypical replies to 1...Nf6 (A45–A49)
1.d4 Nf6 2.c4 without 2...e6, 2...g6: Atypical Indian systems (A50–A79)
1.d4 f5: Dutch Defence (A80–A99)

B
1.e4 without 1...c5, 1...e6, 1...e5 (B00–B09)
1.e4 c6: Caro-Kann Defence (B10–B19)
1.e4 c5: Sicilian Defence (B20–B99)

C
1.e4 e6: French Defence (C00–C19)
1.e4 e5: Double King Pawn games (C20–C99)

D
1.d4 d5: Double Queen Pawn games (D00–D69)
1.d4 Nf6 2.c4 g6 with 3...d5: Grünfeld Defence (D70–D99)

E
1.d4 Nf6 2.c4 e6: Indian systems with ...e6 (E00–E59)
1.d4 Nf6 2.c4 g6 without 3...d5: Indian systems with ...g6 (except Grünfeld) (E60–E99)

Source: http://en.wikipedia.org/wiki/Encyclopaedia_of_Chess_Openings


Can I hover my finger over a chess piece without touching it in a major chess tournament?

Hovering your hand over the pieces does not violate the touch-move rule, but it is bad etiquette and arguably violates the rule against annoying your opponent ("It is forbidden to distract or annoy the opponent in any manner whatsoever.", say the FIDE Laws of Chess, §11.5 in the 2018 edition.)
Here's the explanation given in Chess for Dummies:

Furthering the touch-move rule, a frequent cause of complaints is the hand hover. The hand hover occurs when a player positions his hand over a piece and leaves it there. The hand hover is a distraction, and you shouldn’t do it — so goes the warning by José Capablanca. You should never obscure your opponent’s sight of the board unless you’re in the act of moving, so don’t reach for a piece until you’ve decided to move it.


Playing slowly depends on the time format of the game, If you are playing a bullet time format and you play slow, then you will make very few moves and time will run out before you checkmate your opponent. If you are playing a 90mins game and you play fast, then you will probably get checkmated and spent the next 75 mins waiting for the next tournament round to start...
There are both merits and demerits of analyzing a position too much.
Consider below position
[Event "Bled-Zagreb-Belgrade Candidates (1959)"]
[Site "Bled, Zagreb & Belgrade YUG"]
[Date "1959.26.10"]
[Round "27"]
[White "Robert James Fischer"]
[Black "Mikhail Tal"]
[Result "0 - 1"]
[SetUp "1"]
[FEN "1q2kbr1/p3rp1p/8/1p6/8/5Q2/PPP3PP/R4R1K w - - 0 1"]

1. Qc6+ (1. Rae1) *

In the above position Fischer analyzed the position for a while, and had a move that could draw the game, he even wrote the move down (This may not be the practice today) but ended up playing a different move. Rae1 would have secured him a draw but the move he played Qc6+ cost him the game. So if he had not analyzed the game too much he would have drawn this game
I believe it is Magnus Carisen who said that sometimes he knows the move he will make but still analyzes the position even more on long games. For short games like blitz, if you know the move, make the move
Consider this position
[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "r5k1/5ppp/5b2/2R5/8/6P1/5PBP/6K1 b - - 0 1"]

1... Ra1+ 2. Bf1
(2. Rc1) *

Is there need to think about the next move? There are only two moves, one is just giving out a rook. If you are playing a blitz game for example and there is only one move possible, play that move
Some positions may require more analysis, consider the below position
[FEN "1r2k2r/p4ppp/2b3n1/1pRBB3/8/8/PP3PPP/5RK1 b - - 0 1"]

1... Nxe5 *

How does white continue? Depending on how complicated the position is, there may be need to spent more time.
Now what if you have too many options at your disposal?
[FEN "5r1k/ppbq1np1/2n1rp1p/8/2PP3N/2NBP3/2Q2BPP/R3R1K1 w - - 0 1"]

In a blitz game I take the 1st good option and make it but if I have time, I can think about the position


Well, if your statistics are accurate (and not just based off games you remember), then there are a few possibilities:

1) The 1300-1500 players you play in OTB in your area are overrated. Or

2) The 800-900 players online are underrated.

Also, if you think you're good at chess but are beaten by these players online, are they really beginners? Online ratings especially at a low level aren't always representative of playing strength.


Is certain opening determine relative pieces value

To some extent, yes. General rule: if certain opening/variant of opening will leads to open position, then bishops will be worth more than knights - and usually opposite in closed games.


Is there a root tree of openings based on response by Black and vice versa?

I think what you are looking for is something like
https://chesstempo.com/opening-training/
or
https://openings.chessbase.com/
In both cases, you can build opening move trees (either for White or for Black - you train/drill one side per tree) by picking moves for any given position and the site will automatically handle transpositions for you if you reach matching positions (one branch will then point to the other).
If you specifically look for a tree with "optimal y's": Sorry, but that is still up to a lot of debate.


Why doesn’t Stockfish evaluate this fortress as 0.0?

Depth 64 means 64 half moves, it includes moves both by white and black. It isn't close to being able detect draws by means of the 50 move rule (100 plies). Especially since that is only the depth of the deepest line in the search, and to conclude it was certainly a draw, Stockfish would have to look at a huge number of lines that all eventually draw by the 50 move rule.
Endgame draws like this are notoriously difficult for engines, they have no good way to judge "progress" in their calculations. There are some attempts being tried out but they aren't at the level of Stockfish yet.
This is why tablebases were invented -- huge databases of all positions with up to some number of pieces (7 at the moment I think). They give an immediate answer. This is a five-piece position and a Stockfish configured to use tablebases would immediately know it is a draw.


The Chess960 analogue in shogi, xiangqi, etc

For shogi and xiangqi, the answer is no. There is no analogue for western Chess960 in those chesses. Disclosure: I'm a decently strong player in all three.
The problems Fischer identified in those quotes you gave are that western chess favours the player with more opening preparation, and that there is no room for creativity. (Bear in mind that this is his own view as an insanely strong player who had reached the top level of the game back then.)
To answer the question from a broader context, I will give a little bit of history and cultural context to show why shogi and xiangqi, despite also suffering from the "dogma of opening theory", never arrived at randomisation of the start position as a solution - indeed, the opening theory is not even perceived as a severe problem.
(Also, I will keep the context to professional/master players; at the amateur level, really anything goes for openings in all of the chesses.)
Shogi
Opening preparation is indeed important at the top levels. Historically the game has progressed from slower, cautious buildups favoured in the 17th-19th centuries, towards the more modern, faster game of the mid-20th century to today.
There are very sharp openings where one/both sides start attacking early and both players must walk tightropes (e.g. New Rapid Ishida; yokofudori/Side Pawn Picker; some lines of Gokigen Central Rook).
There are openings that have been examined to great depths (60 ply, even 80 or more ply) and involve many move order subtleties (Double Yagura games; Bishop Exchange; One-turn-loss Bishop Exchange).
There are openings which have gone even further, to survive in the ecosystem around it. (Fujii System was analysed literally all the way to mate in some lines by its inventory, Fujii Takeshii 9-dan.)
But yet, in the middle of all this, there is still room for creativity and variety. By the 1990s, of the two main styles, Static Rook was seen as the superior choice over Ranging Rook. The great player Habu Yoshiharu sparked something of a renaissance by playing Ranging Rook as an upstart young challenger in a title match - and winning. Since then different Ranging Rook styles, and even double Ranging Rook games, have never truly fallen out of favour at the professional level, even when engines overtook humans and universally preferred Static Rook.
There is more than enough to analyse, and still more creativity to be had (especially in double Ranging Rook games) - there was not a need for randomised shogi. This is of course not even mentioning arguments from tradition - there is no way that one can redo national culture by randomising the start position.
(Oh, and yes, randomised shogi would heavily disrupt existing opening theory, at least with regard to concrete moves.)
Xiangqi
Even before I talk history, the simple logistics of it is that xiangqi pieces don't randomise well. The kings, advisors and elephants are bound to the few points they can leap to, and are almost worthless if randomly shuffled away; the cannon movement means that they also don't randomise well, since on the first move already captures may be possible.
Now the history. Again, opening preparation is important at the top level. This should be no surprise again, as top players do like to seek any advantage they can get.
In ancient times (think 800 years ago), xiangqi was thought to be a win for red, the first player - classical manuals do some analysis on opening traps and games for red to win with central cannon versus screen horses, or opposing cannons (either one).
Fast forwarding to more modern times, there was the same sort of status quo from chess and shogi at one point: it was thought that black had trouble neutralising red's initiative, and the only defence against a central cannon was screen horses. The theory debates in this flowed from the 1930s onwards in national tournaments in China, with multiple red and black setups tested in battle.
In the 1960s, Grandmaster Hu Ronghua decided to revisit a "busted" opening. Was the Fan Gong Ma defence for black really losing? With tons of effort into research and with sheer playing strength, GM Hu Ronghua managed to bring the dead opening back to life, winning big tournament games with it and drawing other masters to try it. Again, this brought forth another period of experimentation that has not quite died down; even today, masters are exploring more than ever other red openings than a central cannon, with more fertile ground waiting to be explored.


Could White have won this double rook endgame?

48.Kf6 should be winning. After say 48...a2, white goes h4-h5-h6 and something involving ...Rh1, Rxa2 Rxh6+, Kg5 followed by Re2 will lead to the Lucena position.

Much earlier on, I believe 31.Kg3 is winning, but it's also the best try by elimination: without an active king (which is the most important non-trivial factor in rook endgames), white won't be able to win with just his f- and h- pawns vs. black's h-pawn if he loses his a-pawn, and after Rg8 as happened in the game, white's own king is exposed to a perpetual. Black is doomed to passivity because his rooks are disconnected, and white can slowly capture the rest of black's pawns and/or get his king to e6 and promote the f-pawn.

P/S: 17.Re1 Kf8 18.Ba3+ Kg8 19.Rad1 followed by 20.Re7 looks crushing.


Beginner book that has endgame scenarios

BCE (Basic Chess Endings) by Fine was the one I used.  It is long out of print.  There are some  newer books but I can't say which of them might be good now.  Also online has the sort of info you want and would be easier to find what you think is good for you.


The pawn promotion is part of the move of a white pawn to the eighth (or for a black pawn to the first) row. So you move the pawn to eighth row and replace it immediately with a piece of your choice (except kings, pawns or pieces of the opposite color). You don't need to spend an extra move for the promotion.

If a rook can immediately take your new queen, well such is life … ;-)
Maybe promoting wasn't such a good move then ...


Are certain tactics always good or does it really depend on the game?

TL;DR - Winning material is usually good but it's checkmate that wins a game of chess.

In chess there is only 1 primary aim, to checkmate your opponent before she checkmates you. ALL other aims are secondary. Thus a good move is one that makes you more likely to checkmate your opponent before she can checkmate you. End of story.

However great though that be it doesn't always provide a whole load of practical guidance when sat at the board with the clock ticking louder and louder. Thus as players of the game we employ a number of secondary objectives that experience has taught us will, with a good degree of probability, lead to the primary objective above, e.g. control the centre, develop your pieces, force your opponent to make weaknesses, win material, with your extra forces checkmate your opponent - it's only the last that counts, the others are just useful, but often very useful, stepping stones to that end.

To get to some of the more specific parts of your post, yes, the vast majority of times winning material is a good thing. To use the military analogy you now have more soldiers than your opponent, and more soldiers in a war is generally a good thing. Here's an example from a game I played at the club earlier this week:

[White "Me"]
[Black "My Victim"]
[Result "1-0"]
[FEN "r3q1rk/pp2p1bp/3p1p2/3P1PnQ/2P1B2R/1P2B3/P6P/2R4K w - - 0 1"]

1.Bxg5 Qxh5 2.Rxh5 fxg5 3.f6 h6
    ( 3...Bxf6 4.Rxh7# )
4.fxg7+ Kxg7 5.h4 1-0

Why has my opponent resigned? Well ultimately it is because he believes I am a good enough player that one extra piece is enough for me, in the long run, to force checkmate against him. At the board he'll say "Oh, I dropped a piece to Ian so resigned", but this is really a short hand for the above - Checkmate is the ultimate aim in chess, all others are secondary.

However you are also right in saying that it does depend on the particular situation, and this is because while a great aim winning material doesn't win the game of chess, checkmate does. And thus occasionally a player will give up material because he or she thinks or has calculated that doing so will make it more likely that they will checkmate their opponent before their opponent checkmates them. Be very clear that this is the exception rather than the norm, but it's having to evaluate such possibilities that makes chess such a great game! As an example here's one of my favourite games of all time. Black gives up loads of material but it's all toward the end of queening one of his pawns, and with his new queen he will checkmate his opponent - and checkmate is how you win a game of chess!

[Event "Student Olympiad, Marianske Lazne"]
[Site "Marianske Lazne CSR"]
[Date "1962.07.??"]
[Result "0-1"]
[White "Eduard Gufeld"]
[Black "Lubomir Kavalek"]
[ECO "C64"]
[PlyCount "64"]
[FEN ""]

1. e4 e5 2. Nf3 Nc6 3. Bb5 Bc5 4. c3 f5 5. d4 fxe4 6. Ng5 Bb6
7. d5 e3 8. Ne4 Qh4 9. Qf3 Nf6 10. Nxf6+ gxf6 11. dxc6 exf2+
12. Kd1 dxc6 13. Be2 Be6 14. Qh5+ Qxh5 15. Bxh5+ Ke7 16. b3
Bd5 17. Ba3+ Ke6 18. Bg4+ f5 19. Bh3 Rhg8 20. Nd2 Bxg2
21. Bxg2 Rxg2 22. Rf1 Rd8 23. Ke2 Rxd2+ 24. Kxd2 e4 25. Bf8 f4
26. b4 Rg5 27. Bc5 Rxc5 28. bxc5 Bxc5 29. Rab1 f3 30. Rb4 Kf5
31. Rd4 Bxd4 32. cxd4 Kf4 0-1


Why is castling kingside more encouraged than queenside?

It's very difficult to answer without a specific position, but here are a few general thoughts:

Kingside

It is almost always faster to castle kingside because only two pieces need to be moved out of the way, and those two pieces have very natural squares (Nf3, Bb5/c4/e2).
The kingside pawns are usually left on their starting squares so the king is usually safer on the kingside than it would be on the queenside.  This is in part because the a file can be weak after long castling.
In many positions, the move c3 (...c6 for black) is useful to support a d4 (...d5 for black) push.  c3 is much safer after kingside castling.  After queenside castling, c3 makes the b1-h7 diagonal weaker.
After short castling, it is possible to push the a and b pawns to try and gain space on the queenside without making weaknesses around the king.  For example, the move a4 is frequently useful in the Ruy Lopez and the Slav.

Queenside

Usually white is the one to castle queenside because white gets to move first.  White can use the initiative to develop faster and start an attack.  Almost all opposite castling games feature white playing O-O-O and black playing ...O-O.
The biggest advantage of queenside castling is that the rook comes immediately to d1 (d8 for black).  This means that queenside castling basically saves a move over kingside castling (no need for Rfe1).
Often white will need to play Kb1 to better protect the king (black can play ...Kb8).  This is another tempo that must be "wasted" after castling long.
The king is often exposed on the c1-h6 diagonal because the d pawn is usually moved early in the opening.  Kb1 mitigates this danger, but this is still something that must be considered.

Additional Thoughts

If you want an attacking game, castling to the opposite side of the board than your opponent is the easiest way to do this.  The reason is that then the pawns in front of your opponent's king can be pushed forward to participate in an attack.
If you want a safe game, for example when your opponent has a lead in development, castle on the same side as your opponent.  If your opponent tries to push the pawns on the same side as the kings, you will frequently be able to counter-attack.
When in doubt, kingside castling is almost never "wrong", but queenside castling is sometimes a grave error.  In illustration, I present Boden's Mate:

[FEN ""]
[StartPly "28"]
[Event "simultaneous exhibition"]
[Site "Budapest"]
[Date "1934"]
[Round "?"]
[White "Esteban Canal"]
[Black "?"]
[Result "1-0"]
[ECO "B01"]

1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 c6 5. Nf3 Bg4 6. Bf4 e6
7. h3 Bxf3 8. Qxf3 Bb4 9. Be2 Nd7 10. a3 O-O-O?? {Incredibly, castling queenside turns out to be a blunder which at the least loses the queen. In another book, Reinfeld writes, "Black mistakenly thinks that [11.axb4] is out of the question. But White, seeing further ahead and relying on his excellent attacking position, has a stunning surprise continuation." Iakov Neishtadt writes, "Black is convinced that his opponent cannot take the Bishop. This would indeed have been the case if he had played not 10...0-0-0, but 10...Ngf6." Seirawan and Minev advise, "Motto: Think twice before castling on the Queenside!"}
11. axb4!! {If a6, b7, and c6 are unprotected by black pieces, then Boden's Mate would be possible, so White starts to deflect the black queen from guarding these squares by force.}
11... Qxa1+ {If Black plays 11...Qb6 in order to protect a6, b7, and c6, then (besides already being a piece up) White could continue to attack the black queen with 12.Na4 [12...Qxb4+? 13.c3 Qb3 14.Ra3], and the queen will run out of safe squares to protect a6, b7, or c6.}
12. Kd2! {Another deflection. Black is doomed now, for after capturing the white rook at a1, Black loses the last chance to protect c6, and the black queen is unable to stay on the a-file to protect a6.}
12... Qxh1 {Reinfeld writes, "Microscopically preferable was 12...Ne5 13.Bxe5 Qxh1 14.Qxf7 Rd7 (amusing would be 14...Ne7 15.Qxe6+! Rd7 16.Bg4 Rhd8 17.Qd6! forcing mate) 15.Qe8+ Rd8 16.Qxe6+ Rd7 17.Qe8+ Rd8 18.Bg4# !"}
13. Qxc6+ bxc6 14. Ba6# {[%draw arrow,a6,c8, red][%draw arrow,f4,b8, blue]} 1-0


Is online chess learning as effective as using books?

I have found that reading books makes one concentrate more, and the material is usually covered more in-depth. I think that the "in-depth" part of this is what is important. The explanations are usually much better, and geared toward learning something more permanently.

I find that my work on a famous chess site that you buy materials has been much more shallow. I can click, and it does not matter if I get it right since it shows me what I did wrong immediately. Instead, when I read a book, I really have to think hard since a book does not spit out the answer.

I also just found this Quora question, and the level of players answering is astoundingly high, and they all seem to agree that books are still the way to go.


Simltaneous checkmate and draw claim on the 50th move

The Laws of Chess say:

  9.3 The game is drawn, upon a correct claim by the player having the move, if

  a) he  writes his  move on  his  scoresheet  and  declares  to  the
  arbiter  his  intention to make this move, which shall result in the
  last 50 moves having been made by each player without the movement of
  any pawn and without any capture, or

  b) the last 50 consecutive  moves  have  been  made  by  each  player
  without the movement of any pawn and without any capture.

So you don't claim the draw WHILE you checkmate but BEFORE you make the checkmate move. Therefore there is no checkmate, but the game is drawn.

If you don't claim the draw but execute your checkmate move, your opponent cannot claim a draw by 9.3.b) because the game is finished by your checkmate.


How big is the advantage for white in the "back-rank-game"?

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


Aggressive Line against Alekhine's Defence?

Spielmann Gambit

[Event "?"]
[ECO "B02"]
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/ b - - 0 1"]

[Setup "1"]

1. e4 Nf6 2. Nc3 d5 3. e5 Nfd7 ( 3... d4 {Black dodges the gambit, resulting and open, even game with even material, which is quite satifying anyway, if you want to dodge Alekhine Defense theory} 4. exf6 dxc3 5. fxg7 cxd2+ ) 4. e6 {Spielmann Gambit! White gives up a pawn to disorganize Blacks pieces, and will try to keep Black disorganized as long as possible. White has also good attacking possibilities on king side.} fxe6
5. d4 g6 (5... e5? { Trying to free up immediately, but... } 6.dxe5 e6 (6... Nxe5? 7. Qxd5 {Black has no material advantage and white has better position}) { Black gave up his extra pawn for reaching this defensive position. Worthy? I don't think so. White has a good play without giving up material.} ) {I think this is the best move for Black here. Fianchettoing bishop would give black a nice control over black squares in the center. Also ...g6 move closes e8-h5 diagonal, which will be used by white queen in some variations}

This is my favorite and totally awesome for a white player who wants to get initiative and attack.

After 5.d4, white plays to maintain control of central black squares, avoiding blacks freeing move ...e5, not letting black to develop, and attack from king-side using f7. I won a lot of games with whites in this variation, most importantly I had great fun avoiding Alekhine opening and gaining an attacking position instantly :)

Bonus: You can reach the same position in Scandinavian Defense too! 1.e4 d5 2.Nc3 Nf6.

For all this reasons, this is a  very nice variation to put into repertoire as white.

However, black can dodge White's gambit by 3... d4, which results with even, open game. But anyway, Alekhine is avoided.

Notes about edits: I'm trying to add more analysis and more variations as you ask in comments, but it's really hard to cover all the analysis details in here. I also know there is not much material out there to study this gambit, so I'll do my best to cover as much as I can in my spare time.

Less preferable alternative

[ECO "B02"]
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/ b - - 0 1"]
[Setup "1"]

1. e4 Nf6 2. Bc4 Nxe4 3. Bxf7+ Kxf7 4. Qh5+ Kg8 ( 4... g6 5. Qd5+ e6 6. Qxe4 )
5. Qd5+ e6 6. Qxe4  *

If you opponent is greedy enough, you can go for this, but I don't like resulting position as white, I would prefer black side, so I didn't ever play this. Anyway, this is an option.


Well-annotated books for average players

I'd direct you to NM Dan Heisman's recommended reading list, specifically his Recommended Instructive Game Anthologies section.


Between most players, Elo ratings are zero-sum.
The formula for updating an Elo rating looks like this. Suppose player 1 and player 2 are playing a game. First, their ratings are used to generate a prediction: an expected score W that player 1 will get against player 2. Then, we compare this to the actual score, X. player 1 will get K*(X-W) points, where K is a "development factor" - more on this later on.
From player 2's point of view, the expected score is 1-W and the actual score is 1-X (a score of 1 for player 1 means a score of 0 for player 2, and vice versa). So player 2's rating changes by K*((1-X)-(1-W)) or K*(W-X) points, which is the negative of player 1's change. Zero-sum!
The development factor K is the only thing that can break this. In the FIDE version of the Elo rating system, this value is 20 for most players, but it's 40 for new players (to represent the uncertainty in their rating) and 10 for players that have ever had a rating over 2400 (for the opposite effect). If two players from different categories play, then the result will not be zero-sum.
Also, globally, the sum of ratings does change, because players are leaving and entering the pool. A new player starts with an Elo rating determined by their first few games, adding to the supply. That rating may become larger or smaller by the time they stop playing chess for whatever reason - removing another number from the supply.


For team events, what is the correct way to record a player's team in PGN format?

There are two fields I have seen used extensively for this purpose: WhiteTeam and BlackTeam.

They don't appear to be documented in the PGN Standard, but don't let that discourage you.

As one example, I have found these fields present in the Olympiad 2016 Baku PGN games download file. They are also present in any PGN file created from a MegaBase database for a team tournament. They are also included in every PGN file published by The Week In Chess (TWIC) by Mark Crowther and by ChessBase Magazine, such as the World Team Championships, the French, Swedish and Hungarian Team Championships, the United States Chess League, the European Club Cup, and so on.

This means they are populated by publishers of game scores, and also that they are stored in a CBH-format database. The PGN handler for ChessBase will both export and import these fields within the PGN data.


In this case, one tempo is important due to the concrete nature of the current position. White doesn't have to use it to play Nf3:

4.e3 Bxc3 5.bxc3 c5 6.Bd3, and if Black plays in the style of the Huebner with 6...Nc6 then White has 7.Ne2! and now 7...d6 8.0-0 e5 9.Ng3! gives White an edge (Stockfish says around +0.60). His knight controls the key e4- and f5- squares, and an f4 push is coming soon. This position is a major improvement for White over the normal Huebner system, where instead of playing Ne2-Ng3, White plays Nf3-Nd2 (to avoid Black's threat of playing the ...e4 fork). A knight on g3 can become an active attacker on the kingside, while a knight on d2 just blocks in the c1-bishop.

Note that if Black refuses to play in the style of the Huebner (6...Nc6, 7...d6, 8...e5) then White plays an early e4 push and gets a crushing position in the centre.


What are the quckest helpmates delivered by the rook, knight, bishop, and pawn?

Here's what I came up with.

Bishop took me 3 moves:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1.e4 f5 2.Be2 g5 3.Bh5#  *

Knight took me 3 moves as Black:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1.e4 Nc6 2.Ne2 Nd4 3.g3 Nf3#  *

Pawn took me 5 moves:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1.e4 Na6 2.Bc4 Nb4 3.e5 Na6 4.e6 Nc5 5.exf7#  *

Rook initially took me 6 moves, with 1.h4 f5 2.Rh3 f4 3.d4 f3 4.Rxf3 g6 5.Bh6 Nc6 6.Rxf8#. But I found a quicker way to checkmate with a rook - promote to one! This results in a checkmate in 5:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. g4 Nh6 2. g5 g6 3. gxh6 Bg7 4. hxg7 Na6 5. gxh8=R#


Giving up a knight and bishop for castled rook and pawn

This whole sequence is bad for white.  The minor pieces are stronger at such an early stage of the game.  White has virtually no development, while black now has more development and tempo.  Almost any player should value 2 pieces over 1 rook.  Just continue developing instead of the overly optimistic Ng5.

This may be acceptable in the dilworth attack or Open Ruy Lopez where black sacrifices 2 pieces for a rook on f2


Stockfish crashing on checkmate positions, and erroneous evaluation

Everything works perfectly.

You should add 50 move counter to your FEN, but this is not the biggest issue.
The eval command returns a static evaluation of your position. It doesn't start the search, that's why Stockfish gave you back the results immediately.

Try this:

ucinewgame
position fen rnbqkbnr/pppp1ppp/8/4p3/6P1/5P2/PPPPP2P/RNBQKBNR b KQkq - 0 1
go movetime 1000

The engine gives you back mate in one:

info depth 126 seldepth 2 multipv 1 score mate 1 nodes 3781 nps 945250 tbhits 0 time 4 pv d8h4


What is the idea behind playing 6.a3 in the Sicilian Najdorf?

The move a3 serves basically two functions:

White can develop the bishop to c4, and keep it aimed on d5, even if Black attacks it with b5, or, as Giri did, with Be6. In the lines where Black plays ...e5, the battle for d5 is often very important so it could be worth spending a tempo in it.
Black often plays b5 to gain some space on the queenside. The move a3 then discourages a further advance of the pawn to b4.

Another reason to choose this line could be that the main line is heavily analyzed, beyond the 20th move, and the White players didn't want to engage in a theoretical battle. This would especially apply to Carlsen who often plays 'sidelines', and this tweet from Karjakin confirms it as well:

  The only reason why I played 6.a3 against @anishgiri is that I forgot adaptor for my laptop and I urgently had to create a new ideas

Thanks @DagOskarMadsen and @DavidRicherby for drawing my attention to this tweet.


Has there ever been a game where multiple humans play against a single chess computer?

Six months ago a match was held on ICC: Komodo, one of the strongest engine, faced hundreds of people combined. Komodo won.

http://www.chessclub.com/article/icc-vs.-komodo-online-voting-match


According to official FIDE rules, when queening a pawn, can you pause the clock?

You may stop the clock if the piece that you wish to promote to is not at hand:

  6.12.b. A player may stop the chessclock only in order to seek the arbiter’s assistance, for example when promotion has taken place and
  the piece required is not available.


Most games published for human study are written in short algebraic notation.  For each move, the destination square is always specified, the moving piece is specified unless it's a pawn (in which case the origin file is specified for captures only), and if there's any ambiguity the origin rank and/or file is given to resolve it.  Captures are indicated by inserting 'x' before the destination square.  Promotion is indicated using eg. "=Q" suffix.  Additional suffixes are used to indicate check, mate, and move quality.
Long algebraic notation is just like the above, except that the origin square is always exactly specified, and usually a '-' is inserted in place of the 'x' for non-captures.  So Re1 might become Ra1-e1.  The same suffixes are used, and castling is still specified using O-O type notation.
English descriptive notation is somewhat more arcane, and may specify only the piece identities if the resulting move is unambiguous, eg. RxB.  It is now considered obsolete, though you might find it in old literature.  I don't think it is used in any engine protocols.  The same goes for foreign-language piece name abbreviations, eg. German chess uses Springer (S) instead of Knight (N).
The UCI protocol uses none of the above notations, but merely specifies the origin and destination squares; the only suffix is a single letter to disambiguate pawn promotions.  So exd8=N in short algebraic would become e7xd8=N in long algebraic, but e7d8n in UCI (all in lowercase).  Castling is specified by moving the king two spaces (in standard chess) or onto the corresponding rook (in 960) instead of in shorthand notation.


For White, which variation of the Queen's Gambit Declined tends to lead to the most solid, positional, slow, closed, quiet and strategic positions?

The fact that you would consider opening Nf3 suggests that you are open to openings like the Reti. The Catalan g3 leads to (somewhat) this kind of opening, albeit with a pawn on d4. More to the point, with the light squared bishop on the long diagonal, it appears to be an opening of the slow, steady, quiet variety that you favor, keeping White's strategic advantage for as long as possible, at least until you make a mistake, or Black outplays you.

The other variations, with the black-squared Bishop, do have the advantage of developing a new piece, but they are also more "tactical" and lead to earlier conflict. If I understand your question correctly, that's precisely what you want to avoid.