Help with game phase identification I'm working on a chess AI for a school project and I am looking into ways to identify the current phase of a board, meaning the opening, middlegame, and  endgame. I have seen an article explaining Tapered Evaluation, however I don't really understand what the point of this is. I want to be able to change my overall board evaluation heuristic depending on what state the game is in. This way, in the middlegame, I can prioritize king protection and development and other strategies.

I think you don't need this. You shift from opening to middle game when your opening book for this line runs out.
The middle-end phase is less relevant in AI, and your algorithm will handle those the same. You could define a line, e.g. when your search depth could be increased over some threshold, because the board has only a handful of pieces left, but I don't think it's an important change.


Are there any current studies on the physical effects of playing chess? In the 50s Eliot Hearst printed the results of a study in "Chess Life and Review" (A private publication by I A Horowitz editor later merged into the USCF's monthly magazine, and later renamed "Chess Life") that showed the impact playing chess had on things like BP and heart rate.

Are there any more current studies that elaborate on those and extend the study to other ways chess affects humans?

Especially interested in more long term items as well as game time impacts that one could prepare for in advance.

I found a study from 2015 that seems to go into a lot of various aspects of chess and how it affects us physically.

"Biochemistry and Psychology of Chess and Classical Physical Exercise:Concurring or Conflicting Evidence?"

I am going to block-quote their "Abstract", which gives an overview, but you might want to read the full paper, which is only 10 pages long. It is fairly interesting.

  Abstract

  Chess is a competitive sport in the classical meaning of the word. One
  of the most important factors for chess and sport competence is the
  accumulated time of training. In order to obtain a high level of
  competence, chess layers and athletes alike must spend up 10 years of
  specific training.

  In chess and classical sport energy needed for brain activity is first
  derived from glycogen stores in brain, muscles and liver and later
  from adipose tissue. Both, chess and classical sport rely on shared
  energy from glycogen and fat.When  the  brain  needs  additional
  energy,  muscles  and  liver  share  energy  with  the  brain.  When
  muscles  need additional energy, brain complies with the request of
  muscles. Energy expenditure, O2 uptake and CO2 production during chess
  games are similar to those obtained during a marathon. Mental and
  physical fatigue begin with similar metabolic states: deprivation of
  glycogen. During competitive chess, athletes must be in good physical
  condition.

  Mental profiles of chess players and other athletes correlate with
  processes such as attention, conflict control,memory, motivation and
  recognition.

  In chess there exists no gender-specific excellence; glycogen
  availability, however, is less developed in female chess players.

  In chess and in classical sports, the brain, spinal cord, nerves and
  muscles cooperate in complete harmony. The brain commands everything:
  in chess the figures, in sport the cellular receptors (baro-,
  lactate-, gluco-, metabo-,chemo-, thermo-, respiratory-) “send”
  signals via eyes or metabolic changes to the brain. The brain then
  decides,what to do: in chess, the player moves a figure; in sports,
  muscles react according to demand.

  Physical exercise or chess must be defined by a motor activity
  completely controlled by the central nervous system (CNS) in
  combination with a specific competence. In chess as well as in
  physical exercise, physical stress prepares brain to cognitive
  stimulation.

  With respect to biochemical, physiological, neuronal and psychological
  aspects, chess is equals classical physical exercise and must be
  recognized as sport.

Here is another article, "7 Surprising Health Benefits of Playing Chess", that lists various benefits that can are certainly physically related, and cites the sources.


A confusing situation-is this stalemate? Today I played a game, and it was my turn in the endgame.

I had only one pawn, which is blocked, and my king left. But my king could move only to a single square legally, as it would otherwise be in check. However, on the next move of mine, I had to put my king back on the square that it came from. I had to repeat these moves 8 or 9 times, with no another moves available. My king was stuck within those 2 squares.

I was confused, and I still am. Eventually, my opponent promoted a pawn to a queen, and afterward, in 2-3 moves, he checkmated me.

Can anyone explain this type of situation? Is it stalemate, or something else?

A stalemate is when, during your turn, you cannot make any legal move. The game then stops as a draw.

As long as you can make a legal move, with any piece, it's not a stalemate. Therefore the situation that you have described is not stalemate, as you had legal moves every single turn.

There isn’t really a name for the situation that you are in, but it is best called a repetition for simplicity’s sake.

Now, if your opponent also made the same moves as well every single time, and it were a tournament it would be called a threefold repetition and you could claim a draw. But only you are repeating your moves.


Best way to prepare files with openings for future use I am looking for advice how to prepare opening, so i could easily skim over it after a while. Create databases for every opening with analyzed games? But some positions can occur after different openings. Create artificial games per opening with lots of variation and store in one database? Should i add notes?

I am limited to SCID and Chessx because i use Linux. But general ideas a highly welcomed too.

Here I will describe the usual and probably best way of preparing an opening repertoire.

Black

The usual way to prepare an opening repertoire with black is:

Depending on your style of play, skim through several games with different openings that suit your style of play and choose one (opening) for every starting move.
Starting with the most played (usually 1.e4) have a general look at the main line and a couple of important sidelines of your preferred defense. Choose a line that you like and feel comfortable with the position. Bear in mind that whenever black can deviate, you may only choose one deviation to begin with, but whenever white can deviate you must have a look at all (or at least most of) the deviations.
Build up an personalized file with your choice of opening repertoire. This should include the line you have chosen, the possible deviations for white and your answers. When theory ends, you should add a sample game (or even two if possible) with a relevant idea or position on said subline. Concerning the notes, if you find an annotated game (the annotator having a good level, preferably GM and that the game was his) on your pet line (or even if it's not your pet line) with relevant commentaries, it is surely a good idea to include it in your repertoire.
This is not always strictly necessary since most people only play for fun, but in general it is useful to check (now or when choosing the lines you want to play) that your repertoire is sound, or at least playable.
Repeat 2. and 3. for the rest of the opening moves.

Example

Despite the huge variety of opening moves, you may choose intelligently your opening repertoire so that you only have to prepare a couple of main defenses and get away with playing similar positions with different move openings. The main opening moves are 1.e4 and 1.d4.

I am a tactical player, so against 1.e4 I will play the Sicilian Dragon. Against every possible attack by white (Smith-Morra, Classical variation, Yugoslav attack, Russian system and so on) I will prepare the main line in almost all of them, since it is more probable that the'll play into may preparation that way. Particularly, on the Yugoslav attack I will play the Chinese Dragon (Rb8 instead of Rc8 at some point). I will play Be6 aginst the Classical variation. I will play e6 and Nge7 against the Closed Sicilian and so on. I will prepare a file on this defense.

Following this same tactical ideas, and because it also is a fianchetto defense (and I am used to having my bishop on g7 because of my main defense against 1.e4) I will play the Grunfeld defense against 1.d4. The main attacks are (of the Exchange Variation) Bc4, Be3, Nf3 and Rb1, Qc3 and others, and againts all of them I will choose a more positional setup (Bg7, c5, Nc6, Bd7 and b6 on the main line, and the ideas are similar on the rest), as the opening is already quite tactical to need to memorize hundreds of forced lines. I won't lack of tactical opportunities. I will prepare another file on this defense.

Now, because of my opening choice, against 1.c4 I can use a Sicilian Dragon setup (the symmetrical English), so I won't have to choose another defense. Moreover, against 1.Nf3 I can also play 1... c5 and enter similar positions to the ones I know. This means that my whole repertoire is reduced to "only" two defenses.

White

The usual way to prepare an opening repertoire with white is:

Depending on your style of play, choose an opening move. The general guidelines for this are that 1.e4 is for tactical players, 1.d4 and 1.c4 are for positional players. This however highly depends on the position the defender chooses. Other opening moves are, in general, not as good as those three.
Make a list of the main defenses to the opening move you have chosen.
Starting with the most commonly played, have a general look at the main line and a couple of important sidelines. Choose a line that you like and feel comfortable with the position. Bear in mind that whenever white can deviate, you may only choose one deviation to begin with, but whenever black can deviate you must have a look at all (or at least most of) the deviations. This is the exact opposite that happened with your repertoire with black.
Same as 3. before, build up a repertoire file. The same comment on 4. applies, soundness of the lines are generally good advice.
Repeat 3. and 4. on this list for every other defense you may face, going through the list starting with the more common.

Example

As I am a tactical player, I will open the game with 1.e4. The main defenses I will face are: Sicilians, e5 answers, French, Caro-Kann, Pirc and Scandinavian.

Every one of them has his own body of theory, but I will choose the open Sicilian (trying to play more or less main lines against all the Sicilians), the Yugoslav attack against the Dragon, the Richter-Rauzer attack against the Classical, the English attack against the Najdorf and Scheveningen and so on. I will also play the Scotch against 1... e5 since it's a very tactical opening. I will play the Tarrasch Nf4 against the French, which is a very wild line. The Caveman attack against the Caro-Kann (from the Advance variation, an early h4), the Hungarian attack against the Pirc and the main line against the Scandinavian will be the rest of my repertoire.

Of course, this has to be well researched and saved in a file.

Conclusion

This task should not be extremely difficult, but it will be long. I suggest you take a look at this video, as his main purpose is to teach how to use SCID to develop an opening repertoire. Choose wisely, as good choices will serve you well for the rest of your chess life, whereas poor ones will have to be changed over and over.


What is the point value of each chess piece? I would like to know the point values of each chess piece. I forgot the values because I have not used that system in quite a long time.

General consensus values chess pieces as follows:

Pawn = 1 point
Knight = 3 points
Bishop = 3 points
Rook = 5 points
Queen = 9 points

However, you should consider this valuation scheme (as well as any valuation scheme) to be very vague, to the point where it is almost sloppy to assume it is correct in any specific position. For instance, two bishops together are often valued higher than 3+3, sometimes 6.5 or 7. Or a passed and advanced pawn may easily be worth a piece, especially when connected with another pawn. Rooks, bishops, and queens are worth less than normal when the position is closed, whereas knights thrive in such positions. When the position has clear lanes for the long-range pieces, the knight is less outstanding.

Of interest, too, is the valuation of the king's tactical strength. The king is generally valued between 3 and 4 points, slightly higher than a knight or bishop. Of course, this valuation is meaningless when it comes to calculating exchanges.

Wikipedia's article on this topic is well-referenced and extensive. There is a table listing various valuation schemes, both historical and modern, and an average of all schemes in the table is given as follows:

Pawn = 1 point
Knight = 3.2 points
Bishop = 3.3 points
Rook = 5.2 points
Queen = 9.6 points
King = 3.5 points


What openings typify 21st century chess? What openings are particularly typical of 21st century chess so far?  To be more clear, which openings are particularly popular in the 21st century relative to the 20th century?  For example, certain hypermodern defenses became a lot more popular in the latter half of the 20th century relative to the first half of the 20th century.

Here are a few openings that seem to be played more often in the last decade than previously.  This is just based on my recollection, so please correct any errors or add any other openings.

Catalan Opening
The last few major matches have all featured the Catalan: Anand-Topalov, as well as the candidates matches leading up to the World Championship 2012. The Grandmaster Repertoire by Boris Avrukh has also contributed to the recent popularity.
Berlin Wall
Kramnik brought this opening to the forefront when he used it with devastating effect against Kasparov.  The queen-less middlegame has been deeply studied since the match in 2000.  This line is partially responsible for the rise of 1. d4 and the fall of 1. e4 in the last decade.
Grünfeld Defense
While the Grünfeld was played fairly consistently throughout the 20th century, only recently has it become the main weapon for black when playing for a win against 1. d4.  The Grünfeld doesn't surrender the center like the King's Indian Defense, and it has become more popular the more it is studied, as opposed to the Nimzo-Indian which has fallen by the wayside as the Qc2 lines have been examined.

Other openings that have been featured in high level games have been the Slav Defense and, as always, the Sicilian.  I omitted these openings because, while new lines are always being developed, these openings have been popular consistently for a long time.

Additionally, as I mentioned in my comment, some gambits have also seen a revival.  The Morra Gambit, for instance, has come back to high level play and several books about it have been written.  The Evan's Gambit is another opening played at all levels.


App Mis-calculated Checkmate? How is this checkmate? The King isn't even in check! Am I missing something, or did the chess app goof up?

If the app first displayed checkmate in that position, then it miscalculated.

But as Phonon noted, the app could have displayed checkmate in a previous (future) position, and then you went back a few moves. In that case it's not a miscalculation per se, but just a bug in the UI.


Opening with Nf3 - beginner I came across the opening Nf3 wich I find very beatiful. I know that it could lead to the Réti opening. My question is: beside the Réti opening what are the most commun openings following the Nf3 and what are considered to be the weackness of this move?

1.Nf3 can transpose into almost any opening depending on your opponent and you, it is ultra-flexible.

Just to show its flexibility:

If you play 1.Nf3 and your opponent responds with 1...d5 then you can play 2.c4 to go into the Reti or 2.g3 to maintain flexibility and play the King's Indian Attack or some other pseudo-slav with Bf5/g4, all this stuff. Or you could play 2.d4 and it would transpose to a Queen's Pawn opening then from that point it would be a different story.

The same goes with 1.Nf3 Nf6 2.d4 where it transposes to a queen's pawn opening with an early Nf3.

As user3671618 said you could also go into King's Pawn openings after 1.Nf3 c5 2.e4 which would be a Sicilian.

Also after 1.Nf3 g6 2.e4 would also transpose to a modern.

The point is that most Grandmasters use 1.Nf3 as a trans positional tool, like for example to get to the Catalan after 1.Nf3 d5 2.g3 Nf6 3.Bg2 e6 4.0-0 Be7 5.c4 and later d4 and White has avoided all the Bb4+ problems associated with employing the Catalan through its classical move order which is out of the scope of this post. Of Course Black does not have to play in such fashion and the drawback of the early fianchetto is that Black usually has the luxury of bringing his dark squared bishop out instead of blocking it in via e6.

1.Nf3 is mainly used as an ultra-flexible trans-positional tool to avoid certain lines. For example after 1.Nf3 d5 many grandmasters play 2.d4 and so they avoid all the King's Indian, Grunfeld, Nimzo, Benoni, Benko systems as the pawn on d5 is already committed. One of the most famous practitioners of this approach was GM Alexander Wojtkiewicz, there is a famous book series written on him titled Wojo's Weapons, he played 1.Nf3 exclusively as a trans-positional tool.

1.Nf3 is just as good as 1.e4 and 1.d4, this can be best explained by the simple opening principle that it develops a Kingside piece towards the center! Former World Champion Vladimir Kramnnik is another 1.Nf3 devotee and many of the World's best players employ it in their repertoires.

The drawbacks are that you just cut out so many openings and lose many options, but this is why many 1.Nf3 players play it! They want to avoid the problematic defenses associated with 1.d4 and 1.e4. It is mainly used as a move-order trick and to maintain flexibility.

But I would recommend for a beginner not to play 1.Nf3 as many times you would have to venture into the English and complex sub-variations of other openings which I believe contain so many subtle-move orders so 1.d4 or 1.e4 are much better in improving your play since they are much easier to understand for the improving amateur and you gain a greater wider variety of positions from them which exposes you to many different themes and ideas and would contribute greater to your improvement.


Who is this person in this image? I think many chess players saw this image when playing older versions of Fritz as the option "coach is watching." But out of curiosity, who is the person in the image? Is he a grandmaster?

Looks like its a stock image: the oldest source of the image I could find from 2008: http://www.grafamania.net/clipart/6201-digital-vision-dv297surreal-business.html


Building up a dataset for image recognition of hand-written scoresheets I am trying to build up a training dataset to train a convolutional neural network (well, the pipeline will probably be a little more complex, but probably a CNN will be at its core) to convert handwritten scoresheets into PGN.
Does anybody have a (larger) body of scoresheet images + respective PGNs or knows which persons/entities could potentially provide those? Since score sheet formats vary widely between countries and federations I'd be interested in a great variety of them.

Does anybody have a (larger) body of scoresheet images + respective
PGNs or knows which persons/entities could potentially provide those?

All FIDE rated tournaments where norms are available (so must have a minimum number of GMs, IMs and federations playing in the tournament) are required to submit PGNs of games played to FIDE to ensure the integrity of titles. This means that all such tournaments will have a stack of scoresheets which have to be entered into the computer and submitted to FIDE. This means that arbiters at such tournaments who have responsibility for inputting are likely to have large numbers of such scoresheets.
Aside: As somebody who has been the chief arbiter in a norm tournament I can tell you that such a program, if successful, would be very, very welcome.
Additionally some federations, leagues and tournaments have policies of trying to submit PGNs for FIDE rated tournaments where norms are not available. The English Chess Federation is one such and in it the 4NCL (4 nations chess league) are very good at publishing PGNs.
Entering scoresheets into the computer is often difficult and can be boring. Some people (me, for instance) are not that good at processing a stack of, say, 100 scoresheets. Other people are very good indeed. In England there is one star who is quite brilliant. That is International Arbiter and IM Jack Rudd. I don't know what he does with scoresheets after he is finished but if he doesn't throw them away he will likely have a very large pile. You will see him on the list of arbiters officiating at mega tournaments like Gibraltar and Isle of Man because he is so good at this.
To be useful your program will need to handle languages other than English, including languages which are written from right-to-left like Arabic, Hebrew and Thai.
I should add that arbiters are not particularly strict when it comes to enforcing rules around scoresheet legibility and entering the moves correctly. For instance, although the abbreviations for the pieces may be in your native language, the files must be written in English ("a" through "h") however many players use their own alphabets for these and I don't think I have ever come across an arbiter who enforces this.
Finally, here are a couple of scoresheets from a tournament where I was chief arbiter a few years ago.

Surprisingly this is one of the more legible scoresheets from this player. He did, though, use descriptive rather than algebraic notation.
Here is a more legal one (algebraic)

I wish you a lot of luck with your project but I don't think you really understand the problem. Playing chess can generate very high levels of stress in the players and this often leads to problems with how they write the moves.
PS You can download the pgn file for the tournament these games came from from the FIDE website here.


How important is playing chess games while you are working on to improve your chess? I am trying to improve my chess and I spend about one hour in morning doing tactics and around one and half hour in evening studying endgames.

I am following this schedule for about 2 months now and during this time I have not played any chess games.
Problem is if  I play chess i get less time to look into chess studies.

My thought process is as I am losing many games in lichess and all, I will finish this studies (at least to an extend) and will go back to play chess with my new knowledge in couple of months.

Am I doing this wrong?

How can I go about this?

Personally, I think that you have a very solid plan. When I was up-and-coming, I would study a lot every day, but I would only play about two tournaments a year. Up to a certain point, I would pick up about 200 rating points per tournament in the beginning, and later about 100. Of course, as I got over 2000, that slowed down some. Back then, we did not have the Internet, so I would also go to the local chess club for about three hours one night per week.

I would point out that former World Champion, Mikhail Botvinnik, was a big proponent of studying a lot, and only then, playing. Unfortunately, you can still have too much of a good thing, and I believe his rust showed itself when he lost to Tal in 1960.

P.S. I also think it is fantastic that you spend so much time studying the endgame. I read Ruben Fine's "Basic Chess Endings" cover to cover as an 1100 player, and to this day, it has still influenced my endgame play. The great thing about endgame work is that not much of it ever changes, and thus, it stays with you for a lifetime.


When should you trade off a piece that's defended by two pawns? In some openings, i.e. the Stonewall Attack / Maroczy Bind, the opponent gets an iron grip over a particular square (e5 / d5) by controlling it with two pawns, and they can stick a knight there. People are often very reluctant to trade this knight off, even if it's a very powerful piece that controls a lot of squares in the opponent's territory. In concrete terms, why would trading off for the knight (via capturing on e5 / d5) generally be bad for Black?

Then only strategically relevant reason, that could reasonably be attached to the concept you presented, is in my opionion, that the subsequent change of the pawn structure is unfavourable for the defender. Reasons would vary wildly with the concrete pawn structure. E.g.:

In the maroczy structure white may play Nd5 after preparation and if
black captures the knight, white can capture with the e-pawn and make
the e7 pawn backwards. Or white captures with the c-pawn, opening the
c-file because he suddenly can invade over it.

In the stonewall structure black plays often Ne4 and if white would
take, black would normally recapture with the f-pawn, having a half open
f-file and driving a knight on f3 away. This may lead to an attack or
if not that could force white to take prophylactic measures with f3,
leading possibly to simplifications. Hence white often avoids the
exchange altogether and prepares to kick the knight with f3 and a
further e4.

If white has an isolani on d4, he often play Ne5 or even Nc5. If the
knight is taken on c5, this leads to a passer. If the knight is taken
on e5, white strenghten his pawns and again may become attacking
chances.

Your questions makes absolutely sense to me, but if you want to study chess seriously you can only answer it in on a case by case basis. Stockfish is your friend.
Old FM Roese at your service (https://lichess.org/@/fiskaren)


With a pawn rush, should I take the knight? I was just playing the computer, and it always starts with the knight on b1, moves out his other knight, and then plays his pawn. At this point, should I take his knight with my pawn, or do something else?

[fen "rnbqkbnr/ppp1pppp/8/8/3pP3/2N2N2/PPPP1PPP/R1BQKB1R b KQkq - 0 1"]

Take the c3 knight. Since white has developed only one piece, he can't punish you.  If he takes back with the d pawn, trade queens. Now he can't castle.  Then you develop, move your rooks to the center, and push him off the back of the board.


Why is flagging considered a win? Let's say I totally dominate my opponent, but simply run out of time, then I lose the game right?
But doesn't it make more sense to be given 51% of the rating adjustment (not 50/50 as for a draw).
The criteria would be simple, that is if a user is in a completely winning position by stockfish evaluation (mate in X) or they are up 5+ material points.
I feel like losing rating when you dominate a GM who is rated 500 points higher than you in a 1+0 bullet game just because they moved very fast (and randomly) at the end is a bit unfair. Is there a historical reasoning for not applying such rules?

I feel like you somewhat misunderstand the concept of a time control. The clock is a part of the game. If you are up a piece in a complicated position with five seconds left on the clock that may well be a losing position for you. Sure, the engine may show you +4, but the clock is an important part, especially in blitz.
Importantly, if you spent all your time getting a good position while the opponent played quickly to conserve their time, then they performed better, because they got to a still tricky position while using less thinking time.
If you don't like this flagging mechanic (I for one do not), increment exists for a reason. There is still some time management there, as playing on just the increment means you don't have time to think deeply. However, it allows you to keep playing instead of losing on time. If you play without increment, it is your decision, but then you have to be up to take the consequences.


Strange(?) opening by computer (beginner level) Below is the beginning of a game I played against the 8 year old Magnus Carlsen (yes, I'm a beginner). I'm white.

My opening moves are similar to that of a Spanish opening (but not quite), but I don't understand black's moves here. As far as I can see, there are only negatives (except the queen is threatening b2 if the white bishop is moved). Does this opening have any pros? The reason why I'm asking is that I've noticed that "Magnus" often plays moves that are good if played against a worse player, but rarely moves that are just plain bad (except some major blunders). I win probably 75% of the time against 8 year old Magnus, thus we're almost at the same level.

As far as I know, the most important principle during the first phase of the game is:

Control the center
Activate the pieces
Perform a castling move

My question is: Does black's opening here have any advantages against a beginner or is it simply bad? Is black just "hoping" white will forget about the queen and move the bishop (or some other blunder I'm not seeing)? Am I doing something bad in this opening? What would a be a good next move for white?

[FEN ""]
1. e4 e6 2. Bc4 c5 3. d3 Nh6 4. Nc3 Be7 5. Nf3 Qb6 6. O-O a5

Well, to be honest, it's not a very good opening by either of the players.
While you haven't made any real mistakes, there were chances for black to seize the initiative.

In The French defence, you hardly see black taking the initiative. Black always hopes to sit tightly and looks for counter attack, usually on the queenside. i am not a huge fan of your move (2.Bc4)(Better was 2.d4). The bishop has no future on c4. Well, yes it controls the d5 square but Black could simply have moved (3..d5) instead of that horrible (3..Nh6) and your bishop would have moved twice in the opening 5 moves. Not a good sign. Black's opening here is almost terrible. White gains a substantial advantage and with logical play should win this game without much trouble.

A good move at this stage would be 7.Bxh6 which doubles up black's pawn on the h file and a future Qc1 would mean that the pawn would always be upon attack by enemy forces.


Which openings lead to unbalanced endgames? Some openings often lead to "unbalanced" endgames, where both white and black have their advantages and disadvantages.

For instance, in the Berlin endgame, white has a lead in development and a better pawn structure, while black has the bishop pair.

Are there other openings in which one of the (main) lines results in an unbalanced endgame?

First note that it is impossible to force your opponent into an endgame - chess doesn't work like that. Second, strategically the endgame may be one of the better choices for the opponent eg in the Berlin Defence the consensus on White best option is between the Berlin endgame and the Anti Berlin 4.d3, or equally it may not be, which doesn't mean you can't play it anyway if you like endgames. For examples of opening ideas that lead to unbalanced endgames see the games of Kramnik for example

Kramnik-Timman Wijk aan Zee 1999.

  [StartPly "7"]
  [FEN ""]
  [Event "Wijk aan Zee"]
  [White "Vladimir Kramnik"]
  [Black "Jan Timman"]

1.Nf3 c5 2.c4 Nf6 3. Nc3 Nc6 4.g3 d5 5.d4 cxd4 6.Nxd4 dxc4 7.Nxc6  Qxd1+ 8.Nxd1 bxc6

Kramnik-Van Wely Wijk aan Zee 2001

  [StartPly "7"]
  [FEN ""]
  [Event "Wijk aan Zee"]
  [White "Vladimir Kramnik"]
  [Black "Loek Van Wely"]

1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.cxd5 Nxd5 6.e4 Nxc3
7.bxc3 c5 8.Be3 Qa5 9.Qd2 Nc6 10.Rc1 cxd4 11.cxd4 Qxd2+
12.Kxd2

Kramnik-Tomashevsky Tal Memorial 2012

  [StartPly "7"]
  [FEN ""]
  [Event "Tal Memorial"]
  [White "Vladimir Kramnik"]
  [Black "Evgeny Tomashevsky"]

1.Nf3 d5 2. d4 Nf6 3. c4 c6 4. Nc3 a6 5. e3 e6 6. Bd3 dxc4 7. Bxc4 c5 8. O-O b5 9. Be2 Bb7 10. dxc5 Qxd1 11. Rxd1

All of which won by White. These games are main lines - at least the last two are. I'm not too sure about the English opening in the first game.


How many games can be stored in Chess.com with a free account? I have an account on chess.com, which is a free account. It has been storing all games I played. Is there a limit to this number of saved games? Also, can I delete a game from chess.com? I can't see the option.

I believe the answer is as @double-beep said it. You cannot permanently delete a game from chess.com's archive, and I do not believe there is a way to make it so that you cannot see it. There are, however, a few limited filtering options so you can filter your games, but other than that you cannot delete a game. Also, there are an unlimited amount of games stored on chess, com's database. Anyone can see your games (not the ones played against the computer however), and you can see anyone else's.


Which countries have (or had) chess as a compulsory component of their national curricula? The only country I know of that definitely has chess as a compulsory subject on its national curriculum is Armenia. Are there any others? I think Paraguay may be one.
Please take "national curriculum" to mean the curriculum that is legally obligatory to be taught in all state schools. Thus England and Wales have a national curriculum, even though there is no obligation for it to be taught either in private schools (attended by about 7% of children) or by home educators.
Quite a bit of chess is taught in Danish, Swedish, and Hungarian schools, but as far as I am aware (and I may be wrong) it is not actually a compulsory subject in any of those countries. I thought it used to be a compulsory subject in the USSR but couldn't find confirmation.

In this article in the Majorca Daily Bulletin (2015), the Spanish parliament is described as having unanimously passed a resolution that year to allow regional governments to introduce chess as a compulsory or optional subject in schools. The resolution is similarly described as "non-binding" in the Financial Times.
The first-mentioned article further states that

Armenia became the first country to apply the policy nationwide in
2011. Mexico followed in 2014, as well as parts of China, India and Germany.

The word "parts" here implies that chess is not a compulsory part of the national curriculum in those countries as defined in the question. I have not yet found a fully reliable source for the case of Mexico. So far the only certain case I have identified is Armenia.
A report on the international conference on chess in schools held in Armenia in 2014 quotes FIDE's then president Kirsan Ilyumzhinov as follows:

Recently I was in Mexico. They showed me their national school
curricula [sic] and said that they were going to follow Armenia’s example
and make chess a compulsory subject in schools. The same is true for
Paraguay, Mongolia and Thailand.

Regarding Thailand, I wonder which game is being referred to. International chess is much less played in that country than makruk, also known as Thai chess.


Failing to understand how to start Popeye I am trying to run the chess solving program Popeye, but I am failing to understand how to start the program on Windows.
There is an English guide, and this is all of what is tells you to do:

Starting popeye:
Change the name of your preferred executable to py.exe
To operate it from the terminal:                py
To solve problems recorded in file XX:          py XX

I'm basically illiterate when it comes to code. Can anyone explain how to start Popeye?

For those interested, you can download the exe from https://sourceforge.net/projects/popeye-chess/

There's no reason to alter the name of the executable.
You have to enter command prompt.  On windows this is done by running cmd.exe, or you can use a dos emulator.
When you're in the folder which contains the popeye.exe file, you can start the program by typing popeye.  However, the program is "dumb" and you need to provide more parameters.  The first parameter is the file which contains the puzzle(s).  There are three other parameters, but they're not needed.

For example, the command "popeye puzzle.pgn" starts the popeye program and tells it to solve the puzzles in the puzzle.pgn file.  The program should produce a generic file with the answer(s) and misc. info about what the program did.

There is another method, but that is more restrictive and not really worth mentioning.

This is the method on a Windows OS.  For Linux, Apple, or other OS the procedure is slightly different, but users of these OSes normally are already familiar with these methods.


How can I analyze and annotate multiple (500) games with stockfish? I want to analyze multiple games in one batch with Stockfish. Apart from Scid I do not know any other tool which will do it faster or better. What are som alternatives to Scid with better performance or annotation quality in mind?

Scid allows me to set time or depth (not both at together), put score, put variation, multiple lines analysis.

If you are using Android, Analyze This (Free) is the way to go, just use the 'Auto Analysis' feature.
If you are using windows, Arena Chess is the way to go (you need to install Stockfish, and load the games in a single PGN, and turn on Auto Analysis ...)

Hope this helped, ~CSS


Why doesn't the black bishop just capture the white knight? In a game of mine, the below position emerged.

[FEN "r1bqkb1r/2pp1ppp/p1p2n2/4N3/4P3/2N5/PPPP1PPP/R1BQK2R b KQkq - 0 1"]

It is Black to move. The computer suggests the move 6... Bd4, and then it suggests 7. O-O for White. Why doesn't the black bishop just take the white knight on e5?

Black could take the knight on e5, but then after d4 the bishop doesn't have any good squares. If he tries to retreat to d6, knight and bishop will be forked with e5. In the end white will have better development and better central control, it definitely looks like a ready-made attacking position for white.

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 bxc6 5.Nxe5 Nf6 6.Nc3 Bc5 7.a3 Bd4
8.O-O Bxe5 9.d4 Bd6 10.e5


Looking for an opening line: a rook vs 5 pawns I remember seeing somewhere an opening line, where one side gets rook and the other one 5 pawns, it was pretty sharp. I also remember that it's now considered dubious, because one of the sides was proven to be much better. Unfortunately I don't remember which side was which and also the parent opening or the starting moves. Does this line come to mind to someone? It would be greatly appreciated.

Is it this line in the Advance Caro-Kann of which you are thinking?

[FEN ""]
1. e4 c6 2. d4 d5 3. e5 Bf5 4. Nc3 e6
5. g4 Bg6 6. Nge2 c5 7. h4 cxd4 8. Nxd4 h5
9. f4 hxg4 10. Bb5+ Nd7 11. f5 Rxh4 12. Rf1 exf5
13. e6 fxe6 14. Nxe6 Qe7 15. Qe2 Rh2 16. Nc7+ Kd8
17. Qxe7+ Bxe7 18. Bf4 Rxc2 19. Nxa8 Bh4+ 20. Kd1 Rxb2


Is there an aggresive opening for black if white does not accept the Traxler's counterattack? I want to play sharp, complicated Traxler games in bullet. To do this, I must play the Two Knights Defence. The problem is that rarely people go for the Fried Liver, and usually I play the Four Knights Italian or the Giuoco Piano opening.
[FEN "r1bqkb1r/pppp1ppp/2n2n2/4p3/2B1P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4"]

1. Nc3

or
[FEN "r1bqkb1r/pppp1ppp/2n2n2/4p3/2B1P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4"]

1. c3

or
[FEN "r1bqkb1r/pppp1ppp/2n2n2/4p3/2B1P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4"]

1. d3

Is there a gambit or an aggressive opening/response that could complicate the game from this position into an attacking aggressive battle for Black?
NOTE: I don't expect the opening to be any good

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

1. Ng5

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


In Sicilian Defense with pawn structure as in Scheveningen, what should black do when playing d5 does not look so good? As black, I always play the Sicilian against e4. I personally like the Scheveningen system but to avoid the Keres Attack, I play a6 before e6:

[FEN ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6

In that sense, the opening can also be named as Najdorf variation.

But I generally avoid playing ...e5 and prefer ...e6. I avoid ...e5 because I feel like playing ...e5 weakens the d5 square.

My desired set up is to have:

Bishops on b7 and e7
Knights on f6 and d7 (or c6)
Pawns on a6, b5, e6, d6
Queen on c7 (b6 or sometimes a5)

My general plan is to play d5 to open up the game for my white bishop at b7.

Now I have 2 questions:

Sometimes (especially in closed Sicilian games) against black's ...d5 white can move their pawn to e5 and so creates a pressure on my king side. In those cases I have the tendency not to play ...d5 but then my white bishop can get stuck so becomes a bad bishop. Should I allow e5 with ...d5 and do something after e5 or should I think doing a move different from ...d5?
Secondly, sometimes white pushes their pawn to c4 to block my ...d5. What could be a good strategy for black after c4?

PS. I generally prefer open Sicilian games to closed Sicilian games with maybe one exception. The exception is the variant where both sides make fianchettos on the g-file (like English opening with sides reversed) where the black has pawns on g6-e6-d6, black bishop on g7, knights on e7 and c6.

Then my strategy is to play Nd4 in order to exchange knights, making a queen side pawn rush by putting my rook to b8, and defending a possible g4 by moving my pawn to f5.

Can I apply that kind of play/strategy against white where white does not make a fianchetto with his white bishop where the game is a closed Sicilian game, (e.g. 1 e4 c5 2 c3... ) to overcome the problems that I described above.

It is generally true that, especially in the Najdorf variation, Black does not get to play ...d5 at any point early in the opening: if they do they have basically solved all the opening problems and acquired an equal if not superior position. Conversely, White's plan is to get a grip on d5 and make it the whole point of the opening, very often playing a set-up with "good Knight versus bad Bishop" (there is a good lecture with examples of the Saint Louis Chess Club here).

However, in the standard set-ups of the Najdorf variation (especially against the English attach 6.Be3 or the classical line with 6.Be2) Black plays 6...e5 themselves to avoid White from doing so (unless White plays f4 and then e5, but they have to spend two more tempi to do so) and to get their fair share of the centre. Black's bishop if often deployed in e6 and not in b7 to avoid Bc4.

A good example of this approach is the game Carlsen vs So (Sinquefield Cup (2015)).

  Secondly, sometimes white pushes their pawn to c4 to block my ...d5. What could be a good strategy for black after c4?

If White plays the standard open Sicilian set-up with 5. Nc3 then they cannot play c4 easily; Black will play ...b5 in most of the Najdorf set-ups (also allocating a Knight in c4 if allowed). Therefore the general rule is to avoid White to play c4 rather than worrying after c4 was played. If otherwise White plays an early c4 (Maróczy variation) then this is a completely different line to be analysed and does not fall in the scope of the Najdord (or Scheveningen) variation.

As a general rule, by playing the Najdorf variation, Black allows d5 to be weak, gaining back their fair share of the centre with ...e5 and counterplay on the Queen's side with ...b5 sooner or later. Moreover Black will always try to preserve their Knight on f6 and if possible play Nbd7-Nb6 and Be6 to have three pieces looking at d5. If White really wants to use that square they must do so at the cost of many tempi and converging all of their pieces there, which leaves room for counterplay meanwhile.


Bela Berger and Blindfold Chess: What do players "see" on the board? I was looking at the interesting career of Bela Berger. On this oral history site, Bela Berger talks in an interview.

Here is a quote from the site:

  "Berger, international chess master, speaks about learning to play chess as a child in Hungary; becoming a professional chess player; coming to Australia in 1957; becoming an international master in 1963; playing in Philippines, 1967; correspondence, blitz and blindfold chess; preparing for tournaments; personality of chess players; and the future of chess."

I was particularly interested in his comments about blindfold chess where he says he did not see the board and pieces as such, but experienced them as "pulsating energies".

I had previously heard comments from Ivanchuk along similar lines. Not very enlightening for me!

Berger comments that he could play as many as 10 games at a time blindfolded.

Could  anyone who experience with,  or knowledge of, such feats tell me what blindfold players "see" on the board?

That's pretty much what I "see".  I don't have a mental picture of pieces, I have a "feel" for their mobility.
One of the interesting thing about blindfold players is that they each have their own way of seeing the board.


Endgame problem: How to avoid stalemate and win? I'm stuck on this problem a friend shared with me recently, with barely any pieces left and apparently white is able to force a win but I've been hitting a wall with everything I've tried so far, as everything seems to immediately lead to stalemate...! Here's the diagram of the problem, with white to move and win.

This problem was created by Josef Prokop, and published in Prager Presse in 1924.

 [title "White to move and win"]
 [fen "6k1/6P1/5BP1/p7/8/K7/p7/8 w - - 0 1"]

I know that if I entered this position into an engine I'd probably get the answer immediately, but to be honest as opposed to just seeing the answer, I'm more interested in how one should approach or reason about such problems in order to systematically get closer to finding the solution. So I would appreciate it if someone could flesh out how they approached the problem and step by step got to the solution, that would be incredibly helpful.

It's quite a fun problem to think about, before getting to the
calculation of long variations, try to first spot the key idea needed to crack the problem.

Here are the first observations that come to my mind which eventually
led me to spot the solution, let's break them down step by step:

a) With our bishop eyeing g7 and our doubled pawn formation on g6-g7, black will draw by stalemate as soon as they run out of pawn moves on the a file.
b) With a) in mind, try some basic moves to develop a feel for the position and nuances in terms of timing. So let's attempt to see through some of our king move options: 1.Ka4 is no good as it will end immediately in a draw after 2...a1=Q+ 3.Bxa1, similarly with 1.Kb2 a1=Q+ 2.Kxa1 a4 and the draw is trivial.
c) Count black's remaining moves: in principle there are a total of 5 pawn moves, then it's a stalemate unless we give the black king on g8 a legal move.
d) To ensure the latter, the only way is clearly to let the g7 pawn fall, as g6 cannot move anyway.
e) But how to give away the g7 pawn, while i) our bishop still eyes the promotion square (a1), and ii) afterwards not leave hanging our 2nd and only remaining pawn on g6 which is a light square pawn!
f) observations in e) basically tell us that we cannot leave the a1-h8 diagonal with our bishop or else black promotes. So in order to leave g7 unprotected, our only option is to blind the bishop by blocking the long diagonal with the king!
g) Assuming we leave our bishop on a1, then there are various options for blinding the bishop, for instance getting the king to c3 or d4 or e5, ... which is the right one?
h) We can resolve that by remembering our observation e, ii), namely that after black takes on g7 we need to be in time to protect g6, that means in the very next ply! Therefore, our only option is to block the bishop's sight via e5, let black take, and defend g6 immediately with Kf5, right on time. In fact Kf5 will unavoidably be with check as our bishop is still on the long diagonal! Once g7 is removed and g6 is defended, black has spare king moves and there are no threats of stalemate anymore.

Summary of our discovered idea:

Now it simply remains to execute our plan correctly, which means a bit of concrete assessment of the position in order to find the right move order:

We know we want our bishop somewhere between a1-d4, so let's try the immediate 1.Ba1: 2...a4 and black draws immediately. All other bishop moves lead to the same situation after 2...a1=Q forcing Bxa1.
Let's not waste tempi at start with the bishop since it'll be naturally drawn to a1 anyhow as we let black promote. Instead, let's use all our tempi to get our king to d5 as fast as possible and prepare our Ke5-Kf5 maneuver.

Solution:

   So let's try: 1. Kb3 a4+ 2. Kc4 a3 3. Kd5 a1=Q 4. Bxa1 a2 5. Ke5 Kxg7 6. Kf5+ kg8 the difficult bit is done! Now we just have to shoulder away the king from the promotion square (g8). 7. Ke6 Kf8 8. g7+ Kg8 9. Ke7 Kh7 10. Kf7 and the rest is trivial.

I really recommend to either go through the above discussions without using an analysis board to try out moves, or to try and solve it on your own with mental calculations only, considering our observations a to h. As there are only few pieces in this problem, it can make for a very useful exercise of concentration and calculation.

Animated solution:


About how to win a pawn by applying pressure-Looking for examples Is there any easy way to know you can win a pawn just by applying pressure on the opening? So, if you guys can help me with examples of winning pawns just by applying pressure on each phase, opening, middle game and endgame, I would be very grateful. Also, when to apply pressure on the endgame?

Thanks for the attention.

Edit: Sorry for writing mistakes, it is really hard to write on the phone.

I am sorry to say that the answer is "no", there is no "easy way" to apply pressure and win a pawn in the opening, otherwise, at the top level of chess, the game would be won every time. That is what positional chess is about: You gradually improve your position until the opponent can no longer save all of the material.

A theorem of chess is that you must be better to "attack", or even to apply pressure in a specific area of the board, you have to be better in that area. Being better in a specific area of the board, or the whole board, is a result of good positional chess on your part, or bad positional chess by your opponent.

Usually, players do not start getting a good grasp of positional chess until they are about 1800 over the board (not just online).

Probably the easiest way to win pawns is to cram thousands of tactics problems, and get better at those, so when your opponent drops material, then it is easy to see it, and take it.

I am not going to get into a long explanation of positional chess since there are currently 374 other questions about it, and I know that I have discussed it at length before, but I will leave you with one link to a question I answered.


Algorithm for implementing chess rule It's my first question on the chess stack exchange (actually I asked this question to stack overflow but my question was closed 'off topic'), and English is not my first language. So please understand if my explanation is not clear.

I'm a programming novice. I can use some of C (actually I forgot even basics of C), python, IDL just for scientific calculations, or for graphing.

I'm a moderate custom map maker for Starcraft 1. Yes, old fashioned game. Till lately only algorithm I need to make an custom map in Starcraft was trigger, which consists of condition(if~) and action(do~). There was no more complex algorithm like loop or like that.

However, recently there were much advance in the technology of making custom map with the popularization of EUD trigger.

EUD stands for Extended Unit death Trigger. There is an action in Starcraft trigger named 'Set Death'. The point is, you can set the death value of certain unit (of certain player) outside the allowed range. That makes possible to access and change other game data, like unit attack range or unit appearance(though extreme exploitation were limited in Starcraft:Remastered)

And one map maker (and programmer) made a programming language named epScript in which you can program a custom map and that would compile your script into Starcraft triggers and automatically embed them in a map.

And he wrote some lectures about how to use the language and compiler and the example he chose was the Chess. https://github.com/phu54321/euddraft/wiki

So you can play Chess in Starcraft Battlenet. (Well it was possible before when EUD was enabled but it was a result of such a lot of labor.)

However unfortunately he has stopped midway and I have some reasons to believe that for a while he'd not complete his lectures. So I'd like to continue and complete the chess map for two person, and besides, I wanna apply the principle to make a variant of chess, Kriegspiel, which is one of my favorite board game. https://en.wikipedia.org/wiki/Kriegspiel_(chess)

Anyway, before that, I want to make chess (PvP). But as I said, I'm novice in programming, so I'm not accustomed to make algorithms to realize chess mechanism. So like, I'm not sure how to make script for disabling king to go into a checked cell.

Are there some webpages that lists algorithms for chess making , not language-dependent? I don't want AI algorithm for chess.(well after I finish the job, if I have enough time I may invest some time for that to enable PvC. And maybe for Kriegspiel too..?) I just want algorithms to implement chess rules. Thanks.

You're asking code for validating a chess position. There're a lot, tons and tons libraries. However, I don't think there's anything that you can compile for StarCraft. Consider:

Learn chess yourself. Make sure you know the rules well.
There's nothing you can just grab for your project. You'll need to do it yourself. If speed is not important, you could encode the chess board as a 8x8 two-dimensional arrays. Simple programming. Loop throught the arrays for moves, slow but it'll work for sure.
If speed is important, consider bitboard implementation. Please google bitboard for chess.

Some references:

https://github.com/niklasf/python-chess
https://github.com/official-stockfish
https://github.com/jhlywa/chess.js/

and many many more. Decide your programming language. Your question is too broad for us to answer.


Chess database software for variants For regular chess, I use SCID and it works well. It has database searches, position searches, player stats, and a nice compact file format (i.e. not PGN, which is inefficient and big).

Is there any similar software like the SCID software mentioned above, but for chess variants? I've tried Winboard/XBoard (it reads from PGN, so is slow and bulky, plus it has a slightly stunted search).

An example use case: I would like to organise/search/use a database of only antichess or only atomic games. I should be able to do all (or at least some) of the following:

Save/load the database to and from PGN
Save/load the database to and from a more compact format than raw text PGN (compare SCID .s*4 or ChessBase .cb* formats for regular chess)
Search for games by date/player/rating (or more generally by tag)
Play through the games in a GUI (or at least give me a PGN of individual game(s) I view)

Engine support is not a must.

I leave a partial answer for interested parties:

Scidb (Scidb is a Chess Information DataBase) is a chess information database. (Great sentence.)

It supports some variants (3-check, King of the Hill, Anti/Suicide/Giveaway/Losers, and Crazyhouse), as well as 960 starting. It is currently still in development, and is available only for Linux systems at the moment, requiring a build from source. (It might work on Windows with an appropriate environment configured.)

Unfortunately, it doesn't support the variant I'm interested the most in (Atomic) and is limited to Linux (I do run Linux, but would prefer not to grapple with it as mine runs from an external HDD).

Further answers would be appreciated.


Square Free Position [FEN ""]

For the purposes of this question, a “square” is a set of four occupied cells on the chessboard whose centres form a geometric square. The cell may have any orientation. For example: a1,a2,b2,b1 or a2,b3,c2,b1 or a2,b4,d3,c1.
In the starting position, there are 24 squares that are formed by four Black and/or White pieces. Two squares are tilted. If regular moves/captures are played for Black and White, what could be the maximum number of pieces that can remain on the board without four them forming a square?

TL;DR: a solution!
[FEN "rnbq1bn1/p2pp1p1/1p2r1Nk/2p4p/6PN/1BPP1p1P/PP2PP2/R1BQK2R w - - 0 1"]

32 pieces, no squares.
According to OEIS sequence A240443 and this particular pair of examples, 34 is the maximum possible number of square-free points on an 8x8 grid. As long as each file has at least two points in ranks 2-6, this is likely to give us a solution, if we just drop a couple of the points. (I picked two from the more crowded files.)
This is not intended to be optimal in number of moves - it just shows that a capture-free solution is possible, and is a starting-point for the search for the shortest (non-unique) proof game (which we now know lies somewhere between 4.5 & 7.5 moves).
The rest of this post gives more details.
Generalization to abstract math problem
Overall, I make it 336 possible “squares” on the chessboard, of which 140 are  non-tilted and 196 tilted. Since about 60% are tilted, avoiding the tilted squares in a general position is the harder challenge, although there were only 2 tilted squares to avoid in the game array.
Following an exploration into positions where ranks 3-6 were empty, I think the best general approach may be to forget about the chess for a while. We've got 64 nodes, and 336 "quartets", each of 4 nodes. What's the smallest subset of 64 which contains a member of each quartet? There is no a priori reason why that smallest subset should be greater than 32. (I.e. we might be able to have more than 32 pieces on a square-free board!) Anyway, after that smallest subset is determined, we can see how we can arrange chess pieces to avoid those squares on the board.
Having got a solution, the next thing might be to determine all maximal arrangements of 32-34 square-free points which allow for 2 pawns/file. (It’s the 34-pointers which are most interesting, although it’s possible that some position with 32 or 33 point might not be extensible to 34, so would be missed in any trawl of 34-pointers.) Can then look at the smallest number of moves to reach positions which have 32 pieces. In such open capture-free positions, it seems very unlikely that a unique proof game exists.
If anyone does get a list of these maximal 32-34 point diagrams, I would be grateful if they can be posted in GitHub. There is some python code in OEIS, I saw.
Bounds for shortest (non-unique) proof games
An earlier reconnaissance to look at homebase positions (i.e. where all surviving units are on their apparent starting squares) proved that a maximum of 23 units can remain on the board. A valid implication for the general problem is that any (non-unique or unique) proof game to a square-free position must have at least 4.5 moves (i.e. White moves at least 5 times). This bound is unlikely to be attainable.
Elsewhere in this thread, there is a solution in 7.5 moves. Any faster solution must therefore have at least 9 units on ranks 1 & 2, and at least 9 units on ranks 7 & 8. This constrains somewhat the search for interesting 32-34-pointers.


What motivated Kasparov's comments on the Anand-Gelfand match? I was watching an interview with Kasparov which occurred before the Anand-Gelfand match was played, and he said:

  "Nobody should be offended, it is just a fact, but it's the first time in a long period of time that a World Championship match, with the official champion and official challenger, doesn't have anything to do with fighting for the title of the strongest chess player on the planet."

Why exactly would he say that?  Was it just because Carlsen was not playing, or are there deeper reasons?

Kasparov's reason for that statement may be no deeper than this:

The current rating list does give a concrete, factual basis for his assessment, though it is certainly something with which others might disagree. Current world #2 Levon Aronian, for one, made a point of contradicting Kasparov:

  "I don’t think [what Kasparov said] is true. The player that made it through a very tough Candidates’ Tournament and the player that has held the title for so long are, by rights, the strongest players in the world."

Ultimately, how one defines the "strongest" players is clearly a subjective matter. As for what underlying personal motivations Kasparov might have for saying what he did, we shouldn't speculate; so if that really is what you're after, then I concur with the current vote to close the question. But if you take the rating list to satisfy the "why" of your question, then it seems OK to me.


ChessBase Nalimov tablebases I'm using Nalimov tablebases with Fritz14 and it basically works. Just one strange problems occurs: The engine doesn't mate because the final mating move isn't sorted correctly. It look like this:

+- (#2) move1
+- (#2) move2
= (0.00) move3
= (0.00) move4
# (#0) move5  (mating move)

I've tried to replace/rename TBAccess.dll several times as mentioned somewhere else, but the programm won't start, just displaying the message "TBAccess.dll seems to be corrupted".

Any ideas? Does it work with older ChessBase products only?

Apparently Fritz 14 is capable of reading the newer Syzygy format tablebases.  Certainly the latest Fritz can.

These tend to take up less space than Nalimov format, which used a simpler compression scheme designed for the benefit of older computers.  For example, the 5-man tablebases take over 7GB in Nalimov format but under 1GB in Syzygy format.

So I suggest trying Syzygy before giving up.


Statistics on how a rating or winning percentage corresponds to the (opening, middle, end) game? Have their been any statistics on how your knowledge on part of the game (opening, middle, end) corresponds to your rating or winning percentage?  For example, I have found that if I play opening moves a good number of moves in, my chances of winning go way up.  I am not sure how the middle game or end game affect this though. If player A was very strong in the opening, but semi-strong in the middle-game and player B was semi-strong in the opening, but very strong in the middle-game, does one player have an advantage?  The same goes for the end-game?  I have heard that the end-game is usually where the game is won.  Do masters of the past and current have any direct correlation with these statistics?

No.  There is a rating system based on wins, losses, and draws, not for proficiency in phases of the game.  How would you quantify that?  Knowing the main line on the MCO for your openings?  People are always finding improvements to main and obscure opening lines.  This is the TN (theoretical novelty) that people search feverishly for.  So what might be sound play in the opening in January may be unsound by August.

Further, I have seen flawless openings and middlegames come to grief because of a tiny blunder in the endgame.  As Tartakower once said, the winner is the player who makes the 2nd to last mistake.  So there is not really an accepted method of tying knowledge of component phases of the game to winning percentage, because there are too many other factors at hand.  If the game 's phases could be defined down to a formula of what is good play in the opening, middle game or ending, computers would always win.  We still have imperfections of shortsightedness and obliging opponents, and time controls, and other distractions.


Which chess app plays regular openings I play chess regularly, about 1600 rated. Sometimes I want to play chess on my phone (Android). The chess app I use, Chess free, is strong enough. However, it does not play regular openings, so when I am preparing for a regular match, it is quite useless.

Does anyone know any good apps that play regular openings and are otherwise also decent overall?

It's kind of a broad question, but I thought it's worth a shot here,

what is regular opening(are you going to study 1.E4 C5 2. Na3 because Magnus Carlsen played it)? and any app that supports opening book (chessbase, arena, chessmaster, etc) will play whatever you set in the book. also if you are 1600 - you should study chess, learn strategy, position evaluation and there will be enough opening information for you how to start game if you just read trough good book of 400-600 chess miniatures - they very well show and emphasize what are bad moves in opening that lead to quick loss and also you will learn what are good moves and approach in the opening. At your level opening is not the problem definitely! (My highest ELO was 2650 and I never studied openings explicitly - I always got them as side effect from the other studies)


Is Nc6 good response to c3 Sicilian? I used it sometimes and when I read about c3 Sicilian I found out that it isn't a good response to c3, why ? It seems like you develope a piece and add pressure on d4. I thought about it as good move.
Thanks in advance.

With 1. e4 c5 2. c3 white is aiming to create a strong center with pawns on e4 and d4 (after capture cxd4 cxd4).

... Nc6 does not prevent white from playing d4 and the knight on c6 might later be kicked away by white playing d5. In any case after 1. e4 c5 2. c3 Nc6 3. d4 cxd4 4. cxd4 white occupies the center and is ready to develop his bishops. Black on the other hand is not fighting much for the center yet and still needs to make space for his bishops..

More principled replies to 2. c3 are 2.... Nf6 or d5 that take advantage of the fact that white cannot develop his knight to c3 anymore.

After 2... d5 3. exd5 Qxd5 black has a centralized queen which is not easy to attack (because c3 is played) and the game might develop into a typical isolated queen pawn game. If white choses to play 2...d5 3. e5, black gets a better version of the advance French, where the bishop on c8 is not blocked by a pawn on e6 yet.

After 2... Nf6 the game typically continues 3. e5 Nd5 where white gets a pawn chain on dark squares similar to the French, but black has an easy game attacking the chain with d6, Nc6.... and developing naturally. The same positions can also result from the Morra gambit.

Another option is to play 2.... e6 which might very well transfer into the French defense (but that's likely not something you are happy with if you are a Sicilian player).


Why the ratings used for different time controls are different? The FIDE assigns a player not one but three different ratings:

For classical games featuring long time controls, that is, 90 minutes for the first 40 moves + 30 minutes for the rest of the game + 30 seconds increment from move one, the players have a standard rating.
For games played with a time control of 15 minutes + 10 seconds increment, the players have a rapid rating.
For games played with a time control of 3 minutes + 2 seconds increment, the players have a blitz rating.

A similar method for rating players is also implemented by many websites like Chess.com and the ICC. Why is this done? Wouldn't it be easier and more efficient to measure the global strength of a player to have only one rating?

This question is based on one that was being closed because of being unclear what it was asking.

Different (though related) skills are involved in standard chess and blitz chess.

The standard rating is the one that really "counts" as far as people's lists of the best chess players goes. So you don't want to contaminate that rating, used for hours-long serious games, with results from 5-minute games. The blitz and rapid ratings were introduced recently so that players' games at those time controls can count for something without affecting their "real" standard rating.


Scotch 4 Knights with 4... d5 [FEN "r1bqkb1r/ppp2ppp/2n2n2/3pp3/3PP3/2N2N2/PPP2PPP/R1BQKB1R w KQkq - 4 5"]

If Black "mirrors" White's move 4. d4 in the Scotch 4 Knights, and White wants to play sharp, aggressive moves, what would be the best move? I know that chess engines like Atockfish, GNU Chess etc. would calculate the next move forWhite as Bb5, but I want to exchange pieces. So what would the strongest capture be here?

According to 365chess.com's opening explorer, 5. exd5 is the best capture, with an 83.3% win rate.


Is it bad form to go for a lengthy but losing endgame that you suspect will be winning on time? In blitz games, I sometimes have to choose between sharper positions that I suspect will put me at some slight positional advantage and positions easily played by my side but difficult for my opponent which, if they play correctly, they should win.

For example, I might have the option to exchange down to a queen versus rook endgame where I have a 1-minute time advantage or go for a rook and bishop versus rook endgame where I have the extra bishop but where I might have to use up a lot of time to get there.  Given that choice it seems to me that holding a rook versus queen endgame is relatively easy if my opponent is under time pressure (assuming the endgame is not easily converted into the Philidor position) but winning the bishop endgame is less certain.

That said, when I start sacrificing material for no real advantage except to temporarily solve my opponent's most recent attack, it seems to me that my opponent is likely to get irritated that I am trying just to win on time.  I'm not sure what the appropriate etiquette is in such situations regarding play, however.

All is fair in love, war, and blitz (at least with regards to winning on time, and short of outright cheating).

In blitz, time is a major factor in the game, and it is fine to try and win on time in any situation.

If you used too much time, and your opponent thinks he can flag you, there is nothing wrong with that. It is part of the game.

I have seen Grandmasters check with a queen right next to the opposing king that can be taken for free to win on time, just because it requires that split second to realize what happened.

P.S. If someone does not like being flagged, they can always play with an increment.


What is the B+N checkmate position that leads to a longest mate? Black is trying to avoid a mating net that forces it into the wrong corner. To build the mating net, the White king should cut the black king off the center first, by controlling the center itself. Black can resist that without getting into a form of a mating net. I thought it might be this position where black has no danger of a mating net and has cut the white king off the center.
[FEN "6BK/5N2/5k2/8/8/8/8/8 w - - 0 1"]

I want to capture the essence of this checkmate without relying on brute force search. Just defining general goals that can be extracted from any position.
I am not asking the technique of mating, just how to express them clearly in a systematic way to a computer.

Using the syzygy tablebases by just putting some B+N position in, and looking for the note that says what the longest one is, we can find that it's
8/8/8/6B1/8/8/4k3/1K5N b - - 0 1

with a DTM (depth to mate, in plies/half moves) of 65.
This is probably due to the discoordination of all of white's pieces


How to create PGN notation with wrong moves in it? I was as chess trainer with some young guys on a tournament, and wrote down some of their games. In nearly every game, there were wrong moves in it: king is in check, but does not move or react; making a move with a pawn more than one square, etc.

The strange thing now is, that I have not found any program (chessbase or other) that allows to write down the notation with wrong moves in it. Is there any program that supports that? I know, they should play only legal moves, but in a rapid chess game (of 7 year old boys), non-legal moves are common.

PGN files are normal text files. You can generate it to somepoint using the software and then save the file, open it in a text editor (notepad, notepad++, ...) and continue editing there.


Piece movement statistics I have wondered about piece movement statistics, for example:

How many times is a piece moved in average (in general, but also per-piece, as I'm guessing the Queen moves more than any specific pawn)?
What is the average maximum number of moves for a specific piece?

I found an interesting page featuring the results of some data mining on a sample of 4,226,520 games, and from which answers to your questions can be extracted, at least for that large sample of games, which is probably reasonably reflective of what happens in general.

According to the numbers there, the average game has a ply count of 57.63 (i.e. total number of moves by both White and Black). So the number of times a single piece is moved is, on average,

57.63 / 32 = 1.8009

The page also lists the total number of moves played in these games by each type of piece of each color, from which we can derive the following per-game figures:

White piece moves
-----------------
P: 7.7708 total moves, .9714 per pawn
N: 5.1677 total moves, 2.5838 per knight
B: 4.6259 total moves, 2.3130 per bishop
R: 4.6985 total moves, 2.3493 per rook
Q: 3.5775
K: 3.1718

Black piece moves
-----------------
P: 7.7998 total moves, .9750 per pawn
N: 5.1576 total moves, 2.5788 per knight
B: 4.3511 total moves, 2.1756 per bishop
R: 4.5364 total moves, 2.2682 per rook
Q: 3.4869
K: 3.2875

These figures ignore the fact that some piece moves will have been made my promoted pieces, but on the whole such moves will be a very small piece of the pie, so these numbers shouldn't be too far off the mark.


How should one resign properly? In some of the tournaments I've been to, there were pretty indecent people (some of whose licenses were revoked).
One of my friends had a terrible incident. At the end of the game, he was dominating and his opponent looked at him, told him that he resigned, they shook hands and reset the pieces. When the referee came, their opponent claimed that they agreed for a draw.
Even though the referees asked the other players, they just said they shook hands and reset the pieces together. Naturally, cameras showed the very same thing. At the end of the day, he was not able to prove the fraud and lost half a point from an already won game.
A similar thing might be observed at the end of Carlsen's defeat against Anand in Dubai. What prevents Carlsen from claiming that they agreed to a draw?
Moreover, unfortunately, these types of frauds do not only occur in local tournaments. For instance, there was the game Tal vs. Adamski where Tal's wife saved the day.
Thus, my question is somewhat two-folded. How should one resign properly, and proceed when the opponent tells that they resign?

In the USA, we have to notate our games. This would likely prevent issues where an opponent claimed a draw fraudulently.

I played tournament chess for years and never knew of a single instance of the sort of fraud and cheating that you mention.  (My point is that I have not had to deal with it so others may have more germane experience.)

EDIT - good observation by @ghotir.  If you agree to a result, write the result, sign the scoresheets, and do not reset the board until this has been done. Even so you both have the scoresheets.  That's how it happens at tournaments.


What are White's main ideas in the exchange variation of the Ruy Lopez? I was wondering what are the main ideas for white in the exchange variation, Ruy Lopez opening.

[fen "r1bqkbnr/1pp2ppp/p1p5/4p3/4P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 0 5"]

Thank you.

The main idea, in the exchange variation of the Ruy is "exchange." White will play d4 next, followed by offering the exchange of queens in order to head for an early endgame. That's because he's traded away his light squared bishop, his best attacking piece.

The "classic game" for this opening was played in 1914 between world champion Emmanuel Lasker and future world champion J.R. Capablanca.

In "Chess Fundamentals," Capablanca noted that immediately after the queen exchange, "The reader should note that if all the pieces were exchanged, White would be practically a pawn ahead and therefore have a won game."

White relentlessly strove for the exchange of pieces in the game and won.


Chess positions that are easy for humans but near impossible or confusing for computers I noticed that one student is performing exceptionally well and beyond his level during an online class. I was wondering if there are particular chess positions that I can use during class to find out about such cheating. I would like to know of some positions that are easy and logical for humans but would make engines go crazy.

One way to fool some computers is to give them a fortress and then
offer material to trick them into opening the portcullis.  For example:
[Title "White to draw"]
[FEN "8/8/pr1k4/Pp2rp1p/1Pp1pPpP/2PpP1P1/3P4/3K4 w - - 0 0"]

1. fxe5+?? (1. Ke1)  (1. Kc1)  1... Kxe5 2. axb6 Kd6 0-1

Many computers won't resist the temptation to win RR for PP,
but the resulting pawn ending is lost (Black can play Kb6, a5, a4,
and then break through with f4).  Instead White can just play random
King moves, ignoring any Rook captures, and wait for 50 moves
and there's nothing Black can do about it.


Is there Python code to use the Leela neural network? I am interested in doing some analyses of chess games using the neural network trained for Lc0. To that end I need to be able to turn PGN into the right kind of input vectors and to load and use the neural network trained for Leela chess.

My question is whether there is python code for this somewhere. Especially for the first step, using the neural network shouldn't be a problem.

Alternatively an explanation of how the input vectors are computed might enable me to write it myself.

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

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

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


What are good resources to use to learn how to best use pawns and pawn structures? Pawn structure seems to be one of the key areas that a player needs to know well to be able to have a high rating.

What are the best ways to learn how to best use pawns and pawn structure?

A lot of chess is “what pawn break am I looking for, and how do I accomplish it?” These answer that in depth.

“Complete Chess Strategy” volumes 1,2 and 3 by Ludek Pachman. (This teaches about many basic plans, and what you are striving for with your pieces and pawns, especially. This made a light go off in my head, and THIS is what made me a master.)
“Pawn Structure Chess” by Andy Soltis. (This extends the above to specific opening structures.)
“Chess Structures: A Grandmaster Guide” by Mauricio Flores Rios (This is an extension of “Pawn Structure Chess”, and is deeper, and covers more structures. It is outstanding especially if you have already covered “Complete Chess Strategy”.)

I have not read this yet, but another book that seems to be right up that alley by a renowned player is "Winning Chess Middlegames: An Essential Guide to Pawn Structures" by GM Ivan Sokolov (2706 peak rating and #16 in the world in 2004).

Of course, the original book in this genre was "Pawn Power" by Hans Kmoch, but he used a lot of funky terms.


What is the average length of a game of chess with only random moves? The famous Shannon number, 10^120, an estimated lower bound on the number of possible chess games, is based on the assumption that a typical game lasts 40 moves.

In games between skilled human players, this average game length seems to be about right (see this question), but if we want to count all possible chess games, then we also have to include the vast majority of games where the moves don't have any purpose or sense whatsoever. Such a game with random moves would surely be likely to last more than 40 moves?

So what is the average game length of a random game? This should be easy enough to simulate on a computer.

I reran the script from the answer GloriaVictis linked.

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


If the Sicilian is so strong, why do people still play e4 in competitions? 1.d4 is a statistically more successful opening for white due to the high success rate of the Sicilian defence against 1.e4

I understand it's fun to play different openings, but at the highest level, why risk playing a statistically weaker move?

How much statistical difference is there? Is it really statistically significant?

Do these statistics take account of only GM games, so are they biased or not?

And do you know that not every player is a Sicilian expert? Actually, it's quite tough to be a Sicilian expert.

  Had I not played the Sicilian with Black I could have saved myself the trouble of studying for more than 20 years all the more popular lines of this opening, which comprise probably more than 25 percent of all published opening theory! - Bent Larsen

After e4, there are a lot of responses you can get; it's not automatically Sicilian. As far as I remember after e4 there is approx. %25 chance you get into the Sicilian.

Even if you get into the Sicilian, there are Anti-Sicilian variations and gambits where White is very comfortable. My favourite is the Smith-Morra gambit.

And even if you get into standard Sicilian variations, White is absolutely OK.

Also if you only care raw statistics, there are some awkward moves which have more than %60 win rates.

Conclusion: the Sicilian Defense is not a ticket to win.


Is it possible to game my online chess rating? When playing online chess, it is often possible to influence the order in which games are finished, either by choosing when to resign, or by intentionally playing as slowly as possible.

Once the outcome of a game is pretty clear, is it possible to "game" the rating system by manipulating the order in which games are finished? For example, if I'm currently losing against a low-rated player and winning against a high-rated one, will it make a difference if I first resign against the low-rated player, or wait until I win against the high-rated one?

A while ago you asked a related question. According to the answer you should probably resign games sorted by rating loss. If your rating drops quickly at the beginning, the subsequent losses should be smaller and the gains bigger.
At Gameknot this effect might be weaker because in that case they not always use the rating from the end of the game. But the safe bet is to always resign in sorted order. And there is another conclusion: You should start your new games at the moment, when you rating is lowest.


Why white retreats the knight at the beginning of the game? This is one variation from Bird's Opening:

f4 e5 2. e4 exf4 3. Nf3 d6 4. d4 g5 5. h4 g4

  [FEN "rnbqkbnr/ppp2p1p/3p4/8/3PPppP/5N2/PPP3P1/RNBQKB1R w KQkq - 0 6"]

The most popular move is Ng1 instead of Ng5. Am wondering why retreating the knight is a good idea. Doesn't this move violate some opening principles in developing your pieces? After white retreats the knight, he has only three pawns developed while black can continue with Bh6, developing the bishop whilst supporting the f4 pawn.

The opening is called King's Gambit and is usually reached with a slightly different move order after 1.e4 e5 2.f4....

It used to be popular a long time ago (100+ years) for its potential of wild games, but is probably slightly incorrect and not a good choice if your opponent knows what to do.

Arguing with general opening principals is not really meaningful here, because the opening is very concrete/tactical.

After your suggested Ng5 for instance you'd have to be prepared for f6 after which the knight is attacked and will be lost due to lack of retreating squares. White would get 2 pawns for the knight, but that won't be enough.

Retreating the knight, while not ideal, is a better option.


Where can I watch live commentary and live matches between Grandmasters? I want to watch live matches between GMs. In India here are no TV channels that provide me these matches.

Chess24 has a lot of live transmissions of tournaments. Often even with live commentary and always with computer evaluations (though those can be turned off).


What is the longest non-cyclic forced sequence of moves? I am looking for positions from where every move is forced up to a certain depth. If the original position (or one in between) occurs again, the sequence is finished there.

9 moves
In the linked thread (not quite a duplicate), a valid answer is posed to this question:

You mean like this?

[Title "Vilhelm Röpke, Skakbladet 1942, Mate In 6"]
[FEN "K1k5/P1Pp4/1p1P4/8/p7/P2P4/8/8 w - - 0 1"]

White mates in 6.

I guess that's 9 consecutive forced moves. It would be eleven except for black's choice of promotion piece on his fifth move. I don't know if it's a record, and I don't know who composed this classic chess problem.


If both players simultaneously resign, what is the result of the game? Let's say a tournament decides to have special consolation prizes for players who finish in the 20th, 30th, 40th, and 50th positions. It does this to give incentive to players to keep playing all rounds even if they don't have a chance of finishing in the top 10, who would get the normal prizes.

Now suppose player X playing the last round calculates that if he now resigns, he finishes exactly 20th, so he resigns. However, his opponent Y calculates that if he resigns now, he finishes 30th. Both players have incentive to resign. So as soon as X resigns, Y resigns as well.

So what is the result of the game?

In such a hypothetical situation, I wouldn't be surprised if both players lose and will be eliminated from the tournament's results, thereby not qualifying for the consolation prize. It's entirely possible to classify their behaviour as unsportsmanlike and discrediting the game of chess, which is against the FIDE Code of Ethics.

  2.2.10
  In addition, disciplinary action in accordance with this Code of Ethics will be taken in cases of occurrences which cause the game of chess, FIDE or its federations to appear in an unjustifiable unfavorable light and in this way damage its reputation.


Can you improve in chess subconsciously, over time? Years ago, I was a bullet-chess (1 min. games) addict. I played daily and often. Then I stopped for about 4 years (and played off-and-on). My rating was mediocre - around 1400 on Yahoo Chess.

Recently I started again, 3/0 games and blitz games. I noticed that I play better overall, but I can't pinpoint what it is - I just know I can see combinations better. I wonder about this a lot, because as I age I should be slightly slower mentally (I'm close to 30).

First, saying you "feel" like you're better is does not appear to be very scientific, so keep that in mind when attempting to understand the events you're describing.

Also, I don't believe what you're experiencing is related to the subconscious development of your understanding of chess, but you experiencing the difference between cramming knowledge into your brain, and what's called the "Spacing Effect".

(Let me know if this answer addresses your questions, or if there's something I'm missing.)


"Parity" of "insuficient mating material" What is sufficient mating material?

I found this question and must pose my own as a response.

I you have a chess computer on easy (or the Kasparov Team Mate - anyone who has played one will know the "why did it do that?" -> "Oh, if we don't trade knights, then bishops, then our other bishops and a rook, I'll lose!" it loves to swap and the above has actually happened) you will probably end up with most of the pieces off the board.

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

The algebra of this behavior coupled with intuition suggests that if you think of a move as a 2 element tuple (white's move followed by black) that these are from groups with an LCM of their orders of 2. Which is why no number of moves will give a checkmate, thus meeting the 50 move draw at most.

My question is this, what is the algebra behind this? I'm pretty sure it deals with cosets of orbits of board layouts. My Algebra isn't strong enough to analyse this but there is SOMETHING at play.

Secondly, imagine you could "bump" the board, so your knight shifted without anyone noticing one square horizontally. Now it is on a different colour, this should adjust the parity (illegally, albeit) and now you should be able to mate.

Now this raises the question of "if this happens a lot, play to protect the other knight, as it starts on a different colour (thus is the opposite parity), then you should be able to win)" This would make which knight you have left the deciding tool between stalemate (accidentally making it so they cannot move their king (with nothing else left) but not checking him) and checkmate.

Chess is a hobby of mine, I am quite new to the established realm of it, I sort of learned myself from electronic boards (which I still do, I have some strong ones! (Kasparov Turbo s24k, the one after this famously played Kasparov, a GK2000, a GK2200, a Kasparov Cougar (ELO estimated by enthusiasts to be 2100, manufacturer claimed 2250 IIRC) -I say this to try and show I'm not a noob).

I hope somebody can parse what I'm trying to say, I do apologise for the poor quality of this question. I'll try and play an example tonight and edit it in if no one can understand this.

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

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

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

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

1.e7+ Ke8 2.Ke6

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

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

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

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

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

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


Lowenthal-LabourdonnaisSicilian Kalashnikov Variation I have been studying the Kalashnikov Sicilian:

e4 c5
Nf3 Nc6
d4 cxd4
Nxd4 e5 (signaling the Lowenthal variation)
Nb5 d6 (d6 signals the Kalashnikov variation)

I have two books I have been studying that cover variations from this point forward. However, I spend a lot of time analyzing my openings and a line that comes up over and over again is

Bg5!?

The book Neo-Sveshnikov by Silman "covers" this line with one brief note about it on the last two pages of the book. The other book I am studying "Sicilian Kalashnikov" by Jan Pinski, Jacob Aagaard which I really like does not cover this move AT ALL.

Can anyone recommend a resource for me to read about the Bg5 continuation of this line? I find it hard to believe that it can be used somewhat commonly in GM level games and not discussed in any opening books.

This has been one of my main two openings since it became popular in the 1980's again. With strong computers today, they say, and I agree with them, that black is virtually winning after the following line:

  [fen ""]

 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 e5 5.Nb5 d6 6.Bg5 Qxg5 7.Nc7+ Kd8 8.Nxa8 Nf6 {already -2.05 on Stockfish} 9. Nc3 Nd4! 10. h4 {best per four engines} (10. Qd2 Qxd2 11. Kxd2 b6) Qf4 11. g3 (11. Bd3 Be6 {and there is still nothing to stop the roundup of the Na8.}) Qf3 12. Qxf3 Nxf3 13. Kd1 {is given as best, and the Na8 soon falls.}

It is clear that black's development combined with his soon-to-be material advantage (Na8 falls), makes this winning for black, and there really isn't even much counterplay to make it interesting.

The problem earlier is that the Qg5 is very actively posted, e4 is weak, and the move Nc6-d4 is not only keeping the white queen from being active due to c2 being weak, but it blocks white from getting at many critical weak squares like d5, d6, and the d8 square where the black king is.


Suggestions about books to read I am a beginner player and I am studying the game on some classical books: I began with "A primer of chess" by Capablanca. I would like to continue with these 3 books:

"Chess Fundamentals" (Capablanca)
"My System" (Nimzowitsch)
"Hypermodern chess" (Alekhine)

In which order would you suggest to study these books?  Could you also suggest to me something else to study?

Capa's books are very good for your level especially the one you mentioned.
My System is probably too advanced for where you're at. It's a great book but probably better for someone around 1800. Beginners should focus on not making huge tactical mistakes. Positional play like My System teaches you how to plan what to do when you can play a game without making huge mistakes.
I don't know the other one but judging by the title I would say it's way too advanced. You won't be able to understand hypermodern chess until you have a crystal clear understanding of classical centers. Few players below 1800 have any clue what they're doing in the center.
As far what I would recommend-
I really like the book Learn Chess: A Complete Course by C. H. O'D. Alexander. I admit the book can be a little hard to read but it covers every aspect of the game and includes hundreds of tactical puzzles. The chapters on attacking are the best I've seen outside of Vukovic and are targeted towards beginner players.
Silman's Complete Endgame Course: Yes, it's an endgame book but you will learn exactly what you need to know for the level you're at. Endgames are also good for beginners because you break the game down into smaller parts and learn to use the pieces individually.
How to Play Good Opening Moves by Mednis- The book is small but i promise you you can reach 2000 without knowing anything more about the opening than what's in that book. Center, development, king safety. That's all you need to know.
Any tactics book. If you do tactics problems you will get better. Probably the book that will give you the most "bang for your buck" is How to Beat Your Dad at Chess. The tactics are common and the section on facing a strong opponent is good advice.
I'll add one more and that's Rapid Chess Improvement by de la Maza. You can buy the book if you want but the book was based on a couple of articles written by de la maza which are still freely available on the internet (search 400 points in 400 days .pdf etc) Most of the rest of the actual book is testimonials and maybe a little elaboration in some areas. Basically, de la Maza argues that you need to study tactics and develop an effective thinking process to improve from beginner to intermediate. You won't find a strong player anywhere who disagrees with that even if they don't like de la Maza.


Did Spassky stand up and applaude at Fischer after the famous Tartakower game? Is it true that Boris Spassky stood up and openly applauded at Fischer after the sensational round 6 win by Fischer in the 1972 World Championship match? (The QGD Tartakower), as portrayed in the 2014 "Pawn Sacrifice" movie?

Yes.

  The game itself was majestic, by far the best to date. Harry Golombek
  described it as "a masterpiece through and through." Fischer was able
  to create and then remorselessly exploit vulnerable spots in Spassky's
  barricade, prizing his defenses apart before battering him with the
  rooks and queen, and without once leaving his own position at risk.
  Spassky was virtually in zugzwang -- a term referring to an unusual
  position where a player would prefer not to have to move, since all
  possible moves will only make his position worse. Black's resignation
  position was quite pitiful, the king humiliatingly exposed to the
  world, like a naked man caught in the shower after the rest of his
  house has collapsed about him. The packed auditorium rose as one; a
  bemused, crushed Spassky joined in the applause, clapping for his
  opponent in recognition of the artistic creation to which he had
  fallen victim.

Edmonds and Eidinow, Bobby Fischer Goes to War (2003)


Looking for website for organising private tournaments with swiss system? Do you know any website for organising online chess tournaments with swiss pairing method ? I know lichess.org but they don't support it anymore :/

The related question How to organize a chess tournament appears to have several suggestions; I'm not personally familiar with any of them, but most of the links seem to still be active.