EXTENDED New Year's Math Riddle: 5-fold repetition & 75-move rules

Answers to all 4 questions

Q1: Under the 3-fold repetition & 50-move rules, how many times can a diagram occur?

A1: Even if it were mandatory, the 50-move rule has no impact: the answer is still 22 as per Rewan's post:
   2 (occurrences without triggering the draw)
 x 2 (White or Black to move)
 x 5 (number of castling rights intact: 4->3->2->1->0)
= 20
 + 1 (en passant)
 + 1 (the final 3rd occurrence)
= 22 times

There are 21 transitions between the 22 occurrences, each taking at least 2.0 moves which gives 42.0 moves. Also we must flip sometimes between White & Black having the move, which takes an extra 0.5 of a move each time to triangulate. If White were to move in the first, the player to move in each of the 22 critical positions is:
W-WWBB-BBWW-WWBB-BBWW-WWBB-B

Five 0.5 flips give a total of 42.0 + 5 * 0.5 = 44.5 moves.
Note that we require a diagram where parity can be switched by a free bishop or queen, as knights can't triangulate, and kings & rooks are tied up with castling rights. Rewan's diagram is sufficient for this, in order to achieve the 44.5, and in fact we still have a little slack and could waste another 5.0 moves. Because of e.p., the move prior to the first occurrence of the diagram was a pawn move, which zeroed the 50-move clock. For definiteness, let's say that the maximum is 49.5, to avoid draw by repetition and 50-move rule on the same move.

Q2: Under the 5-fold repetition & 50-move rules, how many times can a diagram occur?

A2: One might think that the answer is 42:
   4 (occurrences without triggering the draw)
 x 2 (White or Black to move)
 x 5 (number of castling rights intact: 4-3-2-1-0)
= 40
 + 1 (en passant)
 + 1 (the final 5th occurrence)
= 42 times

But in fact the diagram can only occur 37 times now, not 42.
There are 41 transitions between the 42 critical positions. Each takes at least 2.0 moves, which takes 82.0 moves, together again with the 2.5 moves for parity switching so that the player to move in each of the 42 critical positions is:
W-WWWWBBBB-BBBBWWWW-WWWWBBBB-BBBBWWWW-WWWWBBBB-B

84.5 moves would be needed, but the game will end at 75.0. So how many occurrences of the diagram can we get before we bring the game to a close by 5-fold repetition, before the 75-move rule ends us? If our budget is 74.5 (or even 75.0) moves, so we must eliminate 5 recurrences.
It takes us 74.0 moves to reach the diagram for the 37th time. By skipping the en passant threat at the beginning, we can reach the position more quickly.
BBBB-BBBBWWWW-WWWWBBBB-BBBBWWWW-WWWWBBBB-B

Q3: Find a 3-critical diagram that is a unique shortest proof game to its first occurrence.

A3: PG in 3.5. The last move to reach this position for the first time is a pawn move, as we then launch into the full 44.5 move sequence.
[FEN "r1bqkbnr/pppp1ppp/n7/8/4pP2/8/1PPPP1PP/RNBQKBNR w KQkq - 0 1"]

Q4: Find a 5-critical diagram that is a unique shortest proof game to its first occurrence.

A4: Proof game in 2.5 moves to a diagram which can occur 37 times.
[FEN "rnbqkbnr/1ppp1ppp/B3p3/p7/8/4P3/PPPPNPPP/RNBQK2R w KQkq - 0 1"]

This will take us 84.5 - 10.5 = 74.0 moves, which is perfect because White's 3rd move to reach the diagram for the 3rd time is not a pawn move or capture. So the game does not end prematurely by conflated draws by 5-fold repetition & 75-move rule.


How long to get a 200 rating point increase from serious chess study alone according to this academic paper?

The first paragraph of the RESULTS section on p. 155 says

  We applied log-10 transformations to three variables (cumulative study alone, cumulative tournament play, and chess book library size) prior to correlation and regression analyses.

The log-10 (logarithm base 10) of a number is what power you have to raise 10 to in order to produce that number; e.g. log 100 = 2, log 1000 = 3, etc.

So the sentence

  each log unit of serious study alone yields about 200 rating points

means that, all other things being equal, if player A studies ten times as long as player B, his rating will be about 200 points higher. (Another student who studies a hundred times as long as player B will have a rating of about 200 points higher than player A.) So there is no constant time span per 200-point gain; the required time to gain a particular amount of rating improvement gets larger and larger as you improve. (Another way to put this is that chess study produces diminishing returns.)

(In a sense, the Elo rating system is logarithmic as well, so you could claim that the relationship between study time and playing skill is actually linear. But since everybody measures playing skill by Elo rating, that's not so productive.)


What are the key ideas for white in the Keres Attack (Sicilian Scheveningen)?

OK, this one was tough to crack!

I almost gave up, but I believe I have found enough resources to help you grasp the concept of play.

  What are the key ideas for white in this variation?

I think that you will find the answer you seek in this article. The second part is found here and contains relevant moves only-no additional explanations are added.

Still, it tells you enough to grasp the basics.

  Should the King always castle queenside?

Yes, otherwise what is the point of g4-it will only weaken the king right ?

  Where should white place the light and heavy pieces?

According to the first part of the above article, bishop goes to g5, the other one's placement depends from the concrete lines, the way I see it. Rooks go to d1 and g1/h3-the latter depending on the circumstances.

  What setup should white aim for?

The second part of the above article has a good theoretical coverage in my opinion, but ultimately the decision is yours since I am not an 1.e4 player and my theory knowledge is too rusty.

As member Fischer suggested, you can use this link to see some master games with commentary and try to learn something from them. Here is the link with some instructive games, in my opinion, that might help you-note the reference to this game in the comments.

NOTE: Not all the games are about Keres attack but please observe that this is a blog, not a theoretical book.

Another reason for including these links: Being FIDE master yourself, and those guys being IMs, you should have easier time understanding their moves and you should improve faster from those games.

This article mentions several key games for illustrating themes and ideas in Keres attack. To see them you need to register, but with some cleverness we can bypass this:

We know that the games mentioned were played in year 2007 or before, and know the names of the players and the ECO code of the opening. With these information it was not hard for me to find referenced games:

Sokolov-Nisipeanu ( notice that this blog mentions e5 as serious novelty for Black as well-see the commentary bellow the diagram! )

Searching through the same database I found only one game between Macieja and Kasimdzhanov where they played Keres attack so here is the link.

And here is the last game.

These illustrate key ideas for black and ways the White copes with them-positioning of the rooks and minor pieces. For the original commentary of those  you shall have to get by yourself.

A good thing would be to compare the moves with the current theory, and to use strong engine to analyze the critical middle-game positions in order to reveal the mistakes players made. This should give you better insight about minor piece/rook positioning.

EDIT:

There are no "typical plans" or "typical piece setup" in the Keres attack-only raw calculation and creativity.

You must be able to adapt to the every change in the position-which is logical-since these are open/semi-open games and that is the quality they require from a player.

Only closed/semi-closed systems can give you "typical plans/piece setup" which is logical when you think about it, since the closed nature of the position allows you to maneuver.

In open games things change rapidly, so to ask "typical plans" is pointless, especially in such a dynamic and sharp line like this. I would focus my attention on tactical sharpness.

The way I see it, you can use g4 to force Black into making a concession on the king side and to grab more space. Then you should use your better piece coordination and space advantage to increase your initiative. Playing through the games I see this idea for White over and over.

This is the way I would approach this problem.

END OF EDIT

Unfortunately this is all I can offer at the moment, hopefully it will be enough.

Good luck and best regards!


Is it legal to push the rook with the king when castling?

As long as you -

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

then it is fine.


What strategic plan, for the White player, needed to implemented in the middlegame?

If you look at the position round about move 20 you see that you are already strategically worse. Black has a very good bishop and you have a very bad one thanks to your pawns on c4 and d5. Your pawn on c4 is much weaker in the endgame than black's on e7. You have set up the conditions for black to launch a winning minority attack on the queenside which he eventually did.

Your best chance at that stage in the game was to launch your own kingside attack. To that end you needed to keep pieces on the board and not swap them off as you did. On move 19, instead of g4, double rooks on the e file starting with Re3, then push your f pawn to break open his kingside. His pawns on d6 and e7 form a block making it difficult for him to bring his queen and a8 rook over to the defense. That should give you good chances of winning on the kingside before he wins on the queenside.

As it was you swapped off into a losing endgame.

Going back further in the game you can see that your pawn push to d5 set up the conditions for his win. In that kind of position you should be looking for the e5 push instead. If you can make that work then you will be much better.


Why do chess engines sometimes miss good moves (or take forever to spot)?

Why do chess engines fail to spot good moves in some positions?

The reason are called forward pruning techniques (see http://chessprogramming.wikispaces.com/Pruning)
with ProbCut in first line.

The move 15...Bf2 is pruned on shallow deeps because it includes the sacrifice 16.Rxf1 without regaining something concrete with evidence immediately after.
The matenet is also hard to see, because it includes some further 'silent' move
as for example 17...Ke7, and yes also engines, not only humans have difficulties to see distant silent moves as they are often pruned.

In this concrete case you even cannot say, that engines fail to spot good moves,
because also the continuation 15...Rh3h1 is a very good move and leads to an absolutely won position.

Last but not least you have to remember, that an engine's strength is always measured in terms of elo-strengh and not in the ability to find the absolute shortest way to win.
It does not matter, if a engine wins in 8 moves or in 25 moves.
Seeking to much for the shortest win, would mean a waste time, because most time there does not exist such a secret good move at all. And waste of time would hurt the engines ELO-Rating.


Skills required for blitz/bullet vs. correspondence chess?

While the two are vastly different, if you improve at one, you will most likely also improve at the other.

Tactics are far more important to get right in correspondence chess.  The slightest misstep will be punished by your opponent simply because they have all the time they need to analyze all of the variations, and they can also use at least a board to assist them, and in some cases, even a chess engine.

In blitz chess, while attacks frequently win the game, unsound moves are not always refuted.  This means that if you are able to launch an attack, even at the cost of a piece, your opponent will most likely be forced to burn time in order to avoid mate, and this will give you an advantage on the clock.

In terms of long term planning, in correspondence chess, assuming a high level game where tactical blunders will not determine the result, plans become incredibly important.  A correspondence game is frequently a battle between two plans while in blitz chess, tactics and the clock rule the day.

So overall, correspondence chess is a much higher quality game.  Blitz chess is fun and quick (so you can play a lot more games), but in terms of getting better at chess, blitz won't really help you.  If you want to improve at blitz, practice tactics and play more blitz!


Easy variation to learn with White against Semislav with not many lines and avoiding the Slav at the same time if possible

The easiest to learn is the exchange variation.  It leads to the persistent opening advantage, but doesn't offer much opportunity for a crushing win.  This is the line I played when I had to face the Slav.

[FEN ""]

[White "?"]
[Black "?"]

1. d4 d5 2. c4 c6 3. cxd5 cxd5 4. Nc3 Nc6 5. Nf3 Nf6 6. Bf4 Bf5 (6... a6 7. Ne5)
7. e3 e6 8. Bb5 Rc8 9. Qa4 Nd7 10. Bxc6 Rxc6 11. Qxa7 Qc8 12. Qa5 Ra6 13. Qc7
Qa8 14. O-O Bd3 (14... Rc6 15. Nb5) 15. Rfc1 Rc6 16. Nxd5 exd5 17. Rxc6 bxc6 18.
Ne5 Nxe5 19. Qxe5+ Be7 (19... Kd7 20. Qc7+ Ke8 21. Rc1) *


What was Caruana's plan in playing c6 against Carlsen in Game 10 of the Clutch Chess International?

If White goes for 11.Nc7+, then Black can reply 11...Kd8 Nxa8 Nxc1, however if Black played 10...Nxc1 directly, 11.Nxc7+ would win an extra pawn.

Note 10...c6 Bxe2 cxd5 would have been OK for black.


As a beginner, how do I learn to win in "won" positions?

There are two key things you need to do.
The first is to know how to win a won endgame. You do that by studying endgames. That will do two important things for you. Apart from teaching you how to win a won endgame, it will also teach you to recognise which endgame positions are won, and which are drawn, despite your material advantage. That way when you are in a winning middlegame you know what kind of endgame you are aiming for.
The second really important thing to do is to keep on fighting. The aim is not to get a winning middlegame position, it is to win the game. To that end a winning middlegame position is just one stop on the way to your real desired destination.
If you are driving to visit friends or family and you stop two thirds of the way there for petrol (or gas if you live in the US) you don't stop because you think you have arrived. You carry on after the stop, in just the same way as you did before the stop, except that you are no longer worried that you are going to run out of fuel (or not win the game).
This tendency to sit back once you have a theoretically winning position is something which affects all players. You have to fight it by trying even harder to not let your opponent back into the game and to win it yourself. Perhaps one good way of doing this is by starting each think about your next move by asking yourself "Why did my opponent do that? What are they trying to do? How can I stop them?"


In my opinion this is a pretty hard question to answer, because there is no single correct answer to it.

The choice of opening repertoire for a player should be determined by his play style, e.g. do you prefer to be aggressive always on the offense or are you more of a tactical player, looking for strategic weaknesses in your opponent's position, do you prefer closed over open positions, etc.

So my answer to your question would be to follow the basic principles of opening play:

control the center;
develop your minor pieces to their best squares;
get your king to safety;
do not move a single piece too often in the opening, unless there's a pretty good reason to do so;
do not bring your queen out too early.

From there on pick an opening that fits your play style and study the ideas behind it, not just memorize the moves, understand what each of them accomplishes.

  Are there any viable openings for white other than d4/e4, these seem
  overused and very cliche

These opening moves are most certainly not cliche. Although you might see these moves as the first move in almost every game there are lots of variations that follow. Therefore my recommendation for you would be to play an opening from the family of The Italian Game as White and maybe The French Defense as Black.

From my experience as an amateur I came to the conclusion that one shouldn't focus too much on openings. After you pick an opening that fits your style, focus on the endgame and various tactics and strategic ideas. This seems to be more efficient in the long run.

Good luck!


Two conditions must apply for a position to be checkmate:

The player to move has no legal moves.
His king is in check.

The first is true here, but the second isn't, so it's not checkmate.

When a player to move has no legal moves but isn't in check, it's called stalemate, and it's an immediate draw.


What to do if opponent has poor hygiene?

According to Article 12.2.3 of the FIDE Laws of Chess it is one of the roles of the arbiter to -

  12.2.3 ensure that a good playing environment is maintained

Your first course of action should be to bring the matter to the attention of the arbiter. It is not a pleasant thing for him or her to deal with but it is part of the (usually unpaid) job of the arbiter to resolve such problems.


Where can I find the live standings of the Grand Chess Tour?

On the London Chess Classics website, there is a link to the GCT Estimated Standings

An estimate is the best you can get though:

  ... The points actually allocated will be determined by tiebreaks which cannot be calculated until the end of the tournament...


What is the record for the most stalemates in one?

I managed to find the ultimate records in the Die Schwable Chess Problem Database.

[Title "Anthony Stewart & Mackay Dickens, Feenschach 9/1969, 113 Stalemating Moves"]
[FEN "6R1/PPPPPP2/7R/1K6/2N1BN2/2B4p/P4P1k/3Q4 w - - 0 1"]

Source Page

[Title "Anthony Stewart & Mackay Dickens, Feenschach 1/1969, 211 Stalemating Moves"]
[FEN "4Q2R/1K4Q1/3Q4/Q4Q2/2Q4Q/4Q3/1Q4Rp/1N1BB1Nk w - - 0 1"]

Source Page


You're likely looking at premoves; the players know (or at least have a good guess at) what their opponent's move is going to be, so they can already 'ready' their own move by taking the piece and dropping or just moving it to the destination square. Of course, if the opponent makes another move, they have to cancel their move (if it's still possible; that depends on the client, and whether they're dropping or just moving) or they might make a huge blunder.

Premoving can lead to funny things like the following:

[FEN ""]
1. d4 d5 2. Bg5 e6 3. Bxd8

Here, Black expects White to play a Queens Gambit with 2. c4, which is the normal move. If Black premoves 2... e6 and notices the 2. Bg5 too late, they will lose their queen.


Fritz allows null move entry via CTL+ALT+0. There may also be a menu option to do this.

Scid vs PC also allows this by capturing one king with the other or by using the keyboard to enter "--" i.e. hit the minus key twice.

Hiarcs also uses king takes king to enter a null move. There is also a menu option "Insert/Null Move" in the "Edit" menu, plus a keyboard shortcut of CTL+0


How are chess engines able to rank a Mate in X above a Mate in X+Y?

Engines don't use "infinity", usually they provide the value of position in centi-pawns, a queen will cost about 1000 centi-pawns and the price of the king is something about 30000 centi-pawns. When you are close to the mate, you get the evaluation at around 30000 minus about 1 queen for every move to reach the mate, to make it reasonable to sacrifice the queen for delaying the mate.

"mate in 1" becomes 29000, "mate in 2" becomes 28000 an so on, so engine has quite clear picture which move to make.

And reaching "mate in 10" only makes the engine to prune all branches that evaluate in anything less valuable, so "mate in 8" still stays on the table.


Playing against 1.d4 a similar pawn structure to the Colle, but with reversed colors for black, leads to a defense known as the semi-Slav:

      [FEN ""]
      [Title "The semi-Slav"]
      1. d4 d5 2. c4 c6 {The Slav defense to the Queen's gambit.} 3. Nf3 Nf6 4. Nc3 e6 {The semi-Slav defense to the Queen's gambit.}

The main characteristic of said structure are the pawns on c6, d5 and e6, mirroring the ones on c3, d4 and e3 that characterize the Colle-like systems. The standard development for black also follows the general guidelines that are common in the Colle, that is, Bd6, 0-0 (although in some variations this move is delayed), Ngd7 and e4 when allowed.

This defense is a very well respected one, and it has been used as a drawing weapon by Viswanathan Anand many times. It has the drawback of needing a huge amount of theory in order to not fall behind in development and getting a passive position out of the opening. Players willing to play this need to have patience and accept playing in an somewhat inferior position for many moves before equalizing, and only then looking for an advantage.


Is chess.com's tactics trainer any good for actual tactical improvement?

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


In chess.com analysis, why is a rook promotion better than a queen promotion?

There's no reason why the rook promotion is better. Don't listen to engines in positions where there's such a big imbalance


First, I think that your lack of faith in strong computers is misplaced. My Stockfish 11 quickly gets up to a depth of over 40 ply, and still reads 0.00. Just because a position is imbalanced, it does not mean they are wrong. It would be a truly exceptional case at that depth for them to be wrong. That said, regarding your sentence about who has the advantage, it is clear that only black can legitimately try to win this. White should have no prayer of winning this, but nevertheless, as with any position, if you try too hard, you can lose; and I give several lines below where it is possible for black to push too hard, and lose, or at least, be worse. I have pushed like that in similar positions myself, so I can relate.

The evaluation of the position is such:

White has one pawn for the exchange, but has several other pluses. For example, not only does white have the move, in essence, white sometimes might have two moves since black might eventually have deal with the threat of Re8 mate in some lines (right now, Rf8 would work if the Rb8 moves off the back rank). Related to that, the Ng5 is a monster for now, and combines nicely with the Re2, which will be seen in a number of lines below, and white owns the file. Black also has very weak pawns spread out over three pawn islands, which give white a lot of targets to counterattack. Lastly, and we see this in a few lines, if g7 drops, the connected passers on g3 and f4 gain a lot of strength, and provide ample counterplay.

In contrast, black has the exchange, and the possibility of c4 seriously weakening the white queenside. Ideally, black should want to trade a set of rooks since R vs. N endings with pawns on both sides are often among the easiest endings to win.

There are a virtually unlimited number of possibilities here since they all read 0.00, so you can go down any number of paths, but that demonstrates that the computer sees a GREAT NUMBER of defensive resources since white is very active. That is not to say that there is not the opportunity for a lot of play. Equal here does not equal a "dead draw" by any means.

I am going to give the two main plans that I can see for black: Trying to trade a set of rooks, and playing c4.

 [FEN "1r4k1/6p1/2p2r2/p1pp2N1/P4P2/1P1P2P1/2P1R1K1/8 w - - 0 1"]

 1. Kf3 Rff8 (1... c4 2. dxc4 dxc4 3. bxc4 $1 {This look very weakening, but white is active enough to maintain the balance.} Rb4 4. Re8+ Rf8 5. Re7 {Only move.} Rxc4 6. Ne6 Rf6 (6... Rf7 $2 7. Re8+ Kh7 8. Ng5+ Kg6 9. Nxf7 Kxf7 10. Rc8 Rxc2 11. Kg4=) 7. Rxg7+ Kh8 8. Re7 Kg8 (8... Rxc2) 9. Rg7+ Kh8 10. Re7= Rxc2 $2 11. g4 $16) 2. Ne6 Rfe8 3. Nxc5 Rxe2 4. Kxe2 Kf7 5. c3 Ke7 6. Kf3 Rh8 (6... d4 7. cxd4 Kd6 8. f5 Kd5 9. Ke3 Re8+ 10. Ne6 g6 11. g4 gxf5 12. gxf5 Re7 13. Kf4=) 7. Nb7 Kd7 8. d4 Rh2 9. Nc5+ Kd6 10. b4 axb4 11. cxb4 Rb2 12. a5 Rxb4 13. a6 Rb2 14. f5 Kc7 15. Ne6+ Kd6 {Only move.} (15... Kb6 $4 16. Nxg7 Kxa6 17. f6 Rb8 18. Ne6 $18) 16. Nxg7 c5 17. dxc5+ Kxc5 18. g4 Ra2 19. Ne8 Ra3+ (19... Rxa6 $4 20. f6 $18) 20. Kf4 Ra4+ 21. Kg5 (21. Kf3=) 21... Rxa6 22. f6 Ra7 23. Kg6 d4 24. f7 Rxf7 25. Kxf7 d3 26. Nf6 Kd4 27. g5 d2 28. g6 d1=Q 29. g7 Qb3+ 30. Kg6=


Have there been any simul round-robin games?

Although I've never seen such a simul in action, I've heard of a similar concept before. The person who explained it to me called it something like "walking clock simul", but I doubt if there is an official name.
He applied it to a single round-robin (instead of a double round-robin) and a line of boards (instead of a grid), but the idea remains the same.

In any case, for N players, the number of required boards is N*(N-1)/2 for a single round-robin or N*(N-1) for a double round-robin.

For 4 players (A, B, C, D), the pairings of a single round-robin could look like this:

A - B
C - D
D - A
B - C
D - B
A - C

In his format, the players would walk in the same direction (for instance clockwise) around the boards.

By the way, it is also possible to apply the idea to Swiss tournaments. For N players and M rounds, the number of necessary boards is M*N/2. Note that a single round-robin can be seen as a Swiss tournament with M = N-1.


Am I too late to be a professional in chess?

Sorry to put this bluntly, but you have absolutely no chance whatsoever of becoming a professional player if you are rated only 1600 at age 32.  This is not a realistic ambition.  People improving from 1600 to grandmaster level in their 30s and beyond is something that simply never happens.  It's very rare to reach grandmaster level if you are only 1600 at the age of 18, never mind 32.


The first point to note that this kind of draw claim only applies when there are no increments. Since digital clocks are almost universal in advanced and normal chess countries it should (I stress "should") rarely arise.

Note also that FIDE proposes to ban analogue clocks and insist on increments in FIDE rated tournaments from 2021, so then the problem should disappear entirely.

There are three cases which can arise:

1) No increments but one or more digital clocks is/are available. In this case the recommended course is for the arbiter to give both sides a 5 second increment, give the claimant's opponent an extra 2 minutes, offer the claimant's opponent a draw which he can decline or accept in the normal way and the game continues to one of the three normal conclusions of win, draw or loss.

2) The player makes a claim that his opponent is not trying to win the game by normal means but just shuffling the pieces quickly to try and win on time. In this case the arbiter will watch the game and if he judges this is correct he will award the draw. He may do this (award the draw) even after the flag has fallen but the claim cannot be made after the flag has fallen and if it is made with just a few seconds left the arbiter will not be able to come to a conclusion and the game will be lost on time.

3) The player makes a claim that his opponent cannot "win by normal means". This is different from "win by any means". For instance if the player is a queen up and crushing his opponent then his opponent might have enough material to win via helpmate but would almost certainly lose if the claimant had enough time.

Another possibility would be if the game was still in the middlegame when, clearly, anything could still happen. In this case the claim would be rejected immediately, the opponent would be given an extra 2 minutes and offered a draw which he could accept or decline.

These are straightforward cases. More problematic would be where the claimant has a rook against a rook and pawn in a theoretically drawn position. This would be the opposite extreme. In this case the arbiter would ask the players to continue and watch the game again possibly until the flag falls. He would then have to judge whether or not the claimant had displayed the required theoretical knowledge to hold the draw. Clearly if the claim is made with just a few seconds on the clock this is not going to be possible and the game is going to be lost.

This same principle applies to all endgame cases where best play would result in a draw but the opponent can win if the player lacks the required theoretical knowledge, even lone king against king and rook's pawn. It should be a trivial draw but the claimant must demonstrate during his time remaining that he has that theoretical knowledge.

Once your flag has fallen no claim can be made even if it is mate in 2.


How is notation done for similar pieces capturing the same piece?

Your two knights are on d2 and f2.

Ndxe4, Nfxe4,

Your two knights are on f2 and f6.

N2xe4, N6xe4

Your three knights are on d2, f2 and f6 (you promoted a pawn)

Ndxe4, Nf2xe4, N6xe4


I don't know the game you have in mind, but the following is one example of such a drawn position in this ending (as can be verified with a tablebase query):

[fen "8/8/1r4kP/6P1/2R2K2/8/8/8 w - - 0 1"]

White has no winning way to break the blockade and make progress. If the blockade is one rank further up the board, though, it can be broken straightforwardly:

[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[FEN "8/1r4kP/6P1/2R2K2/8/8/8/8 w - - 0 1"]

1.Kg5 Ra7 2.Rf5 Rb7 3.Rf7+ Rxf7 4.gxf7 *


If you go to this site:
https://ccrl.chessdom.com/ccrl/4040/games.html
You should be able to download pgns of games by month, or games played by any specific engine of your choosing.
Also on the home page:
https://ccrl.chessdom.com/ccrl/4040/
You can search around and find stats of how certain engines score against each other.


This looks like a 'no engines' question, otherwise ALNS would have just used Stockfish. Be afraid, B-player analysis is happening!

[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

1...Rxe3 2.Kxe3 Re8+ 3.Kd2 Bf4

[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

1...Rxe3 2.Kxe3 Re8+ 3.Ne4 Rxe4+ 4.dxe4 Qxe4+ 5.Kd2 Bf4+ 6.Kc3 Nd5+ 7.Kb3 Qb4#

[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

1... Rxe3 2.Kxe3 Re8+ 3.Ne4 Rxe4+ 4.Kd2 Bf4+ 5.Kc3 Nd5+ 6.Kb3 Qxf2 7.dxe4 Qb6+ 8.Kc4 Ne3+

[Title "White survives, sort of"]
[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

1... Rxe3 2.Kxe3 Re8+ 3.Ne4 Rxe4+ 4.Kd2 Bf4+ 5.Kc3 Nd5+ 6.Kb3 Qxf2 7.a3 Qb6+ 8.Ka2 Be5 9.c3 Nxc3+ 10.bxc3 Bxc3 11.Rg2 Qe6+ 12.Qb3 Re2+ 13.Rxe2 Qxe2+ 14.Kb1 Qxd3+ {After this Black is able to trade the pieces and have a deadly pawn majority on both sides of the board, and an extra piece. Further play was very computery so I didn't post it.}

[Title "Stockfish calls it a win"]
[FEN "2krr3/ppp2ppp/3b1n2/8/6P1/2NPB3/PPP1KPq1/R2Q2R1 b - - 0 1"]

 1... Rxe3+ 2.Kxe3 Re8+ 3.Ne4 Rxe4+ 4.Kd2 Nd5 {Here's the killer. The knight closes the luft on c3} 5.dxe4 Qxf2+ 6.Qe2 (6.Kc1 Bf4+ 7.Kb1 Nc3+ 8.bxc3 Qb6#) Bf4+ {Now Black strips the Queen's defender} 7.Kd1 Ne3+ 8.Kd2 Nxg4+ 9.Kc3 Qxe2 10.Rge1 Bd2+ 11.Kd4 Qf2+ 12.Kd5 c6+ 13.Kc4 Ne5+ 14.Kb3 Qb6+ 15.Ka3 Qb4#


Why do many team championships have only 4 boards?

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

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

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

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

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

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


Should any information written on the scoresheet by the players be accurate?

I believe this rule has been used before, against Wesley So in the 2014 ACP Golden Classic tournament (more here)

Both you and "LuisFSiles" in the chess.com article you quote are wrong. So was warned three times not to write other things on his scoresheet but was not punished (in that case by losing the game by default) for writing unauthorized material on his scoresheet. He was punished for deliberately disobeying the arbiter on three occasions.

Isn't this a violation of the rules?

Yes, it is, albeit a very minor one. The normal approved arbiter action would be to warn the player not to do it again.

Why didn't the arbiters take appropriate action?

Your assumption doesn't make sense. We don't know if the arbiter took action or not.
If the arbiter saw (and paid attention to) the fact that Carlsen had written what he did on his scoresheet then the appropriate action for the arbiter to take would have been to do what the arbiter in the Wesley So case did and give Carlsen a warning. We don't know if that happened or not. In any case. not surprisingly, there was no repeat offence from Carlsen. Carlsen did not wilfully disobey the arbiter even once let alone three times. Hence no reason why the arbiter would take any more obvious action that we would know about like awarding a time penalty.
In this kind of high level tournament the PGNs of the games have to be sent to FIDE. If there are no DGT boards then this transcribing to PGN has to be done by a human but that would not necessarily be the arbiter and it would not necessarily happen the same day. It might even happen after the tournament. In this case I would expect that Carlsen would be playing on a DGT board and so the moves would be recorded electronically. In that case an arbiter might never check the scoresheet and would never know.
What has also to be remembered about the Wesley So case is that it was instigated by an opponent complaining to the arbiter.


GUI for stockfish that can analyse the full game

Yes, this is possible. But in a slightly crude way. It is possible with Arena Chess GUI 3.5. What you need to do is the following-

1) Open the pgn file in Arena GUI

2) Confiure any engine with Multi-PV enabled to your choice of top "N" moves.

3) Now open Engines > Automatic Analysis

4) In Source tab select "List of EPD/PGN Files" and Click the icon for adding all PGN files for which you need the automatic analysis.

5) Check "WhiteMoves" and "BlackMoves"

6) If the PGN file contains multiple PGNs then select the range of game numbers you want it to process

7) Select range of move numbers if needed

8) Now go to the Output tab and select "Write in protocol file"

9) Now start the analysis and after its done, you can check the protocol file. The last section for each move contains the best "n" moves calculated by the engine. Parsing this protocol file should be really easy if you want to automate it.

Note: The pgn itself can be altered to add the scores, but it does not add multiple moves at one shot.

Example output in the protocol file:

   ---------------------------------------------------------------------------
16/25   00:01      3,444,292    2,274,961   -0.04   0-0 Ne5 Nc6 Nd2 Rd8 Qb3 Bd7 0-0 Qc7 Re1 h6 Ndf3 Ne4 Nxd7 Rxd7 Ne5 Bxe5 fxe5 Qb6
16/25   00:01      3,444,292    2,274,961   -0.08   Nc6 Ne5 Bd7 Nd2 0-0 Qb3 Qc7 0-0 Rfc8 Re1 h6 Ndf3 a6 Bd3 Na5 Qc2 Nc4 Bxc4 dxc4
16/25   00:01      3,444,292    2,274,961   -0.08   Bd7 Qb3 Qc7 Ne5 Nc6 Nd2 a6 0-0 0-0 Re1 Rfc8 Bd3 h6 Ndf3 Na5 Qc2 Nc4 Bxc4 dxc4
8/16/2014 12:24:59 PM, Time for this analysis: 00:00:02, Rated time: 00:04

Of course it also has flexibility to tailor what gets dumped into the file as well.


Just develop your pieces. 5.Nf3 makes sense, preparing to castle. 5.Nxc3 is also reasonable; if Black refuses to play ... cxb2, you'll probably have to play Nxc3 at some point anyway. These are the only two regularly played moves in the given position.


Reference request: Books/Video series on prophylaxis

There are YouTube videos covering these specific areas but I'm not convinced I could recommend them. Nevertheless, here are 3 for you to try and make your own mind up. They are at least free.
Mastering the Middlegame with Atul Dahale : Aaron Nimzowitsch : Prophylaxis! (link at about 15 minutes in because before that it is mostly irrelevant drivel)
Tigran Petrosian - World Chess Champion - Master of Prophylaxis - Kingscrusher Radio Show (not one of Kingcrusher's best IMHO)
Karpov's Prophylaxis with Karpov's Prophylaxis with IM Valeri Lilov (IM Valeri Lilov, who he?)
There are far better books if you are prepared to accept some fine games collections of these players.
Nimzowitsch:
Everybody is familiar with "My System" but "My Praxis" is probably better for stronger players. It is a collection of annotated games by Nimzowitsch with the intention of demonstrating "My System" in practice, kind of like the name suggests.
Petrosian:
Old school, perhaps, but I like PH Clarke's "Petrosian's Best Games of Chess 1946-63"
More modern (and with much deeper annotation) is Kasparov's "My Great Predecessors Part 3 Petrosian Spassky" roughly half of which is devoted to Petrosian and which includes a specific chapter on Petrosian's prophylaxis - "Miracles of Prophylaxis"
For Karpov there is more choice:
For a simple game collection there is PR Markland's "The Best of Karpov" but for in-depth quality annotations you can't beat the three books Kasparov wrote of the annotated games he played against Karpov:
Kasparov vs Karpov 1975 - 1985
Kasparov vs Karpov 1986 - 1987
Kasparov vs Karpov 1988 - 2009


What is the theoretical maximal material difference of a dead draw which is not a stalemate?

[fen ""]

1. a4 b5 2. b4 bxa4 3. c4 c5 4. d4 cxb4 5. e4 d5 6. f4 dxc4 7. g4 e5
8. h4 exd4 9. Ba3 g5 10. Nc3 gxh4 11. Qb3 f5 12. Kf2 h3 13. Kg3 h2
14. Bd3 Qa5 15. Kh4 dxc3 16. Kg5 h5 17. Kg6 cxb3 18. g5 Rh7 19. Ra2 Rc7
20. Bc4 Rxc4 21. Kh7 Bd6 22. g6 fxe4 23. Kg7 hxg1=Q 24. Kh7 h4 25. Kg7 h3
26. Kh7 h2
27. Kg7 bxa3 28. Kh7 bxa2 29. Kg7 Qgb6 30. Rg1 hxg1=Q 31. Kh7 Nc6
32. Kg7 Nd8 33. Kh7 Nf6+ 34. Kg7 Nd7 35. Kh7 a1=Q 36. Kg7 c2+ 37. Kh7 Qab1
38. Kg7 Qb8 39. Kh7 Q1b7 40. Kg7 c1=Q 41. Kh7 a2 42. Kg7 a1=Q+
43. Kh7 Qab1 44. Kg7 Qb1b6 45. Kh7 a3 46. Kg7 a2 47. Kh7 a1=Q 48. Kg8 Qab1
49. Kg7 Q1b5 50. Kh7 Nf6+ 51. Kh8 Bd7 52. Kg7 Nc6 53. Kh8 Be7 54. Kg7 Bd8
55. Kh8 e3 56. g7 Ne4 57. Kh7 Qab4 58. Kh8 a5 59. Kh7 a4 60. Kh8 a3
61. Kh7 a2 62. Kh8 Qxf4 63. Kh7 a1=Q 64. Kg8 e2 65. Kh8 Nc5 66. Kh7 Re4
67. Kh8 Re6 68. Kh7 Qf4b8 69. Kh8 Ra6 70. Kh7 Qb6a7 71. Kh8 Nd4
72. Kh7 Rad6 73. Kh8 e1=Q 74. Kh7 Qg1e3

White can force a draw from this position with 75. g8=Q+ and perpetually check the black king.  The end position given above (before the pawn promotes) is the moment of maximum material difference in this forced draw.


Giuoco Piano / Two Knights Defense / Fried Liver Attack

Most people agree that the Fried Liver attack is better for white. So black's 5...Nxd5 is inferior to the less scary 5... Na5. Assuming that black goes in for the Fried liver though, white can play either 6. Nxf7 or 6. d4. Both lead to similar attacks.

In the Nxd5 Nxf7 line, however, black's moves are forced until move 8, where black has the choice to defend the pinned knight with Ne7 or Nb4. Any other moves just admit defeat and give back the piece to white for a completely misplaced king and underdeveloped position.

Most pros play 9. 0-0 or 9. a3. Interestingly, Qe4 is recommended by my engine... but the a3 lines are so good for white, that I don't really see any reason to deviate. Personally, I've only played a3 with good success.


Are there any lines in the Lopez Opening / MacLeod Attack that are actually good for White?

The reason to play 1.e4 e5 2.c3 is probably to go for a slow manoeuvring/strategic game without much theory.

After the natural 2...d5, white can go for 3.d3 and in case of 3... dxe4 4.dxe4 Qxd1 5.Kxd1. This transposes into a familiar position with one tempo up and reversed colors compared with 1.e4 d6 2.d4 d5 3.dxe5 dxe5 4.Qxd8 Kxd8.

Note that in the line 1.e4 e5 2.c3 d5 3.d3 dxe4 4.dxe4 Qxd1 5.Kxd1 the move c3 is useful because it gives the King the square c2 to hide and a good control on d4.


Would it be a decisive advantage, if the opponent would not be allowed to castle?

In fact, Larry Kaufman (Komodo) did computer testing on this with Komodo, and found that White has about 50% winning chances when Black starts with no castling privileges. So it's a toss-up.

http://talkchess.com/forum/viewtopic.php?p=650339#650339

  Here is a perfect example: In the initial position, forbid Black from
  castling. Komodo gives that position a score that is around where I
  think the dividing line between win and draw lies. I had Komodo 9.3
  play it out on four threads (to insure variety due to MP
  unpredictability) a hundred times at game in one minute. getting 49
  White wins, 46 draws, 5 Black wins. Then at two minutes plus one
  second, a similar result: 49 White wins, 49 draws, 2 Black wins. So
  just forbidding castling for Black appears to put the game right on
  the win/draw line. Of course results could be different at TCEC time
  controls on many cores, but it's not obvious whether the White win
  percentage would go up or down.

There have been some who have dubbed this "Kaufman chess", and suggested it as a sort of long-time control Armageddon method (rather than two rapid games, then two faster games, then two blitz games, and finally a blitz Armageddon, as in the FIDE World Cup).


I don't know about Zillions specifically, but it's a reasonably good strategy in most games to maximise your own flexibility of action while minimising your opponent's.  This is certainly true for chess; there are competent chess engines (ie. strong enough to beat an amateur consistently) which use only material value and mobility for evaluation.

The Beale Effect (ie. minimax with random position evaluations) yields a reasonably good chess engine with a modest depth of search, plateauing around 2000 ELO.  This relies entirely on a second-order effect of mobility, ie. you're most likely to find the highest random value in a part of the game tree that branches a lot.

I would not be surprised, therefore, to find that Zillions uses either a random evaluation or one based on mobility.  The value of a piece, after all, is strongly correlated with its mobility.


The St. Louis Chess Club has a YouTube page full of video lectures, many of which delve into the opening ideas.  iChess.net also has such videos, for example: "The Ideas Behind the Chess Openings! IM Vlaeri Lilov (Webinar Replay)"

Then there are some wiki pages that actually have decent explanation of some openings.


A light-squared bishop move here is in order so that white can castle soon. The choices that you mentioned are definitely the only ones that aren't dumb/lose a tempo.

Be2 is probably the worst of the reasonable choices. Its only result is to allow castling, and it kind of clogs up white's middle - potential moves like Ne2 or Qe2, which may show up at some point, are off the plate.

Bc4 and Bd3 are both solid, I think. There likely wasn't much of a difference in the engine evaluation for these moves, and depending on the tools you used to conduct this analysis, the difference may be within the margin of error for the program. Essentially, I'm not sure there is a measurable difference between these moves in terms of evaluation.

Assuming that there is an actual difference, you might also consider that engines are fairly notorious for NOT playing attacking chess. It has been argued that they focus too much on material imbalances and not enough on position/pressure/psychology. The move Bc4 "feels" scary, but the engine sees that with perfect play, it isn't much of a threat. The pressure on the e4 pawn, however, will be real with perfect play, and it moves to defend that pawn.

Essentially, Bc4 might be more practical in a game between imperfect people, but the attack it provides is not real enough to matter in a perfect game - thus Bd3 is technicallybetter.

Play whatever you're more comfortable with.


After 1.e4 e5 2.Nf3, is 2...Nf6 safer and easier to learn than Nc6?

As an amateur player, you should know the connotation that 2...Nf6  (The Petrov defense) has a reputation of being more boring and more of a draw than 2...Nc6 (leading to the Ruy Lopez, Italian, and Scotch games). However, this really doesn't apply at the amateur level. In fact, you're much more likely to win or lose than draw, unlikely to the masters' database showing that certain lines have a drawish tendency.
So my suggestion, as unexciting as it is, is play what you like! Try out Nf6, try out Nc6, and see what pawn structures/middlegames you're getting in your games. Do you like them? Do you prefer one or the other? Play that one more often!


How to view contents of database in ChessBase

Ok, I'll handhold you, but I have CB 13. I doubt it is much different.

When the program loads, you get a tree at the left side. Select Database Path/Bases. this should load a file list of the databases you have. Find the one with the largest number of "Games". For me, it is Big database 2002, but I think I loaded that from a previous version. Otherwise, you can click the "Board" icon at the top and open a new board. At the top of the Board is an icon labeled "Online". That will open a subwindow of games from the online database.

If that does not help, hit the help files.

You can also go to This Week In Chess and get weekly games from most major tournaments without annotations. I do this every month or so. It is roughly 4000 games a week.

Good luck. Help files are your friends.

~Professional Software Engineer


Is it true that a good "flanker" (flanking position) is worth more than a pawn? If so, why?

I will give you my view, though I'm only a FIDE 2200 player. Such rules do not apply in all games and you usually should not let them affect the game. That does not mean that all rules you hear are not valid, for example take the first example: a sacrifice of a piece for two pawns and attack on the king is usually good compensation. But it always depends on the position, it is up to the player to determine the strength of the attack. I would go with the known rules using them carefully. All rules have exceptions.

Compensation in the Nimzowitch game is perhaps the hardest to explain, I would guess that he saw the end position before the sacrifice since he was great tactical player.

In the Capablanca game the compensation is more clear, a bishop, a protected passed a-pawn and white square dominance and it is true that black is so badly coordinated that he cannot effectively use his kingside flank.

To the original question, it is always some advantage that compensates for a pawn and yes, it could be control on some part or side of the board. It is always up to you to determine the extent of the advantage. Your observation no.3, though: there are openings where black is confined to little space but gains a flexible position so space advantage alone is usually not compensation in itself.


Is it valid according the FIDE chess rule?

The king does not cross b1 (only the rook does). It also does not end up standing on b1 following the castling. Hence, the quoted rule is not violated.


Did Stockfish have access to an opening book in its games against AlphaZero?

Both Nakamura and the StackExchange answer were correct - Stockfish didn't use an opening book. I think Google did that to make a fair comparison as AlphaZero wasn't using an opening book as well.
EDIT
I didn't see anything about opening book for Stockfish in the paper. I'm not the only one.

http://talkchess.com/forum/viewtopic.php?t=65910&postdays=0&postorder=asc&highlight=stockfish+book&topic_view=flat&start=10
As far as I read the paper, I didn't see a book for Stockfish mentioned, so I guess, match was bookless.

and

http://talkchess.com/forum/viewtopic.php?t=65909&highlight=stockfish+book
While this is indeed incredible, show me how it beats SF dev with good book and syzygy on equal hardware in a 1000 game match.


Does anyone know if there is an English translation of this book?

It is hard to prove that something does not exist, but I read and speak Russian, and I just looked at that book in Russian. It deals a lot with tabias of various openings, and resulting middlegames.

The only book of his in English I could find is "Chess : Knowledge, Training, Mastery", and that is definitely a different book, as I also have that in Russian: "Шахматы - Наука, Опыт, Мастерство (1990)" (strictly translated as "Chess: Science, Experience, Mastery").

Lastly, I found a site that seemed to say that it was only available in Russian, which I tend to agree with after researching it. Interestingly, he has a two-volume series in Spanish though, and one more in Spanish.


Chess challenge #10: A beautiful knightmare

My semi-educated guess at a solution:

   1.Nf6 Kg7 2.Nh5 Kg6 3.Bc2+ Kxh5 4.d8Q Nf7 5.Ke6 Nxd8 6.Kf5 e2 7.Be4 e1N 8.Bd5 c2 9.Bc4 c1N 10.Bb5 Nc7 11.Ba4 and Bd1 should lead to mate. It's all pretty forcing, at the beginning black has to avoid blockading f7 or stepping into d8Q+ and then the bishop starts threatening mate all over the place until black runs out of knights ...


Is a timed game less strategic than a non-timed game?

As far as I know, clock was introduced to combat abuse regarding time. So it's a needed thing. You say you don't like to play with a clock. And you immediately add about blitz. So it isn't clock that's the problem. It is that certain limited amount of time that makes you uncomfortable. To deal with this, I suggest you to just play longer games (though, with clock). I believe I understand your problem, since in some situations I feel exactly your pain: I am a slow thinker and I feel extremely stressed when I try to play chess with 10 minutes per game, but it becomes OK as soon as I get at least 15 minutes per game.

While clock is a stress factor, as you correctly point out, it also has positive consequences. One of them is that when you think about a move - you "float" less between estimating the same variant over and over, thus wasting time. You learn to be disciplined and estimate each variant only once (and have a final look over the one you choose just before making the move on board).


Where can I download gaviota endgame tables?

https://chess.cygnitec.com/tablebases/gaviota/

Use wget recursively: https://serverfault.com/questions/25199/using-wget-to-recursively-download-whole-ftp-directories for all the files.


I am a not missing anything and it is indeed not possible, confirmed by the app programmer, which pointed to me the repository of its app :

https://github.com/gkalab/scidonthego

and saying that he won't provide any support/modifications except bug correction for scid on the go in the future. He is by the way happy to receive pull requests from other contributors, I will give it a try if I can spare time.


Engine is evaluating the same position at the same depth with different score

What you are seeing does not necessarily indicate a bug.
You are searching the position with two different bounds.  Your engine is fail-hard (because you return beta and not eval in the case of a fail-high), so the score that comes back from eval is going to be constrained within the bounds you provide.
In the second case (using the numbers from your diagram, not your code) you are searching with a bounds of [-20, -5] and your score is -5.  This is fine.
In the first case you are searching with a bounds of [-20, -15] and your score is -15.  This is also fine.  It would be impossible for this search to return a value of -5 because it is outside the bounds you provided.
In either case, what the search is telling you is that this position is better (relative to the side to move) than the bounds you provided because in both cases the search is failing high.


How should black develop the dark squared bishop in the advance variation of the French Defense?

The starting position is

[FEN ""]
1. e4 e6 2. d4 d5 3. e5

White has committed with e4-e5 since the e4-d5 tension is lost. In return, white controls the vital squares d6 and f6 for a future attack as well as stopping black from developing normally. The e5 pawn has its pawn base on d4. The critical line for black in this variation is to build up a pressure against the d4-square. The f7-f6 break will also come into consideration. The variation can go like this

[FEN ""]
1. e4 e6 2. d4 d5 3. e5 c5 4.c3 Nc6 5.Nf3 Qb6 6.a3 a5

Black decides to wait with the Bf8 and focus on building a pressure on d4. After a future f7-f6, the Bf8 can choose between Bf8-e7 and Bf8-d6. In general, the Bf8 already has an important role, because it controls the f8-a3 diagonal and is ready to recapture with Bf8xc5. So there is no need for it to move at all until the situation in the center is more clear.


What is the worst opening move in Chess960 for White?

This calls for some scripting, so here's my first hasty attempt at it ;)

Here's a quick way you can do the search on your own in python, using stockfish 10 and only the python-chess package. All open-source and free-software!

Briefly, what the script will do:

Consider all 960 positions, one at a time
For each position, it scans over all legal white moves
For each move, it evaluates the position with a engine ponder time given by user (e.g. 1 second)
If the evaluation is below the given threshold (e.g. -2.0) then it shows the board, the FEN, the move and the evaluation.
At the end everything will be saved in a text file, so you don't need to log the printouts in the terminal.

Examples found running the script for first 5 chess960 positions

Let's showcase it for the first 5 chess960 positions where:

The evaluation threshold is set to -1.0
The ponder time is 1.0 second per move.

Here are the found cases: (below is the saved results in a textfile, first column is the chess960 position FEN, 2nd column the move whose evaluation fell below the threshold, and the 3rd column is the corresponding evaluation)

bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w KQkq - 0 1    g4  -2.19
bqnbnrkr/pppppppp/8/8/8/8/PPPPPPPP/BQNBNRKR w KQkq - 0 1    g4  -1.51
bqnnrbkr/pppppppp/8/8/8/8/PPPPPPPP/BQNNRBKR w KQkq - 0 1    g4  -1.66
qbbnnrkr/pppppppp/8/8/8/8/PPPPPPPP/QBBNNRKR w KQkq - 0 1    g4  -1.35

1.g4 seems to be commonly the worst move among the first 5 setups.

Not so surprising, since in all the so far considered chess960 positions, namely the first 5, the king stands on the usual kingside (specifically, on g1).

Thus, 1.g4 is a highly weakening move with the king on g1.

Here are the positions (updated, 3 more examples found by running script longer):

 eval = -2.19

 eval = -1.51

 eval = -1.66

 eval = -1.35

 eval = -2.8

 eval = -2.07

 eval = -2.12

Continue the search on your own using the script

To go over all 960 positions takes a lot of time and computational resources. So I leave it up to you and other if they are interested, to run the script for longer ponder times, to scan all 960 positions, and to play with the evaluation threshold of interest. To do that on your own, here's the python script, using Python 3.7.4, python-chess 0.30.1, and Stockfish 10 (place the engine file in same folder as the script):

import chess
import chess.engine
import os
import sys

arguments = sys.argv
pondertime = float(arguments[1])
evalthreshold = float(arguments[2])
#here we assume the engine file is in same folder as our python script
path = os.getcwd()
#Now make sure you give the correct location for your stockfish engine file
#...in the line that follows by correctly defining path
engine = chess.engine.SimpleEngine.popen_uci(path+'/'+'stockfish-10-64')

lsfens = []
lsmoves = []
lsevals = []

numberofpos = 960

for i in range(numberofpos):
    board = chess.Board.from_chess960_pos(i)
    print('Currently analysing the position below')
    print(board)
    print('--------')
    for el in board.legal_moves:
        info = engine.analyse(board, chess.engine.Limit(time=pondertime), root_moves=[el])
        t = str(info["score"])
        if t.startswith('#'):
                print(str(board.san(el))," eval = mate in ", t)
        else:
            if round(int(t)/100.,2)<evalthreshold:
                print('Starting 960 position index: ', board.chess960_pos())
                print('Position FEN: ',board.fen())
                print(str(board.san(el))," eval = ", round(int(t)/100.,2))
                lsfens.append(board.fen())
                lsmoves.append(str(board.san(el)))
                lsevals.append(str(round(int(t)/100.,2)))
    print('--------------------------------------')

engine.quit()

with open('FoundPositions_Pondertime_'+str(pondertime)+'_threshold_'+str(evalthreshold)+'.txt', 'w') as file:
    for i in range(len(lsfens)):
        file.write(lsfens[i]+'\t'+lsmoves[i]+'\t'+lsevals[i]+'\n')

How to run the script:

Copy paste the code into a textfile and save it with a name like 960evaluator.py
Make sure you have python3 installed, similarly for python-chess module (see here for installation) and have downloaded the stockfish binary for your OS.
Place the engine file and the script in the same folder, and open a terminal in that folder
Run the script with the command python 960evaluator.py 1.0 -2.0
Note the first argument you give after the script name is the ponder time per move in seconds. The higher the ponder time value, the more accurate the evaluation.
The second argument is the evaluation threshold: that is, all positions with 1st move evaluations below the given value (in this example -2.0) will be printed in terminal and saved at the end (you could do the saving while running so you can crash the script without losing the so far found cases).
Again, the found cases will be printed in terminal as they are found, but also saved in a text file placed in same folder as your script.

The terminal printouts will look like:

Currently analysing the position below
b b q n n r k r
p p p p p p p p
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
P P P P P P P P
B B Q N N R K R
--------
Starting 960 position index:  0
Position FEN:  bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w KQkq - 0 1
g4  eval =  -2.19

Have fun scanning, though do so with caution: running chess engines for long times on personal machines is bit risky as it quickly heats up!


What does Kasparov mean by "I was behind in three and even in one after six games"?

He is talking about the score after the sixth game of each of his matches with Karpov. To be precise, these were the scores after game six (shown as Kasparov-Karpov, not counting draws, to follow the same convention as the quote from the book):

1984: 0-2
1985: 1-2
1986: 1-1
1987: 1-2
1990: 1-0

As you can see, Kasparov was behind after the sixth game in three matches: 1984, 1985, and 1987. The score was even in one: 1986. Put both facts together and you have "behind in three and even in one". And indeed in only one match, 1990, Kasparov was ahead after the sixth game.


I'm a chess player and programmer. There was actually a paper on this 10 years ago about the timestamp and other security on ICC. You should read it with the understanding that things may be different now:

How to Cheat at Chess:
A Security Analysis of the Internet Chess Club

But in general, you are correct. It is possible to manipulate the times reported in timeseal (timestamp). I've actually done it, even with ICC's official interface, just to see if it can be done. Speed hacks exist for many games and I used an existing speed hack program to slow down my clock instead of speeding it up (which you normally would do to run faster in a game). The result was a game I played vs KBNK (a bot which lets you practice B+N mate), in which I mated the computer after about 30 moves in less than 3 seconds played time. Averaging 0.1 seconds per move or so on a non-trivial mate is definitely unnatural.

I reported the effect to the administrators of the site, but I was told they were able to detect it. In fact, they had a log of my fraudulent time stamps detected (somewhere... I assume they can see blatant false reports, as well as compare it to TCP/IP timestamps and see if the numbers are reasonable). I was told that they were able to detect such cheating and to please not use it but thanks for my concern.

So, yes it is possible to manipulate anything client side, but it is also possible that they can detect fraudulent time stamps server side. Better chess servers typically already have a team of people that investigate reports of cheating, either by computer or clock manipulation.


How the engine can detect the 3-fold repetition using FEN input?

https://en.wikipedia.org/wiki/Forsyth%E2%80%93Edwards_Notation

"FEN does not represent sufficient information to decide whether a draw by threefold repetition may be legally claimed or a draw offer may be accepted; for that, a different format such as Extended Position Description is needed."

QED.


Are there moves in chess that are considered unsporting?

What is "unsporting"? To my mind (backed up by the two or three definitions I quickly browsed), it's mostly about behaviour. To act sportingly is to be fair and respectful, to play for the (mutual) enjoyment of the sport, and—here's the tricky part—to not abuse the rules for an unfair advantage.

Unsporting behaviour in general, and the last kind in particular, often leads to new rules being introduced. ("No underarm bowling in one-day cricket" is the first example that comes to mind.)

I can't think of anything on the board (as opposed to players' behaviour, or abusing the clock) that would strike me as unsporting. And the lack of new rules to counter anything on the board would seem to support that view.

So essentially, no: in standard chess, "if it's legal, then it's good". People might complain about how some style of play (whatever's new and trendy and effective) is changing the spirit of the game or whatever, but so far everything still seems to be fair play.


This depends on a lot of things, but most importantly: your playing level and the topic.

For example, if it is an opening book, it heavily depends on the opening. Some opening variations which are main stream today, didn't even exist in the seventies, or were rarely used (like the Berlin Wall in Ruy Lopez). Others haven't seen that much development (QGD, and offbeat openings like the King's Gambit).

Middlegame & strategy books usually last longer; Nimzowitsch' Mein System is 90 years old but still a useful read.
The same is true for endgame books, with one notable exception (which doesn't appear that often in practice): endgame tablebases have completely changed the view on certain endgames like K+Q vs. K+B+B (thought to be a draw, now known to be a win for the Q) and K+Q vs. K+N+N (the other way around).

If you are a <2200 player (like me), you shouldn't worry too much about computer evaluations. Though it is a very good practice to analyse the lines given by the books, so kudos for that.


Here's how color-coded analysis looks on the lichess desktop site.

As you can see, depending on the severity of the error (according to Stockfish), different colored bars pop up on the game analysis - blue for an inaccuracy, orange for a mistake, and red for a blunder. A black bar will show if a player loses a forced checkmate sequence or blunders into a forced checkmate sequence. I don't have the app, currently, but I believe that the same thing shows up there, since I used to play exclusively on the app.

You get this color-coded analysis by clicking "request a computer analysis" - it's on the bottom of the screen on PC.

If anyone has the app downloaded at the moment, feel free to screenshot this feature and add it to this answer.


With the rook on e6, Bb6 is mate in two. For instance

Bb6 d2 2. Qb3 mate
or 1. ... N any 2. Qc5 mate
or 1. ... Kc3 2. Qc1
or 1. ... Kc5 2. Qxd3
or 1. ... Ke4 2. Qxe4


Is there a comprehensive coverage for Lasker variation of the Scandinavian defense?

I don't think there is a coverage for this line, but if you don't mind, I have been playing this line for years, so here's my thought.

In this position, black generally takes on f3. The reason is that the move Bg4 per se is aiming to trade off the knight at f3, if not, black will have no reason to play this move among others.

What if black doesn't exchange

a) Bh4 in this position is okay, but white can expand on the king side with h3 and g4. Black cannot really exploit the weakness white created in kingside, as Black piece placement commands black play on queenside.Furthermore, the knight on f3 usually will become a strong piece occupying the outpost e5 in the game later on, while black's light squared bishop is a bad bishop due to blacks pawn structure. This all gives white huge initiative in kingside. For instance

[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Nf3 Bg4 6.h3 Bh5 7.g4 Bg6 8.Ne5 e6 9.Bg2 c6 10.h4 Be4 11.Bxe4 Nxe4 12.Qf3 Nd6

b) Bf4 or any retreating move is dubious, if black plays this, black may as well just play 5. Bf4 at first instead of wasting a tempo, as black has given white a tempo and white can follow up with g4 Ne5 etc. For instance

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Nf3 Bg4 6.h3 Bf5 7.g4 Be4 8.Bd2 Bxf3 9.Qxf3

What to do after exchange

a) What usually goes is like this

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Nf3 Bg4 6.h3 Bxf3 7.Qxf3 c6 8.Bd2 Nbd7 9.Bc4 e6 10.O-O Be7 11.Rfe1 O-O

Black ends up with a solid position

b) Black can also try undermine white's d-pawn if white is careless, due to the lack of f3 knight

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Nf3 Bg4 6.h3 Bxf3 7.Qxf3 c6 8.Bd2 Nbd7 9.O-O-O O-O-O 10.Bc4 e6 11.Ne4 Qa4 12.Bb3 Qxd4 13.Nxf6 Qxf6

c) In some line, black can also play a Bronstein-Larsen-like game.

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Nf3 Bg4 6.h3 Bxf3 7.Qxf3 c6 8.Bd2 Nbd7 9.Bc4 e6 10.Ne4 Qb6 11.Nxf6+ gxf6

Conclusion

If you opt to play Bg4, then you should Bxf3, Bh5 is also playable. Ultimately, the position is something like Caro-Kann for black. Usually, black is behind in development in most lines due to the capture on f3, but the solid position of black compensates it.


Did Stockfish blunder a drawn position against Leela here?

Welcome!
I am not 100% sure of what your are asking.
Are you saying that Stockfish missed a draw by playing Bf8 as shown in the diagram ie there was some other move that could have drawn?
Or are you saying Stockfish missed a drawing line later.
Or are you asking in general where Stockfish went wrong in the game?
If you look at the evaluations then Stockfish seemed to assess itself as losing many moves earlier.
Leela on the other hand thought her position better for quite some time but not necessarily a forced win.
In the lead up to your diagrammed position Stockfish I think is lost and has been for quite a long while.
The Black pawns are wide apart making the defensive Bishop's task very hard. The White K has to keep an eye on one of the pawns whilst the White Rook keeps an eye on the other pawn whilst at the same time trying to harrass and keep out the Black K with checks.
Black has to manoevre carefully but will always be able to shepherd the c Pawn down to the queening square.
I think Stockfish made a strategic error with 40. Ng2 allowing Leela to swap her bad Bishop and get a position with the "Petrosian Knight" verses Stockfish's bad Bishop.
After this swap Leela's Q invaded, Stockfish's position deteriorated leaving a difficult defensive task.
Apologies if I have missed your point.


How to respond to the Taimanov attack in the Benoni?

8...Nfd7 is the most popular line among Grandmasters.

Bareev vs Topalov 2002, 0-1

Bostari vs Polgar 2011 0-1

8...Nbd7 is extremely risky and requires thorough preparation. White does seem to get at least a minimal endgame advantage in the 8...Nbd7 line with best play by Black. Since the advent of strong engines, Grandmasters have avoided it and I would recommend avoiding it as well.

8...Bd7 is just bad and White easily gets an advantage.

I provide some sample lines -

     [Event "8...Nfd7 is Black's best move"]
     [Date "2014.10.26"]
     [FEN ""]

     1. d4 Nf6 2. c4 e6 3. Nc3 c5 4. d5 exd5 5. cxd5 d6 6. e4 g6 7. f4 Bg7 8. Bb5+
     Nfd7 (8... Nbd7 9. e5 dxe5 10. fxe5 Nh5 11. e6 Qh4+ 12. g3! (12. Kd2?! fxe6 13.
     dxe6 O-O 14. exd7 Bxd7 15. Bxd7 Rf2+ 16. Nge2 Rd8=) 12... Nxg3 13. hxg3 Qxh1 14.
     Be3 Bxc3+ (14... O-O 15. exd7 Bxd7 16. Bxd7 Rfe8 17. Bxe8 Rxe8 18. Qe2 Bh6 19.
     Kf1 Bxe3 20. Qg2) (14... Qg2 15. exd7+ Bxd7 16. Bxd7+ Kxd7 17. Qg4+ Kd8 18.
     O-O-O) 15. bxc3 a6 16. exd7+ Bxd7 17. Bxd7+ Kxd7 18. Qg4+ f5 19. Qf3 Qxf3 20.
     Nxf3) (8... Bd7? 9. e5 dxe5 (9... Qe7 10. Qe2 dxe5 (10... Nh5 11. g4) 11. d6)
     10. fxe5 Nh5 11. Nf3 O-O 12. Bxd7 Nxd7 13. g4) 9. a4 O-O (9... Qh4+!? 10. g3 Qe7
     11. Nf3 O-O 12. O-O Na6 13. Re1 Nb4) 10. Nf3 Na6 11. O-O Nb4 12. Re1 a6 13. Bf1
     Re8


Why is this "slow move" with the king a good move?

Just because Stockfish thinks a move is best doesn't mean it is best. But let's see why Stockfish might like it.
When I look at Stockfish's static evaluation of that position, and move the king from  c1 to b1, I see four sub-evaluations change. In order of the size of the change, those sub-evaluations are:

Psqt bonus. This gives a bonus to each piece based on what square it's on. The king gets a bigger bonus simply by being on b1 instead of c1.

Shelter weakness. The king gets a penalty on c1 because the adjacent d-pawn has moved, and gets no penalty on b1 because none of its adjacent pawns have moved.

Mobility bonus. On b1, the White pieces are slightly more mobile (the rooks can now move to c1 - yes, it counts the square for both rooks) and that gives a bonus.

Shelter storm. Black gets a bonus for the d5 pawn beginning to "storm" the White king if the king is on c1. With the king on b1, the d-pawn does not count as "storming" since it's no longer on an adjacent file to the king, and Black doesn't get this bonus.

All told, it adds up to about 0.5 evaluation points.
It seems that Stockfish is simply having a hard time coming up with a good plan here. At depth 27 it gives Rhf1 as the second-best move, but the line it gives starts with this.
rn1qkb1r/1p3pnp/p1p1p1p1/3pP3/3P2P1/2NBBQ1P/PPP2P2/2KR3R w kq - 0 13

1. Rhf1 Nd7 2. Kb1 a5 3. Rg1

But it doesn't exactly seem like the best sequence for making progress.


I used http://www.pychess.org/download/ and https://sourceforge.net/projects/scidvspc/.

Linux chess applications are generally free and open source.


ELO change of engine from pure material to very good evaluation

The currently best eval function is a leela net. At a single node, some leela nets are in the 2500 elo range. The drawback of course is that they are about 1000x slower than a SF eval (assuming a somewhat modern gpu, cpu). SF eval is obviously way weaker than this, but it wouldn't surprise me if is 500 elo stronger than a simple eval function.


What is the highest mobility score of a board without a checkmate, stalemate, or draw?

Sorry for the late answer, but here’s “my” suggestion of a total mobility 215 in a legal configuration. White has 216 total moves, minus away one for Black’s only legal move for total.

[FEN "1Q5R/4Q1K1/B1Q5/B4Q2/N2Q4/pQ4Q1/pn2Q3/krQ4R w - - 0 1"]

This position was originally created by William Shinkman as the record for the most mates in two. This position’s mobility will be very hard to beat, as it has no checkmate/stalemates in one, in addition to how the known maximum for any move is 218 contains so many checkmating/stalemating move that it won’t work here.


How to survive a Kingside Attack in Chess?

1st game

As in the second game you gained a good position out of the opening, exchanging the strong dark-squared bishop for a knight. Around move 25 black just seems better having the bishop pair, dominating the dark squares and having no apparent weaknesses.

Around move 25 you seem to start playing without clear plan. A natural plan would be to play a5-b4 (after preparation) which would make white's queenside pawns very weak
around move 30/31 could think of playing bxc4 31 Bxc4 a5 and work against the b2 pawn, or alternatively think of closing the kingside by playing e5 or even g5.
32.. a5 You certainly do not want to recapture a5xb4 (since this would give white a protected passed pawn on c4 the open a file...). That's why perhaps 32.. bxa3 33 Rxa3 a5 (and work against the b2 pawn) or 33 bxa3 (and white has weak a and c pawns) might have been better.
around move 35: Black is still better. You created a weak pawn on b2 and nothing should happen on the kingside since the white king is rather weak. Not sure whether black can achieve much from here. Perhaps you need to create some tactical ideas with a3 later on. First of all I would try to close the kingside/center with e5 which would also make the white bishop even weaker than it is. After black's e5, because of the weak pawn on e4 white is basically forced to respond with f5 after which nothing dangerous should happen to you on the kingside. If needed you can always play f6, g5 and defend the h pawn with heavy pieces from the 7th rank.
36..Rb8!? allows 37 Nf3 which makes closing the center more difficult
around move 40: you allowed the white knight to get to e5. Compare this to the position after blocking the center with black pawns on e5, f6, g5 where white would have virtually no counterplay. With the pinned pawn on e4 black should still be better but now you need to be more careful with tactics compared to the blocked kingside variation.
41..Qg7 Using a queen for the only purpose of defending a pawn  is not something you want to do, but seems to be the only normal  defense. A better (but not that easy to see) choice would have been to play 41..d3 42 Bxd3 Bd4 which prevents the knight sacrifice on g6 because now the square h8 (which in some lines allows the white queen to enter) is covered by the bishop.
43..a3 works here and would allow your rooks to get very active. After 44 bxa3 you can play 44..Rb1+ and white is lost if playing 45 Bxb1
44..hxg6 loses. You could have tried fxe4, but even then white should be much better.

Summary: Out of the opening black had a good position and also created some targets (weak pawns) on the queenside. Intentionally or not intentionally (?) black chose to not close the kingside and to keep the pawn structure flexible. This is not necessarily a bad idea considering the weak white king. Basically you made a choice between: (a) closing the kingside and playing safely for a win (with admittedly decent drawing chances for white) or (b) Keeping the structure flexible allowing additional options in the center in case black cannot achieve anything on the queenside. Unfortunately, black then lost to a tactics (Nxg6). I would not really consider this game an example for a kingside attack, because basically you lost because of that tactics only.

2nd game

You achieved a quite decent position around move 12, having exchanged the strong white bishop on d3 and created a weak pawn on c3. There does not seem to be any attack on the king side threatened soon. Black should be slightly better at that point.

At move 13 you should consider how to continue your play on the queenside. Obviously a rook or two will go on the c-file, the knight seems to have a nice square on c4, but also you might want to use a knight to attack the pawn on c3 from b5 or a4. The queen would have a good square on a5 from where it attacks the pawns on a2 and c3. You started with 13 .. Rc8, which is certainly not wrong, but Qa5 might be more correct as it un-pins the knight on e7 and prevents being locking in the queen after b6.
14 .. b6 makes your play on the queenside much more difficult as your queen cannot go to a5 anymore. And also it prevents activating rooks via Rc6-Rb6 or Ra6. 14.. Na5 might have been better.
18 .. h5 could have been an idea in order to prevent white playing g4.
19 ... Nb2 seems useless unless you want to move the knight to a4.
Activating the queen via Qe7-Qa3 (this does not work yet because after g4 you'd lose the knight on f5, but could be prepared, with h5) or via Qb7-Qa6-Qa3 or Qa5 could be a long-term plan. But first of all you really need  to prevent white from playing g4-f5 here, which is basically the only way for white to gain any counter-play. 19 .. h5 seems like a logical move here, unless you want to go for a passive setup with g6, Ng7 which does not seem attractive to me.
23 ... Ng6!? does not seem like a good square to me. White will want to play f5 anyway and this just gives him an extra tempo since the knight will be attacked.
24 ... Ne7 You noticed your mistake, but as with the Nb2-Nc4 maneuver, you are wasting tempi in a position where you should either play very strongly on the queenside or think of defenses.
25 ... f6? Not a good move as it weakens the light squares and gives the bad bishop on g3 lots of squares if white plays  exf6. Your best option might have been to play with rook against two minor pieces after 25..exf5 26 gxf5 Nxf5 27 Qxf5 Ne3 With the weak white bishop and weak pawn on c3 chances might not have been that bad.
27 .. Tcd8? White is threatening f6 which does look pretty deadly. 27 ... Qc5+ with the idea to play Qe3 looks like an option since exchange of queens would be good for black. If white responds to the check with 28 Bf2 this would block the rook on f1 from supporting the f6 push and would give black another tempo to play Qc7 attacking the e5 pawn again. In fact white's only good option might be to return with the bishop to g3, making this a move repetition..
28 f6 Black is basically lost after this move, so there is no point analyzing further.

Summary: Out of the opening black had a good position. You did not really get anywhere on the queenside though (perhaps because of b6) and also you wasted a few tempi moving knights back and forth. White has basically only one plan in this position which is a kingside attack with g4-f5-f6... When breaking through on the queenside seemed impossible you should have focused on how to prevent white from carrying out this plan. You missed two defensive tactics which could have given you a draw.

A few ideas on what to do in general against this plan in positions like this:

Play h5 to prevent g4 and to strengthen the position of your knight on f5. If white plays h3 with the idea to play g4 sometimes you can play h4 or you can go for a setup (after g4 hxg4 hxg4) with knights on h6 and e7 and queen on d7 all working against f5
Put a rook on the 6th rank (c6 in your case) which could help to prevent f6 later
Escape with the king to the center
Open the center. This is kind of what you tried playing 25 .. f6. However this would have been more effective e.g. with the rook from c8 on e8 defending the knight and putting pressure on the center. Generally opening a center is a good response to a pawn storm.
Be faster on the queenside.

What should you do?

Looking at the two games, I would say that in the second you really encountered a kingside attack which is not easy to defend against and is perfectly possible to lose even with best play. There is no reason that you should lose to the first game's "kingside attack" though, because: you have very good counterplay (b2, e4 pawns), have the option of preventing any of white's activity by closing the center/kingside, don't have many threats to defend against.

Some ideas on how to improve your play against kingside attacks:

Work on your tactics, which is always a good idea. In game 1 you missed 41..d3 and 43..a3; in game 2 you missed 27..Qc5+ and the tactics around moves 25-27 (exchange of two pieces for a rook).
You could also think about changing your opening repertoire to playing for instance 1 e4 e5 which does not run into problems with such kingside attacks as easily. In many of the Sicilians you do run into such kingside pawn storms, similarly in many French and in the Modern/Pirc.
Study how masters handle kingside attacks for pawn structures that occur in your games.
Consider whether you can close the pawn structure on the kingside.
Be quicker with your queenside counterplay (don't fool around).


Your last move 13.Bxf5 leaves you with a much smaller advantage than 13.gxf5, that's what the engine is counting as a "blunder" (some of the previous moves have smaller mistakes, but none of them should be counted as "blunders")


Is the queens gambit declined getting more popular than the slav?

It seems to be that the QGD is regaining some popularity at the top level due to theory advancing. I don't think that says anything about the overall popularity of the two openings though (i.e., including all players).

The increase in engines' powers have made playing the semi-slav a very treacherous choice. There's a lot more that super GMs need to know now in order to stay in the game. Meanwhile, the slav can result in Black getting squeezed, and in general super GMs avoid openings like this. The QGD can be thought of as a safe "middle-ground", in which Black can gain equality with a bit of precise play. This is the kind of Black opening that many super GMs tend to like nowadays.

Overall though, none of these openings have lost any validity at the non-top level.


What is it called when opposite colored pawns up against each other?

With the exception of Hans Kmoch's attempt to give it a name, which never caught on (I have never seen anyone else use it anywhere), they really do not have a name that I have even seen.

I probably have seen this referred to mostly as "two opposing pawns", but that is really just English rather than a specific chess term.


Well, after your update I come to the conclusion that these signs are used by the author to mark the omission of the notation of the respective move by White.

This is not a common usage of them, and I have never seen it before. It should be documented somewhere at the beginning or end of the book. But I'd not be surprised  if it's not, since it doesn't reflect a healthy common sense to use the check symbol of all things for this purpose to begin with..


Is there ant database that will return the reversed position?

Chessbase opening trees (ctg) detect white/black transpositions.  My database has 59 games starting 1.e3, 9 games where black answered 1...e5, but then 28000+ games for 2.e4.


Even all 8 of them, if you manage to get them to the opposite back rank. Let's look at the relevant part in the Laws of Chess:

  3.7e When a player, having the move, plays a pawn to the rank furthest from its starting position, he must exchange that pawn as part of the same move for a new queen, rook, bishop or knight of the same colour on the intended square of arrival.
  This is called the square of ‘promotion’. The player's choice is not restricted to pieces that have been captured previously. This exchange of a pawn for another piece is called promotion, and the effect of the new piece is immediate.

The bold emphasis is my own and probably the important part for resolving your confusion.


Are there any very lopsided scores in openings at lower levels?

In order to answer your question, I put together a database archive of 30000+ games played in over-the-board tournaments where both players were rated less than 2000.  Only one game had the Halloween, and there were few Traxlers.  Black died quickly in a handful of Fried Liver Attacks.  There were no Parhams 1.e4 e5 2.Qh5 nor Fool's mates.

The Triangle/Noteboom complex scored very well for Black as did the Benko Gambit.  1.d4 d5 2.Nc3?! looked to be a bust, and the Sicilian Grand Prix Attack 1.e4 c5 2.f4?! didn't fare well for White.  In the Ruy Lopez, the Steinitz defence 3...d6?! and Cozio 3...Nge7?! led to a lot of Black losses.  Rubinstein's line in the French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 dxe4?! didn't do well either.  A lot of patzers fell for 1.d4 Nf6 2.c4 d5?! 3.cxd5! and ended up getting overrun.  1.e4 c6 2.c4! did well against the Caro-Kann.


is it legal to reply with resignation when a draw is offered?

Of course. This is all that the FIDE Laws of Chess has to say about resignation:

5.1.2 The game is won by the player whose opponent declares he resigns. This immediately ends the game.

You can resign at any time during the game. It doesn't even need to be your turn. I have done this. I once played a move that would blunder my queen, realized as I pressed the clock and immediately resigned before my opponent could play the move I missed.

is it considered bad sportsmanship ... to resign at a draw offer?

No. Why should it be? There are some circumstances where it could be considered good sportsmanship. Suppose, in the last round of a tournament, player A requires just a draw to win the tournament outright and offers his opponent, player B, a draw in a completely winning position. Player B could accept the draw but it might be more sporting to just resign.


Knight sacrifice performed by Deep Blue against Garry Kasparov

History of this line is interesting. People used to think it's good for white, maybe majority still do as well as openings books do. But in correspondence database I use there are four games with Nxe6 fxe6 and black scored two wins and two draws out of four games. The wins are from 2012 and 2013. I know a lot of white players avoiding the sacrifice these days as it is easy to lose even against much weaker opposition while it doesn't even have the objective quality. Black play is easier and more obvious. I don't like White's position, I like Black here. It is too closed without direct threats for such a material investment. I know mainly the defensive plans for black here as it is in my repertoire, ok white try to play on e-file, disrupt you with Ne5 and f7 fork threat, may want to play c5 with B/Qa5+ sometimes and even b2-b4-b5 as black is undeveloped for quite some time. It is positional sacrifice and very interesting one.


Are there mobile chess tutoring/training apps for Android or iPhone?

Here are my Chess apps for Android:

iChess — lots of chess tactics to solve, all offline. You can also load your own PGN or purchase recent tactics based on openings, or from recent games.

Chess Book Study — a very innovative app that shows a board and an eBook in the same screen. It makes it easy to study chess books. You can even dictate and the moves are made on the board.

Analyze This — analyze a position with two engines, simultaneously!


Bad: They can't defend each other like adjacent pawns can.

Good: They give you an extra open file for your rooks.

Usually the bad outweighs the good, but there are a zillion exceptions. Most beginners are overly afraid of having doubled pawns.


Black opening sequence that is equally solid versus d4 and e4

You could try Owen's defense, which is very much under-represented in all levels off chess in my opinion. Smirnov's 2-part series is nice and clear (although sometimes slightly over-simplified maybe), and he has another 2-part series about using this strategic system with the white pieces.
I would recommend playing the Colle-Zukertort at white a bit, the ideas are definitely useful for the b6/b3 systems. This also provides a very comfortable and active setup to shoot for as black when your opponent does not put a pawn on e4. The themes from the Breaking Stereotypes series provide some nice complementary insights for these positions as well.

Another option is the Sniper, which is a lot of fun to play and is maybe even more systematic as far as strategical planning is concerned (get king's bishop to the longest diagonal by playing 1. .. g6 2. .. Bg7, then play for central and queen-side activity via the dark squares by playing 3. .. c5) but it's significantly less forced which means the total amount of relevant theory is a lot larger. Also you might end up in some fairly theoretical positions, or positions that are really though to play unprepared. Super flexible though.

And then there's the Hedgehog, which is by far the most systematic and repeatable chess opening I know of. It's not uncommon to play the same 10 to 13 opening moves five times in row or even more, without your opponent even following theoretical variations.
   (btw John Bartholomew is excellent at teaching chess through actual understanding so that's an unrelated recommendation)


How do I change Stockfish's Engine Parameters?

As shown in the screenshot below. Goto Tools -> Analysis Engines -> Edit. You'll see a UCI configure dialog. In this example, I had another engine but the idea remains the same.


R+3P vs B+N+3P ending. Win or draw, and plans for both players

Here's what my sources say about this endgame.

Müller, Lamprecht, Fundamental Chess Endings:

  With three against three on one wing the defender is usually able to hold on.

 [Title "Mueller vs Yusupov, Hamburg SKA (1991), after 66... Ba5"]
 [fen "8/5p2/6p1/b1n4p/2k2P1P/4K1P1/1R6/8 w - - 0 0"]

1. f5 Bc3 2. Rg2 gxf5 3. Kf4 Kd5 4. Kxf5 Ne4 5. g4 Nd6+ 6. Kf4 Be5+ 7. Kf3 hxg4+ 8. Rxg4 Ke6 9. h5 Nf5 10. Rg1 Kf6 11. Rg8 Nh6 12. Rg1 Kf5 13. Rg2 Bf4 14. Rg1 Bg5 15. Rg2 Bf4 16. Rg1 f6 17. Rg7 Bg5 18. Kg3 Ng4 19. Rg8 Ne5 20. Rg7 Bh6 21. Rg8 Nd3 22. Kh4 Nf4 23. Rh8 Bg5+ 24. Kg3 Ne6 25. Rg8 Bh6 26. Rg6 Bf4+ 27. Kf2 Bg5 28. Rg8 Nf4 29. Rh8 Kg4 30. h6 Kh5 31. h7 Kh6 32. Kf3 Ng6 33. Ra8 Kxh7 34. Kg4 Ne7 35. Kh5 Kg7 36. Ra5 Bf4 37. Ra6 Be5 38. Rb6 Kf7 39. Ra6 Nc8 40. Rc6 Nd6 41. Ra6 Ne4 42. Kg4 Kg6 43. Rc6 Bd6 44. Ra6 f5+ 45. Kf3 Kf6 46. Ke3 Kg5 47. Kf3 Nd2+ 48. Ke2 Bf4 49. Ra4 Kg4

  White should just sit and wait in his fortress. However, he decided to start some misguided activity.

Dvoretsky, Dvoretsky's Endgame Manual:

  If both sides have three pawns placed on the same wing, then the defender may hope for a draw (only if, of course, the pawn structure is devoid of grave flaws).

  [He then analyses the endgames in Capablanca vs Lasker, St Petersburg (1914) and Timman vs Karpov, Bugojno (1980).]

Flear, Practical Endgame Play - beyond the basics:

  The case where all pawns are on the same flank is interesting as the result isn't always evident. However, a general rule could be that the bishop and knight require a target in order to convert their superiority.

  [He then uses Ponomariov vs Sasikiran, Biel (2004) and the aforementioned Timman vs Karpov, Bugojno (1980) as examples.]


Is Anand possibly cheating (the metal detector)?

The organizers certainly noticed the watch, if you did. Therefore, since it was allowed at the match, they must have determined that it could not aid chess play in any way.

Their reasoning should be simple: either the watch communicates with an outside device in order to signal the player, or else the watch does all chess calculation itself.

Communication with an outside device requires radiation which is easily monitored by a counter-cheating system, and a watch that could a) internally calculate chess moves at such a strength as to aid an elite human, b) accurately yet undetectably signal the wearer from an analog clockface, and c) accurately read the chess board, is currently technologically impossible.

Hence, dismantling the watch is unnecessary until technology allows undetectable wireless communication or a computer of the described caliber becomes even a remote possibility.


Is there a way (or tool) to convert games in PGN to notations like the one in the description?

PGN is for game notation, i.e. the whole game. You can use the FEN notation by creating the position on chessvideos.tv FEN generator site and then use the code to input this into Fritz or your preferred software. Code is on the top right. 3k4/8/3K3R/8/8/8/8/8 is the code for the position you gave.


I think, yesterday, I have answered such a question here.
I am just pasting the answer and adding a few resources to it. You should keep these in your mind.

Smooth Transition: As per other answers, I think you should try 15+0 [Rapid] >> 10+5 >> 10+0 >> 5+5 / 5+3 [Blitz] >> 5+0 >> 3+2 >> 3+0 >> 2+1[Bullet] >> 1+0, in following manner: If you can complete (win/lose) 10 games in a row within the given time then go for the next tier.

One Opening man: Instead of experimenting with different openings, you must stick with a single one and simultaneously have to study it deeply. After studying a line properly, set a target to play first 10 moves within 10 sec. If you follow a single line (eg., 1.d4) for more than 100 games; then you will find that it is quite easy for you to reply not only fast but also accurate. And it will help you significantly in time management.

Pre moving: After "mastering" an opening, try to pre-move [This is crucial in the bullet, not in blitz]. Just make sure to play first 10 moves within 5 seconds!! and you will rock on bullet [at least below 1500 tier].

Pattern Recognition in Middlegame: A simple way to play ultrafast middlegame is pattern recognition (eg., if both King and Queen are in the same diagonal, then try to find your bishop to set a "Royal Fork"). The only way to achieve this is by practicing a lot of puzzles. So, be prepared to try at least 20 puzzles (If possible 50) each day.

Accurate Endgames: "All's well that ends well." So, be focused at your endgame. First, master the checkmate patterns (Staircase mate, smothered mate etc.) and then try the comparatively advance theory (like opposition). If you are already good at endgame, then invite your opponent directly from the opening, by exchanging valuable pieces early in the game.

Here are a few resources you can check:
Beginners training kit at lichess.
Tactics training at Blitz-tactics
Puzzles at lichess
Hope it helps. Good luck.


One sure-fire way is for you to buy your own copy of Swiss Manager, the pairing software used in this particular case, and reproduce the tournament and then do the next round pairing once all the results are in. The light version of Swiss Manager, which you could use since there are fewer than 60 players, costs 75 euros.

Alternatively you could try and do the pairing by hand yourself. For this you would need to read, understand and follow the FIDE Swiss rules for pairing.


Have famous grandmasters ever been checkmated?

The most recent super Grandmaster level checkmate I can think of is the game Wesley So vs Hikaru Nakamura, Sinquefield, Cup August 2015.

[White "Wesley So"]
[Black "Hikaru Nakamura"]
[Result "0-1"]
[FEN ""]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nc6 8. d5
Ne7 9. Ne1 Nd7 10. f3 f5 11. Be3 f4 12. Bf2 g5 13. Nd3 Ng6 14. c5 Nf6 15. Rc1
Rf7 16. Kh1 h5 17. cxd6 cxd6 18. Nb5 a6 19. Na3 b5 20. Rc6 g4 21. Qc2 Qf8 22.
Rc1 Bd7 23. Rc7 Bh6 24. Be1 h4 25. fxg4 f3 26. gxf3 Nxe4 27. Rd1 Rxf3 28.
Rxd7 Rf1+ 29. Kg2 Be3 30. Bg3 hxg3 31. Rxf1 Nh4+ 32. Kh3 Qh6 33. g5 Nxg5+ 34.
Kg4 Nhf3 35. Nf2 Qh4+ 36. Kf5 Rf8+ 37. Kg6 Rf6+ 38. Kxf6 Ne4+ 39. Kg6 Qg5#


The exchange variation, provided you continue with the Panov attack, is actually very tactical and aggressive. If you are looking for something quite different, I suggest what I play: the advance variation with an early h4 push.

That would be:

[StartPly "7"]
[FEN ""]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. h4

on this website you can find some of the more common approaches to the variation. More than just a tactical sideline, it is extremely tricky, so you should know a few things before going into this mess. There are many lines where black has "only moves", but it is thought to not be very promising because in the end (after like 20 forced moves) black stands ok.

The thing is, most players who face this line have never seen it before, and they play the natural moves, falling into one of the hundred pitfalls available. An example is if black simply ignores h4 and plays 4. ... e6. After 5. g4, his bishop is trapped. This is only the first trap that you set (and on blitz, it's a very common one). Another one occurs after:

[StartPly "7"]
[FEN ""]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. h4 h6 5. g4 Bh7 6. e6 fxe6 7. Bd3 Bxd3 8. Qxd3 Qd6 9. f4 Nd7 10. Nf3 O-O-O 11. Ne5 Nxe5 12. fxe5 Qd7 13. h5,

where black simply played normal moves to advance e5 and get rid of his doubled pawns, but in the end is playing without the three pieces of the kingside. I've played this line myself a couple of weeks ago, with devastating effect (I won on 20 moves, the idea is to simply double/triple on the f file).

This is just a few flavors of this sideline, check it out for yourself and see if the positions arising from it suit you.