Using Stockfish in Commercial Apps Stockfish uses a GPLv3 license, which requires you to release your source code if you use it. This then makes your own code GPLv3. However, chess.com, chessable and decodechess all use Stockfish.
So, how do they use it without releasing their source code? Or, are they taking a risk?
I've read some stuff about pipes, wrappers, running off the server does not count as distribution. Perhaps someone with more knowledge on this can share what they know.

I'm the Technical Lead of Chessable and the exact person who integrated SF on Chessable.
There are no license issues here because web app is not the same work as a Universal Chess Interface (UCI) chess engine.
Technically you do have the code because the whole UI in JavaScript is being sent to your web browser. Check your Google Chrome network tab, you will find all the JS source code there! We are doing client side JS Stockfish integration, so we can't stop you from copying the minified but working JS code. However, we are not going to give you the code like in GitHub format.
Thanks for trying our SF integration!
https://opensource.stackexchange.com/questions/11490/minified-gpl-code-inside-javascript-webapp is incorrect. The answer failed to address the UCI protocol. All communications via the engine is being done by the UCI protocol. The exact same code without any kind of modification can run on any other chess engines following the UCI protocol. Komodo on chess.com is an excellent example.
The engine and rest of the app is not considered a standalone work, which is what GPL is about. It's like Chessbase shipping their GUI and Fat Fritz 2. Did you ask Chessbase for source code of their GUI? The SF engine in JS is not an executable linking to the app. It's actually you who chooses a browser and run the SF. It does that by running web workers like Chessbase on a standard UCI protocol. Stockfish is not a library or derived work, it's an independent piece of code that your own browser runs it.
PS: Any views here are not my employer's and purely mine.


Is there a chess move history app for Mac? I would like to check various positions to see if I have reached them in the past. I play on lichess.org which lets you download your complete game history as a pgn. I was wondering if anyone knew of a program (or maybe site) that runs on Mac OSX that lets you check position history and shows how many times you have reached that position (and maybe shows what moves you played next).
I have ChessBase on Windows but was looking for a Mac alternative.

I believe the Scid vs PC and Xboard would do the job. They can both run on Mac.


Is there a formula that converts a number from 0 to 959 to a corresponding chess960 position? I am looking into a website with starting positions for chess960.

000 BBQNNRKR
001 BQNBNRKR
002 BQNNRBKR
003 BQNNRKRB
004 QBBNNRKR
005 QNBBNRKR
...
959 RKRNNQBB

So there is a table that converts any number from 0 to 959 to a starting position. For example chess960(518) = 'RNBQKBNR' normal starting chess position.

What is this formula? How can I do this without storing all the table?

From Wikipedia:

  White's Chess960 starting array can be derived from its number N (0
  ... 959) as follows:

  a) Divide N by 4, yielding quotient N2 and remainder B1. Place a
  Bishop upon the bright square corresponding to B1 (0=b, 1=d, 2=f,
  3=h).

  b) Divide N2 by 4 again, yielding quotient N3 and remainder B2. Place
  a second Bishop upon the dark square corresponding to B2 (0=a, 1=c,
  2=e, 3=g).

  c) Divide N3 by 6, yielding quotient N4 and remainder Q. Place the
  Queen according to Q, where 0 is the first free square starting from
  a, 1 is the second, etc.

  d) N4 will be a single digit, 0 ... 9. Place the Knights according to
  its value by consulting the following table:

0     N   N   -   -   -
1     N   -   N   -   -
2     N   -   -   N   -
3     N   -   -   -   N
4     -   N   N   -   -
5     -   N   -   N   -
6     -   N   -   -   N
7     -   -   N   N   -
8     -   -   N   -   N
9     -   -   -   N   N

  e) There are three blank squares remaining; place a Rook in each of
  the outer two and the King in the middle one.


Linux: is there any engine that could play your game like Shredder? On Windows, I used Shredder to not only analyze my games, but play the game against me or against itself from any given position.

I used many engines but only found that option in Shredder, maybe I didn't notice that option in other engines.

Now I dumped Windows, and moved to Linux, Xubuntu. While I still could run Shredder on wine, I'd like to know if there's an engine, that runs natively on Linux and that has that option.

I have Pychess and Scid with crafty. I still don't see it, on Windows I tried many engines and didn't see it, is Shredder the only engine that has this option, or am I missing something?

Edit

I would like to know if there's a free alternative to Shredder that has that option. If not, then I'll download Shredder.

Shredder 12 runs natively on Linux.

http://www.shredderchess.com/chess-software/linux.html


How and why were the chess pieces given as "odds" predetermined? For instance, "pawn odds" is really "pawn and move" odds. That is, the odds giver plays Black and removes his KBP.

Why not allow an "intermediate" odds where the odds giver plays white? And why not allow the odds give to choose which pawn to remove?

In the case of knight and rook odds, it is the queen knight or rook that's removed, but why not allow the odds giver to substitute the king's pieces instead?

I would like to challenge the premises in the question:

  Why not allow an "intermediate" odds where the odds giver plays white? ...In the case of knight and rook odds, it is the queen knight or rook that's removed...

Emmanuel Neiman cites the following example in Tune Your Chess Tactics Antenna:

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKB1R w KQkq - 0 1"]
[White "Kennedy"]
[Black "NN"]

  1. e4             e5
  2. Bc4            Nf6
  3. d4             Nxe4
  4. dxe5           Nxf2
  5. O-O            Nxd1
  6. Bxf7+          Ke7
  7. Bg5#            1-0

Admittedly this game is played in the nineteenth century, but it is a counterexample to the premises in the question.

Seeing as handicaps are not in the FIDE rules, then it is for the players to agree as they see fit, and in this example the players agreed that white would be without his kingside knight.


Can't capture queen? I'm new to chess. Just played a game, my king was on d2, opponents queen was on e1, and my rook was on h1. But the program did not allowed me to capture the enemy queen with my rook, it only allowed to move my king to safety.

Why couldn't I capture the queen with my rook?

To illustrate what was discussed in the comments above...

If we can exclude computer bugs, or other problems (there were no other pieces on g1, or f1 were there?), the situation you describe is only possible if:

the last black move was a promotion of a pawn to a queen on e1 (this pawn could have come from e2 or by capture from f2), and...
a black rook or queen was positioned on h2, g2 or f2

One example of such situation:

[FEN "2k5/8/8/8/8/8/3Kp1r1/7R b - - 0 1"]

1... e1=Q+

The technical term for this situation is Double Check and the only response to a double check is a king move as capturing one piece would still leave your king exposed to a check from the other piece.

For the example above, the only legal moves are 2. Kd3 or Kxe1. If the black queen on e1 was protected by another piece (e.g. by a black bishop from g3), the only legal move for white would be 2. Kd3.


Why does Stockfish recommend Kg2 here? When I turn on threat analysis and it gets to a depth of 24, it says Black wants to play Qe7 or Nh7 (after the latter, White's recommended move is again Kg2). I imagine the point of White's move is to prevent something from happening, maybe some attack along the semi-open f-file, but I don't really see any concrete moves for Black that would require White to play Kg2 with such urgency.

I realised as I finished typing up my question that if White wants to trade off the knight for a Bishop (thus retaining the bishop pair, which is good for reasons, probably) White can't just play 3.Ne5 immediately, because after 3...Bxe5 4. Bxe5 Black can play 4...c4!, and now threatens to fork the king and the bishop. For example, you could continue 5. Qxc4 Rc8 6.Qa6 Qc5+, after which White is still better, but then Black has counterplay and active pieces (e.g. Black can play ...R8d8 and have pressure along the d-file, and apparently ...Ng4 is playable as well, but I don't understand that line).


I know every tactical theme pin, fork, weak backrank, deflection, etc.
But upon analyzing this game, couldn't find any.

If you can't recognize a pin (e.g. 9. Bg5) then you don't know what a pin is. Here are 4 tactical themes in the first 20 moves:
9. Bg5 - pin
12. e6 - discovered attack
17. Qe3 - pin
20. ... Qxe6 - self-pin

How can I improve my recognition of tactics?

First you have to learn what they are.

Bg5 pins the knight against the queen. There is no immediate threat, there doesn't have to be, but this move means that the knight can't move without exposing the queen to capture.

There are "hard pins", where a piece is pinned against the king and it would be illegal to move the piece, and "soft pins", like here where moving the pinned piece would expose the piece behind it to capture.


Is this rook sacrifice intended? rnbqk2r/p1pp1pbp/1p2p1pn/4P3/2BP4/5Q2/PPP2PPP/RNB1K1NR w KQkq - 0 1

Is the rook sacrifice intended by the black to trap white's queen or is it just a misplayed move?

In general, it's very hard to trap a queen like that. After Qxa8 Nc6, the white queen can't escape immediately but it's not hard to devise an escape plan; with Bb5 White threatens to exchange the only defender of the a7 pawn, and at the same time winning another pawn on c6. So my conclusion is that Black's last move was a blunder.


What common patterns should I look for in chess? When I started learning, I had lots of games where I lost lots of material through not being familiar with these sneaky attacks. I am talking about these:

There are many more (two minor pieces being attacked by a single pawn, discovered checks that result in attacking important pieces, etc)

I think it will be of great help to study them again and have them freshly in my mind (they often go unperceived, both when spotting them, and stopping them).

What you here call 'patterns' are more commonly called chess tactics. See the Wikipedia article for Chess Tactics for a list with some visualization.

These are the simple patterns. There are more complicated patterns that arise rather less commonly, but these complicated patterns tend to simply be a composite of the 'basic tactics'.

A fine example of a more complicated pattern is the windmill: Wikipedia article for Windmill


Is there a website that supports blind chess? Is there an accessible chess website where I can play chess without seeing anything?

Lichess has an option to play blindfolded if you have an account registered.
You have to activate the Speech Sound effect, in the upper right corner → Sound → Speech.
To enable writing coordinates(e.g. Nxe4) instead of moving pieces you can activate blindfold mode in your game display preferences.
Enjoy your games!
Source


"Brilliant Move" - Chess.com - But Why? I was playing a tournament on Chess.com and received a "Brilliant Move" in the post game analysis. I haven't received this before and was curious of the following.
[FEN ""]

1. d4 d5 2. c4 e6 3. Nf3 c5 4. Nc3 Nc6 5. g3 dxc4 6. e3 Nf6 7. Bd2 a6 8. Ne5 cxd4 9. Nxc6 bxc6 10. exd4 Rb8 11. Bxc4 Rxb2 12. Bb3 Bb4 13. Qc1 Rxd2 14. Qxd2 Ne4 15. Qd3 Bxc3+ 16. Ke2 Qxd4 17. Rhf1 Bxa1 18. f3 Nc3+ 19. Kd2 Nb1+ 20. Rxb1 Qf2+ 21. Kc1 Bf6 22. Ba4 O-O 23. Bxc6 Rd8 24. Rb8 Qc5+ 25. Qc2 Qg1+ 26. Qd1 Qxd1#

What is considered a "Brilliant Move" ?
What about the 12. Bb4 move constitutes it being "Brilliant"

My logic was to maintain pressure , develop the queen towards the center , trade out a rook when I felt like there was no way I was going to be able to keep it back there. I am quite low ranked (very new to chess outside of the odd game with friends) . I don't see how this is considered a brilliant move as it was just placing pressure , buying  little time for future development.

My Thought Process;

Rxb2 - Free Pawn remember hearing about Rooks on the 7th , lets give it a crack

Bb3  - That didn't work out so great, rooks trapped in there, lets hope he moves his black bishop to try and take it so I can keep the attacks up and check him.

Rxd2 - Going to lose the rook to the queen, may as well try and capture a minor piece.

Ne4  - Maintain Pressure on the Queen , can't take my knight without losing his queen, can probably capture his knight put a check in, when in doubt check it out.

Literally nothing about that felt "Brilliant" anyone able to assist with why it was perceived to be good?

Engines are far better at spotting mistakes than at recognizing "brilliancies". You made a move that is much better than all the alternatives which isn't something obvious like a recapture or a fork in one move, so that's probably what the engine identified as "brilliant". Just don't pay too much attention to it and congratulations for this beautiful win!


Can a pawn move to the last row diagonally without a capture? Playing the "Champion" J2ME chess, I noticed that the bot (black) made the move "Pg2-h1=Q." Is this a bug or just a rarely known rule like en passant and castling?

Pawns only go diagonally when they capture. See the section 3.7 of Chess rules.

The software you mention probably has a flaw.


How computers have changed the way humans play chess A few years ago Vishy Anand mentioned in an interview that computers had changed the way humans play chess.  Obviously computers help a lot in opening preparation, but what other concrete examples are there?

Is there a certain opening line or endgame whose evaluation has changed a lot due to computer analysis?
Have new principles or strategies been found thanks to computers?
Are grandmaster specifically training to play computer moves instead of relying on traditional principles?

Computers allowed the creation of endgame tables, which allow the user to know with 100% certainty if a position can be won, and how to do it. Currently all positions containing 7 or fewer pieces are 100% known.  I am unaware of any opening line busted by computers.
Not that I know of, but computers do find answers to some hard questions. So while computers don't change the principles, they can surely change the evaluation of specific positions. For example, it is common for computers to find flaws in pre-computer chess books, even books held in high regard.
No. Grandmasters use computers as a training aid, however.


Why would black resign in this situation? I was playing online with someone I do not know that is considerably better than me. I am still somewhat new and I can't figure out why they would resign after castling. What am I missing?

[fen ""]
1.e4 g6
2.Nf3 Bg7
3.d4 d6
4.Nc3 a6
5.Bf4 Nd7
6.Bc4 e6
7.O-O Ne7
8.Bg5 h6
9.Bxe7 Qxe7
10.Qd3 b6
11.d5 e5
12.g4 Nc5
13.Qe3 Bxg4
14.h3 Bxh3
15.Rfe1 O-O 1-0

White gave up two pawns, the g-pawn and the h-pawn, without any compensation. Black's position is objectively winning. So my guess is that black had some non chess reason to resign the game. If this was a blitz game, then perhaps your opponent got a phone call or had to join the dinner table. From a chess point of view, black would have continued this game.


Method for precise calculation? I'm tired of being stuck on a chesstempo rating 1530-1570 tactics in Blitz for like 5 days I'm "not" improving. Sometimes I  take more than 2 minutes and sometimes I just move on quickly to the next puzzle to satisfy my ego. Is there a perfect way to calculate?

Being stuck at a certain level is not unusual and I would not worry about it.

Since you asked specifically about "precise calculation"...

You should be aware that solving tactics is not only about being able to calculate accruately many moves deep. It is also about recognizing certain patterns / tactical motifs that appear in every puzzle.

Particularly at your level it is much more likely that you fail some puzzles because you are not aware of a motif, rather than missing a defensive option many moves down the line that you did not calculate.

After you solved a puzzle or failed to do so, chesstempo shows you the motifs. Make sure you understand each of these motifs in the solution.


When is a bishop and knight stronger than the rook? Often times, players will trade their rook for the opponent's knight and bishop.

This seems to have a slight advantage materialistically as a rook is worth 5 and a knight and bishop are worth 6 total. But from a strategic view, this seems quite unnecessary as it is very hard to coordinate the knight and bishop together (it takes 33+ moves to checkmate by themselves versus a King) let alone deal with a rook at the same time.

Midgame though, they might have an advantage as with all (or most) of the pieces all over the board, the rook may have trouble navigating through the board. The bishop-knight pair though should be sound since the knight should just jump all over the board. Endgame though, I just don't see how a knight and bishop can overpower a rook.

So my question is, when is a bishop-knight pair generally stronger than a rook?

N+B is generally considered to be superior to R+P, because of their greater coverage of squares and the ability to attack the same point twice rather than once. N+B is drastically better than a lone rook in a normal position.

Except for positions with immediate tactics, the only time I can think of that a rook might be superior is in an endgame with passed pawns for both sides. Rooks excel in such circumstances.


Is it worth it to transition into more open lines when one is used to closed, positional games? I've played the French and Queen's Gambit, which tend to lead to more closed, positional play.  I've played these openings consistently for roughly 25+ years now, with no set opening before then really.  I did try to learn both the Center counter, or Scandinavian, and the Danish early but eventually gave up and played random moves (I was quite young).  After that it was Petrov for a year, then on to closed games.  I'm currently 38 and have been at closed positions now for 25+ years.  By consistent I mean every single game I've played since then.  If it is relevant my USCF is around 1500, with a peak of 1620.

From a strong expert:

Just because I find open games to be more fun, I would suggest playing more open games.  Also a variety of openings will expand your knowledge.  (Looking at your tournament history, you may already have enough knowledge.)  Just like you don't quit smoking in one day, don't switch to overly aggressive opening.  Try the Scotch, Vienna, or Giuoco Piano.  These openings requires the learning of more opening traps, but they should improve your quality of play.

Assuming that you have the time to invest in studying an opening, learn the common positions and plans.  If after trying this style you feel uncomfortable, go back to playing the closed/positional games.  If the game is not fun, it is not worth playing.

When I reached expert level, I switched to a more positional game because I thought this is what was supposed to happen.  I lost many games because I hid my talent.

Some GM said that he switched to d4 because he got lazy as he got old.  Anna Zatonskih said that with d4, White can make more mistakes before losing the game.  You could be hanging on to the safety of known avenues.


What do D and +-- mean in chess annotation? When using Stockfish to annotate some of my games, I will often get the symbols D and +--,  which I can't find definitions for. I think that +- means “decisive advantage” for White, and that +-- might mean “very decisive.” As for D next to a move I am at a loss.

"D" means see diagram. "+/-" means white is better, but not much better.


Time Control for Bullet, Blitz and Standard Does anyone know the function which dictates which three of these time-control categories any particular game would fall under?  For example, I know that a 3 0 is the quickest blitz game that can be played but I would be unsure whether or not a 2 3 (2 minutes on each persons clock with 3 second increments added) would be blitz or bullet.  I'm assuming there is a fairly simplistic formula I could plug these metrics into for a definitive answer but I have yet to stumble upon it.

Thanks ^_^

There is no such globally accepted formula. Time controls are defined only by their formal definitions (as unhelpful as that sounds). Any further descriptive language, like "blitz" or "lightning" or "bullet", while they carry certain conventional connotations, do not have objective criteria. However, certain organizations may define these terms concretely within their own domains.

USCF

The USCF defines three time-control zones: Regular, Quick, and Blitz. Different sets of time controls fall into one (or more--it is possible for a game to count as both Regular and Quick, in which case the player's ratings in both categories are affected) of these categories. Determining the category is simple: calculate the [estimated] total playing time (TPT_U) as:

TPT_U = Minutes + SecondsPerIncrement

The TPT_U is then slotted into a zone as follows:

TPT_U > 65: Regular
30 ≤ TPT_U ≤ 65: Regular AND Quick
10 < TPT_U < 30: Quick
5 ≤ TPT_U ≤ 10: Blitz

FIDE

FIDE defines (as far as I can tell) two time-control zones beyond the standard FIDE time control: Rapid and Blitz. To determine which of these zones a time control falls within, calculate the [estimated] total playing time (TPT_F) as:

TPT_F = Minutes + SecondsPerIncrement

The TPT_F is then slotted into a zone as follows:

10 < TPT_F < 60: Rapid
TPT_F ≤ 10: Blitz

CHESS.COM

Chess.com defines three time-control zones: Standard, Blitz, and Bullet. To determine which of these zones a time control falls within, calculate the [estimated] total playing time in minutes (TPT_C) as:

TPT_C = Minutes + 2/3*SecondsPerIncrement

This assumes a forty-move game and is derived from the following expression (multiply the increment in seconds by forty, then convert to minutes):

TPT_C = Minutes + (40 * SecondsPerIncrement / 60)

The TPT_C is then slotted into a zone as follows*:

15 ≤ TPT_C: Standard
3 ≤ TPT_C < 15: Blitz
TPT_C < 3: Bullet

*I've had to extrapolate here, as the definition actually appears to leave a gap between 14 and 15 minutes. I've filled this gap in the manner I considered most likely to be accurate.

Examples

Base | Incr | TPT_U | TPT_F | TPT_C | USCF  | FIDE  | CHESS.COM
-----|------|-------|-------|-------|-------|-------|----------
 2   | 1    | 3     | 3     | 2.667 | N/A   | Blitz | Bullet
 3   | 0    | 3     | 3     | 3     | N/A   | Blitz | Blitz
 3   | 2    | 5     | 5     | 4.333 | Blitz | Blitz | Blitz
 5   | 0    | 5     | 5     | 5     | Blitz | Blitz | Blitz
 10  | 0    | 10    | 10    | 10    | Blitz | Blitz | Blitz
 10  | 1    | 11    | 11    | 10.67 | Quick | Rapid | Blitz
 14  | 3    | 17    | 17    | 16    | Quick | Rapid | Standard


Stockfish shows only 2 next moves For Position 1r2k1r1/pq1b1p2/1p1Rp1p1/2p1P3/2B2P2/P1N1K1P1/1P2Q3/8 b - -
stockfish analysis ouput is like
info depth 12 seldepth 17 multipv 1 score cp 258 nodes 80180 nps 76874 hashfull 14 tbhits 0 time 1043 pv b6b5 c3e4 b5c4 e4f6 e8f8 f6d7 f8g7 d7b8 g8b8 d6d2 b7b3 e3e4 c4c3 b2c3 b3a3 d2d3

info depth 13 seldepth 22 multipv 1 score cp 130 nodes 122237 nps 81437 hashfull 25 tbhits 0 time 1501 pv b6b5 c4d3

As you can see stockfish only show 2 moves sequences for depth 13 b6b5 c4d3,
Can I somehow force stockfish to show at least 5 moves sequences?

You can't. That's how Stockfish internally works. You are going to need to check your previous line with the current line. If the current line has fewer moves, discard it.


Opening theory overlooking simple moves? What is the most obvious move, (or simple sequence of moves) long overlooked by opening theory in the last 50 years or so, completely changing the evaluation of a well-known position?

EDIT: Well, I mean those cases in which "an unknown amateur from Siberia wrote to the famous chess magazine that White is losing, because after the simple 12...Nxc3, White cannot take back, because of the discovered check..." Are those just urban legends, or they did actually happen? I am curious...

Joe Gallagher says of 22... Kf8 in Starting out: the king's indian:

  Vaisser relates how for many years this move was thought to lose because of some erroneous analysis.

Of 25...Qf8 he writes:

  This came as a great shock for Vaisser. According to theory at the time Black was supposed to play 25...Ra6 and lose

[FEN ""]
[White "Vaisser"]
[Black "Bauer"]
[Startply "50"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f4 O-O 6. Nf3 c5 7. d5 e6 8. Be2 exd5 9. cxd5 Re8 10. e5 dxe5 11. fxe5 Ng4 12. Bg5 Qb6 13. O-O Nxe5 14. Nxe5 Bxe5 15. Bc4 Bf5 16. Nb5 a6 17. d6 axb5 18. Bxf7+ Kxf7 19. Rxf5+ gxf5 20. Qh5+ Kf8 21. Bh6+ Bg7 22. Bxg7+ Kxg7 23. Qxe8 c4+ 24. Kh1 Qxd6 25. Re1 Qf8 (25...Ra6 26. Re7+ Kh6 27. Qf8+ Kg5 28. Qg8+) 26. Qe5+ Kg8 27. Qd5+ Kh8 28. Qe5+ 1/2-1/2


Questions about the beginning of this game [Event "Live Chess"]
[Site "Chess.com"]
[Date "2018.12.29"]
[White "Leon_Likes_Chess"]
[Black "SmojLee"]
[Result "0-1"]
[ECO "B47"]
[WhiteElo "1625"]
[BlackElo "2310"]
[TimeControl "600"]
[EndTime "14:52:01 PST"]
[Termination "SmojLee won by resignation"]
[FEN ""]

1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 e6 5.Nc3 Qc7 6.Ndb5 Qe5 7.f4 Qb8 8.e5 a6 9.Nd6+ Bxd6 10.exd6 Nh6 11.Be2 Nf5 12.Ne4 b5 13.g4 Nh4 14.Rg1 Qb6 15.Nf2 Nd4 16.Be3 Ndf3+ 17.Bxf3 Qxe3+ 18.Be2 Nf3+ 19.Kf1 Nxh2+ 20.Kg2 Bb7+ 21.Kxh2 h5 22.gxh5 Qxf4+ 23.Rg3 Qxf2+ 24.Kh3 Qf5+ 25.Kh2 Rc8 26.Bg4 Rxc2+ 27.Be2 Qxh5+ 28.Kg1 Bf3 29.Qxc2 Qh2+ 30.Kf1 Bxe2+ 31.Qxe2 Qxg3 32.Qf2 Rh1+ 33.Ke2 Qxf2+ 34.Kxf2 Rxa1  0-1

This is a 20min rapid game I played with black and I have questions about the beginning of the game:

Question 1 - What was the purpose of 6.....Qe5, it looks like it loses a tempo and gives White an advantage

Question 2 - Doesn't 13.g4 weaken the White king?

Question 3 - Why 14. Rg1? White should really try to get his King to safety and focus on development

I would appreciate if someone can give me their thoughts about the rest of the game, thank you!

What was the purpose of 6... Qe5? It looks like it loses a tempo and gives White an advantage.

I think you are asking the wrong person. You said you were playing black, so, why did you play this move? Exactly as you say, it loses a tempo and worsens your position. 6... Qb8 was much safer.

  Doesn't 13. g4 weaken the White king?

I don't think so. White has a nice setup after 13... Nh4 14. Qd3, and even has the initiative as a kingside attack is ready to be launched against the black king. However, accurate play is required:

[FEN "rqb1k2r/3p1ppp/p1nPp3/1p3n2/4NP2/8/PPP1B1PP/R1BQK2R w KQkq b6 0 1"]

1. g4 Nh4 2. Qd3 f5 3. gxf5 Nxf5 4. Bh5+ g6 5. Bg4 O-O

The bishop defends f4, so white has nothing to worry about.

  Why 14. Rg1? White should really try to get his King to safety and focus on development.

I wouldn't say Rg1 is a blunder, though, as you said, development takes precedence here. The queen must take part in the kingside action via Qd3. You can also get your king to safety - the engines agree, but it is not a humane decision to get your king walking:

[FEN "rqb1k2r/3p1ppp/p1nPp3/1p6/4NPPn/8/PPP1B2P/R1BQK2R w KQkq - 1 1"]

1. Kf2 (1. Kd2? Bb7 2. Qe1 Ng6 3. Kd1 Nd4 4. Bd3 O-O {and the white king ends up exposed in the middle of the board.}) f5 2. Kg3 fxe4 3. Kxh4

Your play was almost perfect throughout the middle game, though you missed a mate-in-4 starting at move 28 (the position was winning for black anyways):

[FEN "4k2r/1b1p1pp1/p2Pp3/1p5q/8/6R1/PPr1B3/R2Q2K1 b k - 1 1"]

1... Qc5+ 2. Qd4 Qxd4+ 3. Kf1 Rh1+ 4. Rg1 Rxg1#


How can I train myself to become more observant of all my pieces? This is always what gets me. I want to find a way to train myself to become more observant, and able to look at every piece that's about to murder me.

As I mention here, not having any undefended piece greatly helps.

Each move, you have to check out for all your pieces, and after a few games of paying attention, it'll most probably become natural to know what pieces of yours are under somehow in peril, and not.
In case you missed some tactic, didn't count attacks and defenses well enough, whatnot, you always have at least one defender.
You'll start noticing overloads, which is probably a tactical trick beyond your level right now.

Eventually, you'll constantly have a map in your mind telling you :

this is attacked twice, defended by this and this : ✓
this is attacked once and defended by that : ✓
I can be put in check in various ways by his queen, but all my pieces are defended at least once : ✓
He just played this move, so this and that are threatened. I must find a move that defends both of them, e.g. moving one to defend the other, and I'll be fine.

Then, go look for problems that arise after multiple moves.


The engine is recommending Qc1 and I cannot figure why it is the best I tried a lot of variants to induce checkmate or gain material by moving the recommended move Qc1. I tried it instead of Nc4, which the engine considers a blunder. However, I cannot solve why it is the best move.
[FEN ""]
[StartPly "28"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Qf6 4. d3 Nge7 5. Bg5 Qd6 6. Bh4 Ng6 7. Ng5 Qb4+ 8. Nd2 Nxh4 9. Bxf7+ Ke7 10. O-O d6 11. Bb3 Nd4 12. c3 Qb5 13. cxd4 Qxd3 14. dxe5 dxe5 15. Qc1 (15. Nc4)

Consider the position before 15. Nc4.
[FEN "r1b2b1r/ppp1k1pp/8/4p1N1/4P2n/1B1q4/PP1N1PPP/R2Q1RK1 w - - 0 15"]

You have developed two knights, a bishop, and castled. Your opponent has developed a queen and a knight, and his king is stuck in the center.
In other words, you have a massive dynamic advantage! You are already in position to leverage your superior development & king safety and steamroll your opponent off the board. There are plenty of ways to do so - Rc1, Qc1, Qh5, they all produce immediate threats against your opponent's king that are hard to fend off. These moves even come with tempo because Black can hardly allow Qxc7+ or Qf7+.
Nc4, on the other hand, allows your opponent to trade queens. When you are on the attack this is one of the things you least want to do, because the queen is the most powerful piece and  hence also the most powerful attacker. After 15. Nc4 Qxd1, you still have a comfortable advantage, but you are no longer playing for immediate checkmate.
I haven't looked at the computer's suggestions and it probably sees something more concrete, but still: on general grounds, trading queens in this position is a bad idea. By extension, that makes Nc4 an inferior move.


How come chess prodigies seem to start at a young age? I started looking into the history of a few grandmasters such as Fischer and Carlsen, so I wondered: why does it seem that chess "kings" and queens" start playing the game from a young age? Can anyone show me any grandmasters who started playing chess after becoming 18? Does this situation apply to other things such as physical sports or even more mental-focused skills such as doing math?

In pretty much any endeavor that requires one to develop or acquire complex sets of skills, be it chiefly intellectual or chiefly physical, starting young will generally be a huge boon simply because of the fact that younger brains are more plastic than older brains; they can more readily adapt to new sorts of tasks and information. Because of that fact, chess will be no different from sports or math or whatever, and those who rise to the very top will tend to have started quite young, as that makes much easier the ultimate task of acquiring the specialized knowledge and skills that are necessary in order to play chess with the very best. Even so, some remarkably strong players have indeed gotten relatively late starts.

Mikhail Chigorin first learned the rules of chess at the fairly late age of 16, and didn't really throw himself into chess until he was already 23-24. A quote from Wikipedia:

  He became serious about chess uncommonly late in life; his schoolteacher taught him the moves at the age of 16, but he did not take to the game until around 1874, having first finished his studies before commencing a career as a government officer.

All in all, I think Chigorin thus reasonably meets your criterion of having started after age 18. Technically, he was not a "grandmaster" in the sense of having that official FIDE title, but of course that's only because it didn't exist in Chigorin's day. He played two matches for Steinitz's world championship, and chessmetrics places Chigorin in the world's top 4 players throughout the 1890s (peaking at #2 behind Steinitz and Lasker at different times).

In addition, Howard Staunton apparently started playing chess only at age 26. Like Chigorin, he of course was not technically a GM in the modern sense of the word, but he is generally recognized as having been the strongest player in the world the 1840s, and is sometimes referred to as an "unofficial world champion" the way that Paul Morphy often is.


How do I increase my chances to win as black in the Ruy Lopez? The Ruy Lopez is one of the most difficult lines for me to play against.  I just can't hold my position when I play as black. If I move 3... Nd4, I always get a draw at best, and usually take a loss. How can I improve my chances of winning in this situation?

EDIT :
After I looked up the answers which were given to me, I found one solid win for black with the Cordel Defence that I found in Shredder Computer Chess if you insert this FEN to it.

[FEN ""]
1. e4 e5 2. Nf3 Nc6 3. Bb5 Bc5 4. c3 Bb6 5. d4 exd4 6. cxd4 Nce7 7. d5 Nf6 8. Nc3 O-O

Can someone show me, at which point does black take the initiative from white??

Thanks,
Ahmad

The Ruy Lopez is probably one of the most analyzed openings in chess. You can find plenty of resources on the Internet. (Wikipedia's article on the Ruy Lopez is a good point to start).

I would recommend that you not go searching for "winning lines". You first need to understand the principles that lie behind each move of this opening. Once you have that understanding it is easier to examine variations and choose the one that best suits your needs.

For example, if you are an aggressive player and your chess level is average, you might wish to consider the Open Defense and the Marshall Attack.


How good is 1. e3 2. c4 as an opening for White? How good is 1. e3 2. c4 as an opening for White? Afterward, developing the knight on b1 to c3, and developing the bishops too, it seems good. Castling is preferably done on opposite sides as well.

Overall, I wouldn't suggest it, especially for a beginner. There are better ways to fight for an advantage.
By playing e3 first, you are allowing your opponent to do almost whatever they like on their first move. Are you OK with them playing 1...d5? Is that going to prevent you from playing c4? If that's going to be a problem, you may want to play 1.c4 first instead (which is the much more reputable English opening.)
With a pawn on e3, your c1 bishop has limited scope. Perhaps you want to fianchetto it to b2? Otherwise, it's either stuck on d2 where it doesn't do much, or you need to play e4 to free it, which perhaps means that e3 was a waste of a tempo.
Castling on opposite sides seems like it's something you need to decide later - don't do it if you aren't in the right position. If your opponent castles kingside (which they usually do), then castling queenside means that you're putting your king on the c-file, behind a pawn you've moved two squares (and if you've fianchettoed the c1 bishop, the b-pawn has also moved.) Depending on what your opponent has been doing and how open the game has become, this may be a bad idea.


Do the new chess AIs play gambits? Do the new chess AIs, such as Alpha Zero and Leela Zero, play gambits?

By gambit, I do not mean a merely nominal gambit like the mainline Queen's Gambit, but rather a genuinely speculative offer of opening material like Evans' Gambit, for example—or like the gambit @Akavall gives below.

Sure, this line of Queen's Indian came up:

[FEN ""]
[White "AlphaZero (Computer)"]
[Black "Stockfish (Computer)"]

1. Nf3 Nf6 2. d4 e6 3. c4 b6 4. g3 Bb7 5. Bg2 Be7 6. O-O O-O
7. d5 exd5 8. Nh4 c6 9. cxd5 Nxd5 10. Nf5 Nc7 11. e4 d5
12. exd5 Nxd5 13. Nc3 Nxc3 14. Qg4 g6 15. Nh6+ Kg7 16. bxc3
Bc8 17. Qf4 Qd6 18. Qa4 g5 19. Re1 Kxh6 20. h4 f6 21. Be3 Bf5
22. Rad1 Qa3 23. Qc4 b5 24. hxg5+ fxg5 25. Qh4+ Kg6 26. Qh1
Kg7 27. Be4 Bg6 28. Bxg6 hxg6 29. Qh3 Bf6 30. Kg2 Qxa2 31. Rh1
Qg8 32. c4 Re8 33. Bd4 Bxd4 34. Rxd4 Rd8 35. Rxd8 Qxd8 36. Qe6
Nd7 37. Rd1 Nc5 38. Rxd8 Nxe6 39. Rxa8 Kf6 40. cxb5 cxb5
41. Kf3 Nd4+ 42. Ke4 Nc6 43. Rc8 Ne7 44. Rb8 Nf5 45. g4 Nh6
46. f3 Nf7 47. Ra8 Nd6+ 48. Kd5 Nc4 49. Rxa7 Ne3+ 50. Ke4 Nc4
51. Ra6+ Kg7 52. Rc6 Kf7 53. Rc5 Ke6 54. Rxg5 Kf6 55. Rc5 g5
56. Kd4 1-0

I got this game from chessgames.com: game


Is it a good habit for an amateur to always try to play the best move (according to his best calculation and knowledge)? Is it a good habit for an amateur to always try to play the best move (according to his best calculation), instead of sometimes purporsely play an inferior move hoping that his opponent does not know how to take advantage of it?

For example, this implies avoiding playing slightly inferior but playable lines such as the exchange variation of Ruy Lopez, the king's gambit, or (as black) the queen's gambit accepted, or setting up a trap which objectively is not the best move in a particular position, but when your opponent does not see through it, you gain some advantage.

I personally feel that purposefully playing an inferior move may be helpful with obtaining advantages (and therefore winning chances) in a particular game, but may not be the best strategy, if not harmful, to one's life-long learning process of chess

So, is it a good habit for an amateur to always try to play the best move?

This question is related. But my question is more about improving one's chess strength instead of winning a particular game.

This is a complicated question since chess is very complicated, and both board, and time, factors may be part of a decision.

Overall, yes, you should always play the best move probably 99% of the time. If there is a second alternative, but it is not much worse, and you think that your opponent might get caught up somehow, you can consider it. If it is genuinely just bad, then no, avoid it.

Recently, in a game, I was playing someone well below me, and I played a move that sacrificed two pawns, but I played it knowing it was incredibly dangerous, and that he did not have enough time to figure it out. Well, my reasoning was sound until the tournament director walked by, and realized that the increment was set wrong, and was going to add time. My opponent, graciously, offered a draw, which was accepted.

There is one more case that I can think of, and that is if you know the style of your opponent. Let's say he is known not to defend well, and you have the choice between a positional move, and an attacking, but maybe not sound, move. If you are a good attacker, then it might be worth it given his known weaknesses.

Those first openings that you listed are not really inferior, but rather, might not give as much opportunity for an opening advantage, especially the King's Gambit. That is mitigated at lower levels, where opening theory is not memorized as deeply. The QGA is a bit more dangerous as it, generally, does cede a definite slight plus to white.

So situational chess is a thing, but do not go overboard playing horrible moves that can bite you. Also, everything is out the window if you are significantly worse: In that case, do whatever you can to complicate the position, and make it tricky for your opponent.

As far as improving one's strength, and game-situation aside, yes, you should always try to find the best move.


Is it possible to have a double self-smothered stalemate? I came up with this rather amusing and bizarre stalemate where Black stalemates itself by self-smothering.

  [FEN "8/8/8/8/8/3p4/pp6/krb1K3 b - - 0 1"]

  1...d2+?? 2. Kd1

The peculiar feature of this stalemate is that Black is unable to move not because moving a piece would put its king into check, but moving a piece would require it to capture its own piece, which is disallowed. This is an example of a single self-smothered stalemate.

The question is, is it possible to have a double self-smothered mate, such that both sides do not have any moves at all because the moves would require capturing of the side's own pieces?

One possibility suggested by the user supercat is the following -

      [FEN "KN1b4/RPpPp3/P1P5/4P3/8/3p1p1p/3PpPpr/4B1nk w - - 0 1"]

      1. e6

And both sides are stalemated. However, this position cannot occur in practice, because you cannot have a Black bishop trapped on d8 with the c7 or e7 pawns still on their original squares.

I think I found a double-self-smothered-stalemate that could occur via sequence of legal moves from the normal starting position.

 [FEN "5bnk/4ppbp/4P2p/5P1P/p1p5/P2p4/PBPP4/KNB5 w - - 0 1"]

  1. c3 f6

Each player has seven pawns and two dark-square bishops, so one pawn from each player must have been promoted.  Once White's b pawn has captured to a3 and Black's g pawn has captured to h6, White's g pawn and Black's b pawn can promote without any other pawn having to leave its file.  I haven't worked out the exact "game", but I see no reason to believe it wouldn't be relatively trivial, particularly if one isn't worried about achieving the position with a minimal number of moves.


Are there consumer-level game play analysis systems that overlay the analysis on the board real-time? An example of what I mean would be Thinking Table, though the Thinking Table is not a consumer product:

  Thinking Table is a series of works that explore the invisible, elusive nature of
  thought. Play chess against a transparent intelligence, its evolving
  thought process visible on the board before you.

CAPTION: The above image is three images, from left to right, the images are of the opening, middle, and end of the same game. The lines shown on the board are the engine's "thoughts" for one move during the game.

  Each Thinking Machine is an artificial intelligence program – ready,
  willing and able to play chess with the viewer. If the viewer
  confronts the program, the computer’s thought process is sketched on
  screen as it plays. A map is created from the traces of literally
  thousands of possible futures as the program tries to decide its best
  move. Those traces become a key to the invisible lines of force in the
  game as well as a window into the spirit of a thinking machine. The
  pace of interaction is deliberative, unlike the rushed tempo of
  popular video games. Indeed the true subject of the piece is not games
  or chess, but contemplation and introspection.

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

Example of Fritz visual output:

SOURCE: Visualize search in Fritz 10 (21.05.2007)


How to correct reversed game notation? My son and I are rank chess amateurs, and we wanted to play our first "real" game where we keep track of moves to analyze later.  We started the game but then realized that the board was reversed (i.e. the black pieces were on rows 1 and 2).  Since we didn't notice until a few moves had been played, we just continued to use this reversed notation for the whole game.

The resulting PGN file doesn't want to import into lichess.  Is there any way to take our "reversed" PGN game file and make it compatible?  Perhaps some automated way to reverse the notation, or alert the PGN importer that the notation is reversed so it can handle it?

Adding on to Brian Towers' answer, there is a quick way you can script this (assuming you are on Linux or another POSIX system with the tr command):

cat gamelog.txt | tr 'abcdefgh12345678' 'hgfedcba87654321' > gamelog_reversed.txt

Edit: as @wimi said, this will mess up move numbers, so be careful about that. You may want to use cut and paste to seperate only the columns with the moves.


What's is the Least significant File and Least Significant Rank? I'm Reading this tutorial and there are 2 definitions that confuse me :

https://chessprogramming.wikispaces.com/Square+Mapping+Considerations

What's is the Least significant File and Least Significant Rank ?

LSF and LSR are two ways to encode a chess board coordinate into a single integer number. LSF does that by { a1, b1, c1, ... } while LSR encodes by { a1, a2, a3 ... }.


Players who play fast in longer time control games I see it all the time on the net. Some players play, for example, a 15-minute game with a 10-second increment, and they finish the game with more time than what they started with! I've heard players doing this even in OTB tournaments- games that could go on for hours on end.

Is it because they are perhaps too impulsive? (And if so, why not just play bullet?). Or do they like to just use their gut? Is it also a bit an ego thing, as in, "I can beat this guy even if I don't think at all!". Or is it also a part of their strategy, they want to get their opponent in time trouble?

So what are the possible reasons why they play so quick?

As I commented, there are several reasons why people play fast, among them:

One of the reasons I often see is fear of time trouble. Many amateurs are not really aware of whether the time they have left will "be enough", so start to move way too fast early on. They won't feel confident to play faster games either for that same reason.

It could be the case that your opponents are using your time to think if you take too much time, so when it's their turn they've already anticipated your move and figured out how to answer.

Other players want a challenge, so they will play a game in 5 minutes against an opponent who has 15.

The list could be infinite...


At what level does being very aggressive stop being useful? Aggression is very good against weaker players. But too much aggression is bad, and the higher the level of play the more you need to dial it back to be safe.
What is the point in ratings in which one should look more to playing positionally and stop going all out for attack and tactics? This is in order to avoid losing with barely inferior moves that a weaker player could not find a good response to, but a high rated player can refute.

Whether aggresive or not, good chess works against all players. Bad chess does not "work" against anyone, but you can still beat a weak opponent in spite of it.
There are positions that require aggression, others that don't. After 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4. Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3, aggressive play is the only way you can beat a GM. After 1.e4 e6 2.d4 d5 3.exd5, you should expect to be in a quieter game.
There's also a trend towards aggressive play requiring more opening theory to rely on (as mistakes will pay a higher price)


Is there a free online chess repertoire tool? Is there a free online chess repertoire tool? It can be some place where you register, save variations and comments, and navigate with a board what you do. I was used to chessply, but apparently it disappeared.

In addition to the other answers, there are a few sites to consider. These include annotation and comment features as mentioned by the OP.
Listudy.org
Upload a PGN and then you play the computer interactively. You play moves from your repertoire and the computer plays the opponent moves. This is also open source.
ChessTempo.com
Similar functionality in the "Opening Trainer." The interface is a bit different but it tracks what lines you have learned a bit differently which is nice.
lichess.org
As B.Swan has pointed out in a comment.

There are also other related sites worth exploring to understand their capabilities and how they may supplement the resources above.
ChessTree.com
Import/export PGNs. Search databases, get statistics. See opening relationships in a graphical tree.
OpeningTree.com
Import/export PGNs.  Import and analyze a user's openings from a database, PGN, etc, including popular online chess sites.


Using the diagonal in perpetual queen checks? There exists a heuristic that recommends checking from the diagonals (using a queen) in order to get a perpetual. This, I expect, is a rule that is meant for the worse player in queen and pawn endgames. My question is, why does checking from diagonals ensures, or at least raises the probability, for a draw?

As you said, this is a very general guideline, but looking back it has served me well in practical play.

Note that by "checking from the diagonals", the pattern I have seen is that the queen maintains a stable circuit on a diagonal but the checks themselves are usually horizontal or vertical.

I think it's because the checks from a diagonal allow the queen to keep the king in a box with only minimal pawn support (a single nearby pawn for either side will usually do it). Checks from a file or rank each allow the king to run across the board in one direction unless there's a pawn directly blocking his path.


Top players have seconds to help them prepare. Do they also use engines looking to prepare lines for surprise value? What just do seconds add to a players preparation for a BIG match?   Do they use engines to help them prepare better surprising moves?

Wouldn't a room full of powerful computers running around the clock help prepare better than seconds?  Or do the seconds only transfer info from computers to the Player in the match.

Seconds, and the players themselves, absolutely use engines to help them find moves, but you cannot just let an engine run and think that it will spit out useful things. There would be too much information, and most of it useless.

First, nowadays, more and more, elite players are resorting to using Leela and Fat Fritz (neural network type programs) since they tend to be better at finding better opening moves. Stockfish is still the king when it comes to brute-force analysis in the middlegame.

Second, if you assume that the game is relatively equal from the opening, just letting a computer run theoretically should not find anything except a lot of equal lines since it will only analyze best moves for both sides. You need human intervention.

That is where the second comes in. Most seconds are very strong GMs with a great depth of theoretical opening knowledge and understanding, and they look at a position, and come up with an idea that they want to test in the player's main lines, and they basically play "advanced chess", combining their great human understanding with the computer's immense analytical ability. Of course, it is not impossible that they will stumble upon a clearly winning line, but at that level, both sides have thoroughly checked their opening repertoire with computers, and the players have such a strong positional understanding, that it is highly unlikely they would play something that weak in the first place, computer-checked, or not. They are simply looking for new move that leads small advantages that lead to an uncomfortable game for the opponent...a game they can press for a long time, hoping that it will create an unforced error.


What does it mean to play "positionally", and how do you train that? I often hear this term thrown around when people are analyzing chess, but I don't really know what it means. I assume it's a generic term that means to play defensively, or to set up for the future. If that's what it means, how do I learn when it's time to do that, and how to do that? If the meaning is more precise than that, what is it?

There are three general types of players: Positional, tactical, and universal, which is being adept and comfortable in both positional and tactical games. Tactical means that you love open positions that require a lot of calculation, and often include all-out attacks.

Positional chess is generally slower, and you work to build small advantages by placing your pieces and pawns on good squares. Using your pieces and pawns effectively, you gradually hope to create pressure and threats that force small (or large, if you are lucky) weaknesses in your opponent's position. Once you have one small advantage, you can often accumulate more small advantages, and with the accumulation of these small advantages, you hope to turn that into one big advantage with a final winning tactical maneuver, or "tactical shot".

I gave a very detailed list of positional elements in this post. Be aware that positional sense is one of the last things that a chess player develops, and it takes a lot of time to develop. Most players are pretty experienced by the time they really start to understand this well.


Fastest Way to Amass Experience I want to amass as much Chess experience as I can, by playing several games against my phone/laptop AI.

I'm not a good player, and would estimate my ELO is <1500.

I am wondering if I would level up fastest by playing against an AI closer to my level, or by playing against my AI at the highest level.

I've known the rules of chess for several years and been playing casually — I want to start playing seriously.

What I most desire, is experience — and the intuition that comes with.

Playing against machines will definitely help you get better at playing against machines.  If that's the goal, go for it.

If you want to get better at Chess, you need to play several slow serious games against human opponents (both slightly above and below your skill level) on a regular basis.

The metaphor here is picking up a "learn some language in 6 months" interactive audio/software course that you do solo vs. being thrown into a village where that  is all that people speak and your ability to survive and grow  is acquired organically by making mistakes, getting critiqued with regular feedback loops as well as the social osmosis that is typical of increasing competency in any learning fraternity.

Even the mighty self-taught Fischer visited the clubs and competed against the world's finest to get from good to better.

There's also an aspect of gamesmanship, learning how to use the clock under pressure, deceptive stratagems and sub-optimum "play the man" ideas like gambits that you will NEVER pick up when practicing against a machine.  Gaining experience and intuition in a very short window of time is best achieved with a human feedback loop to help you constantly identify your weaknesses and recommend avenues of play (openings, endings, middlegame strategy) that you are clearly missing.

With that being said, seeking out human opponents at any time control is fairly easy these days via your laptop/tablet/mobile device. For instance sites like Chess.com,  Playchess and the ICC provide mobile-friendly apps that you can certainly use to get some chess in at all times of the day against human opposition.

For your kind of ambition though,  start hitting your local clubs and find (and in some cases, pay) a strong mentor to review each and every slow game you play as often as possible.


What algorithms and heuristics are popular in computer chess? Computer chess has exploded in the last twenty years, with a computer world championship being established and many chess computer designers becoming quite profitable from their endeavors.  Some of the programs hide their source code, but a great many are open source, most notably Fruit, which served as the basis for a family of chess engines.

What are some examples of heuristics or algorithms used by chess computers, and which have been most successful or are most popular?

Algorithms mainly used are based on searching the state space. The problem is that the possible positions a piece can make in the next move is very huge. But it is finite. It is basically a search problem. There is a valid position a piece can take. That is there is a known start state and a know end state. There is no probability involved like the problem of tossing a coin.
A typical algorithm is to use brute force and compute moves for a fixed number of moves. MiniMax can be used in such cases. Alpha-beta pruning is also a well know algorithm used. Mostly the search spaces are represented using a tree based data structure.
Computer program also heavily use databases containing moves, openings, end-game positions etc.


A position with a choice between checkmate and perpetual check For some odd reason I'm searching for a game, or rather a position, where one player can force a win via checkmate (can be check in n, where n is any number), but they can also force a draw via perpetual check (again, maybe the perpetual check comes about a few steps later, but the player has an assured path to it).
A real, historical game would be a bonus, and a game between two skilled players will be even better. But constructed positions, even weak ones, will be appreciated, too.

Here is one game which should match your request (Swiderski, Rudolf vs. Nimzowitsch, Aaron):
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.c4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Nbd7 5.e3 c6 6.Nf3 Be7 7.Qc2 O-O 8.Rd1 Re8 9.Bd3 dxc4 10.Bxc4 Nd5 11.Bxe7 Qxe7 12.O-O b5 13.Bxd5 cxd5 14.Nxb5 Ba6 15. Qa4 Bxb5 16.Qxb5 Reb8 17.Qe2 a5 18.Rc1 Qd8 19.Rc3 a4 20.Rfc1 Qa5 21.Rc7 Nb6 22.R1c5 Qb4 23.a3 Qb3 24.Ng5 Qa2 25.h3 Rf8 26.Kh2 h6 27.Nxe6 Rfc8 28. Qf3 Rf8 29.Qg3 g6 30.Qxg6+ fxg6 31.Rg7+ Kh8 32.Rcc7

In the ending position white has a forced mate, e.g.:
[FEN "r4r1k/2R3R1/1n2N1pp/3p4/p2P4/P3P2P/qP3PPK/8 b - - 3 1"]

1... Nd7 2. Rcxd7 Rf7 3. Rdxf7 Qxb2 4. Rh7+ Kg8 5. Rfg7#

Alternatively, he can force a draw, e.g:
[FEN "r4r1k/2R3R1/1n2N1pp/3p4/p2P4/P3P2P/qP3PPK/8 b - - 3 1"]

1... Nd7 2. Rcxd7 Rf7 3. Rdxf7 Qxb2 4. Rh7+ Kg8 5. Rhg7 Kh8 6. Rh7+ Kg8 7. Rhg7 Kh8

Probably any game ending in a Blind Swine Mate would work.


Is there a freely available online 7 piece Endgame tablebase? The only 7 piece site I heard about is http://tb7.chessok.com/ , and upon registration I am able to setup various positions with 2-6 pieces . However as soon as I setup a position with 7 piece, I get an error about service not being avaiable. Has anyone had better luck or know of any other site with 7 pieces tablebases?

Update: in the end I discovered that FinalGen solved a vast majority of positions I was interested in, included those with more than 7 pieces. http://finalgenchess.ovh/home_ing.php

Original Answer:

7-men Lomonosov is free as an Android application.

Update - September 2018:

7-men Syzygy is available for free. Also available from Lichess.


Do FIDE rules allow listening to music while playing a tournament game? I played a FIDE tournament recently and was surprised to see that some players had earphones on and were listening to music (or that's what it seemed like they were doing) while playing their games. One of my own opponents did this.

Is this allowed as per FIDE rules?

The closest thing which I could find in the FIDE Laws of Chess is

12.3 a. During play the players are forbidden to make use of any notes, sources of information or advice, or analyse on another chessboard
12.3 b. Without the permission of the arbiter a player is forbidden to have a mobile phone or other electronic means of communication in the playing venue, unless they are completely switched off. If any such device produces a sound, the player shall lose the game. The opponent shall win. However, if the opponent cannot win the game by any series of legal moves, his score shall be a draw.

However, I'm not sure if music from earphones would be considered as "source of information" or an "electronic means of communication". The competition rules may specify that any kind of electronic equipment is disallowed, and the arbiters have the right to arbitrate things like these as long as their decisions are not unfair or contradictory to the laws of chess.
But the arbiter cannot know whether it is music or someone reciting a chess book, so I understand if some people strongly object to arbiters allowing players to have earphones. At least I've never been to a tournament where using earphones was allowed.
Note that if other players can hear the sound from the headphones, it violates this rule:

12.6 It is forbidden to distract or annoy the opponent in any manner whatsoever. This includes unreasonable claims, unreasonable offers of a draw or the introduction of a source of noise into the playing area.


How can I improve and get to know the game? I'm just starting at chess and I would like to understand better the game itself , and if possible some tips on how to get better.

Chess is a game of strategy and tactics. Each player commands an army of 16 chessmen --- pawns and other pieces (the king, queen, bishops, knights, and rooks).

A well-played chess game has three stages. In the opening, the players bring out their forces in preparation for combat. The middlegame begins as the players maneuver for position and carry out attacks and counterattacks. The final stage is the endgame when, with fewer pawns and pieces left on the board, it is safer for the kings to come out and join the final battle.

As play proceeds, each player will capture some of the opponent's men; often, the capturing pieces are immediately recaptured. As long as the piece a player gives up is generally equal to the piece he gets in return, we say the players are exchanging. If you unintentionally place a piece where it can be captured without getting a piece of equal value in return, we say that you put that piece en prise. (This is a French term that literally means "in take.") Sometimes a player may place a piece en prise in order to trick an opponent. If the opponent captures the offered man, it may leave him open to attack.

You're Ready to Go!

It's time for you to take a look at these ten tips to help you learn some simple ways to win more games:

1 Look at your opponent's move.
2 Make the best possible move.
3 Have a plan.
4 Know what the pieces are worth.
5 Develop quickly and well.
6 Control the center.
7 Keep your king safe.
8 Know when to trade pieces.
9 Think about the endgame.
10 Always be alert.

Don't rush. Take your time and be sure to study the examples carefully


King's gambit line refutation In the King's gambit, a strong opponent has played against me(as black):
1.e4 e5 2.f4 exf4 3.Bc4 h6(trying to hold onto the f-pawn).
I have found a variation where White probably has a strong initiative, but he still insists that Black is fine and is slightly better.
4.d4 g5 5.h4 Bg7 5.hxg5 hxg5 6.Rxh8 Bxh8 7.Qh5
I have stopped my analysis here, since Black has a refutation 7... Qf6. I put this position into the engine, which gives White a large advantage, but Black has an extra pawn. Where did I go wrong?

So I'm not sure if you're asking where you went wrong analyzing this line for Black (because of the large advantage the engine gives to White) or for White (because you think Black being up a pawn is important).
If you mean analyzing for Black, 4...g5 is a poor move (3...h6 is also not great, although Black still seems alright). There are a few better moves, such as 4...d5. The point is to meet 5.Bxd5 with 5...Nf6, and 5.exd5 with 5...Bd6. Probably a more challenging try for White would have been 4.Nc3, aiming to prevent ...d5. Coming back to Black's point of view, by the time 6.hxg5 is played White already has a clear edge. But still a better response would have been 6...Nc6 or 6...d5; 6...hxg5 gives White a winning position.
If you mean analyzing for White, the only arguable improvement in your analysis is 4.Nc3 instead of 4.d4. By the final position after 8...Qf6, the engine gives White a huge advantage - the lost pawn is irrelevant. White could follow up with Nc3, Nf3, e5, etc, enjoying an overwhelming initiative. Reaching this position is a disaster for Black, and definitely not for White.


Help needed to find a Swedish opening It appears that openings are named after almost any country or city in the world. Spanish opening, Italian game, French defense, Hungarian gambit, London system and so on.

Because I am from Sweden I want to learn and play an opening related to Sweden. But to my surprise and dismay I haven't found a single one named after a Swedish location or Swedish chess player (Scandinavian Defense doesn't count because it is for the whole of Scandinavia).

Can you help me find one? The more closely related to Sweden the better.

The Swedish Variation of the Tarrasch Defense is the move 6...c4 in the line below. The name is also used for the same plan in slightly different positions with the same pawn structure.

[FEN ""]

1.d4 d5 2.c4 e6 3.Nc3 c5 {Tarrasch Defense} 4.cxd5 exd5 5.Nf3 Nc6 6.g3 c4 {Swedish Variation}

Its ECO code is D33. Black tries to capitalize on his queenside majority, while White is going to play e2-e4. I think theory considers the line dubious right now.

There is also the Göteborg variation in the Najdorf Sicilian, famous for its origin story. In 1955, one of the Interzonal tournaments was held in Göteborg, and in round 14 it happened that three Argentinian grandmasters (Panno, Pilnik and Najdorf) had black against three Soviet grandmasters (Geller, Spassky and Keres). All three reached the position below with the new move 9...g5 that the Argentinians prepared beforehand, and all three Soviet players reacted with the same piece sacrifice 11.Nxe6 and won.

[FEN ""]

1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Be7 8.Qf3 h6 9.Bh4 g5 {Göteborg Variation} 10.fxg5 Nfd7 11.Nxe6 fxe6 12.Qh5+ Kf8 13.Bb5

I think it's considered drawish these days.


How do convert/parse/extract data from a PGN into a spreadsheet/google sheet/excel file? Sequel to this question: Live statistics chess960 from chess.com?
So suppose I go to like
https://api.chess.com/pub/player/gmwso/games/2020/12
or
https://api.chess.com/pub/player/gmwso/games/2020/12/pgn
there's gonna be a bunch of stuff like say
[UTCDate "2018.01.03"]
[WhiteElo "2706"]
[BlackElo "2940"]

How do I get this data into a spreadsheet like column 1 is all the dates, column 2 is the corresponding white elo, column 3 black elo, col4 white username and col5 black username?

Update 2: Fixed now. see the 'json' vs the 'preformed'. WOW.
Update 1: It appears Mike Steelson has an answer here, where the code is given as
=arrayformula( regexextract(split( substitute(substitute(substitute(getDataJSON(A1;"/games";"/pgn");"[";"");"]";"");"""";"") ;char(10));"\s.*") )

with an example given here
https://docs.google.com/spreadsheets/d/1MX1o5qdy0K3gTMzbimUV3SmFf-0XPCSJ8Vz4IjI-8Ak/copy
It appears there's a problem when it gets to the case of chess960 only. Consider for example this player: Replacing 'gmwso' with the player's username will yield a weird output. i imagine the output will be messier for mixed chess960 and chess.

How do I get this data into a spreadsheet like column 1 is all the dates, column 2 is the corresponding white elo, column 3 black elo, col4 white username and col5 black username?

From the .pgn file downloaded at
https://api.chess.com/pub/player/gmwso/games/2020/12/pgn
I have created a file called chess_games.xlsx and I have inserted the five values you are asking using a python2 script. You need to install chess and openpyxl libraries with pip. The .pgn file is read as a long string.
import pgn
import openpyxl
import os

pgn_text = open('ChessCom_gmwso_202012.pgn').read()

dates = []
welo = []
belo = []
white = []
black = []

whiteLong = []
blackLong = []

def getValues(file):
    test_str = file
    test_date = "[Date"
    res1 = [i for i in range(len(test_str)) if test_str.startswith(test_date, i)]
    test_welo = "[WhiteElo"
    res2 = [i for i in range(len(test_str)) if test_str.startswith(test_welo, i)]
    test_belo = "[BlackElo"
    res3 = [i for i in range(len(test_str)) if test_str.startswith(test_belo, i)]
    test_white = "[White "
    res4 = [i for i in range(len(test_str)) if test_str.startswith(test_white, i)]
    test_black = "[Black "
    res5 = [i for i in range(len(test_str)) if test_str.startswith(test_black, i)]
    for i in res1:
    dates.append(test_str[i+7:i+17])
    for i in res2:
        welo.append(test_str[i+11:i+15])
    for i in res3:
        belo.append(test_str[i+11:i+15])
    for i in res4:
        whiteLong.append(test_str[i+8:i+43]) //The max length of a nickname in chess.com is 35 characters
    for i in res5:
        blackLong.append(test_str[i+8:i+43])
    for value in whiteLong:
        posClose = value.find("]")
        white.append(value[0:posClose-1])
    for value in blackLong:
        posClose = value.find("]")
        black.append(value[0:posClose-1])

def generateExcel(dates,welo,belo,white,black):
    file = 'chess_games.xlsx'
    if os.path.isfile(file):
        wb = openpyxl.load_workbook(filename=file)
    else:
        wb = openpyxl.Workbook()
    ws = wb["chess_games"]
    for k in range (len(dates)):
        ws['A'+str(k+1)] = dates[k]
    for k in range (len(welo)):
        ws['B'+str(k+1)] = welo[k]
    for k in range (len(belo)):
        ws['C'+str(k+1)] = belo[k]
    for k in range (len(white)):
        ws['D'+str(k+1)] = white[k]
    for k in range (len(black)):
        ws['E'+str(k+1)] = black[k]
    wb.save(file)

getValues(pgn_text)
generateExcel(dates,welo,belo,white,black)

Download the output .xlsx file


How to decide whether to exchange (good/active) bishops I have read about exchanging bishops for knights and inactive bishops for active one. I still don't know how to decide when both sides’ bishops are seemingly equally active. For instance, I have read that in the London system, Black should try to exchanging dark squared bishops because White supports
key target of e5. What about this position?
[FEN "rkq1n1rn/ppp1pbb1/3p2pp/5p2/3PP3/2P1NP2/PP4PP/RKQ1BBRN w - - 0 1"]

White could try exchanging light squared bishops with Bc4. Black would have to exchange, keep the tension, or do e6 and have his bishop trapped behind this pawn. If Black keeps the tension, it would be up to White to decide whether to also wait or exchange? Whom would benefit the exchange? Both bishops have the same open diagonal, the main difference to me is that Black's point toward White's king and not the other way around, but in the London system Black is advice to exchange his bishop, that targets White's king.

This position is from an early stage of a 960 game where the pawn position has not yet stabilized and it has little in common with the London system. Both sides will probably need to move some more pawns to get their pieces out, since particularly the Rooks and Knights are clumsily placed. A plan for either player must be comprehensive, taking account of all the pieces, and could go in many directions, depending in part on what the opponent decides to do. At this stage of the game it would be a mistake to focus too narrowly on the Bishops
In the London system, White aims at establishing a slight advantage in space, giving him more freedom than Black to manoeuvre. Any exchange of pieces will ease that aspect of .Blacks problem, and often this is accomplished by playing ...d5,..e6, and ..Bd6.
The downside (There is usually a downside) is that Black will be left with a light-square Bishop that is somewhat restricted by its own Pawns.
A situation often arises in the London system where the Bishops are on d6 and g3. In that situation Black usually should not exchange if he has already castled short and Whites Rook is still on h1. So the decision can depend on much more than the relative merits of the Bishops.


Can playing blindfold improve playing non-blindfold? If I play blindfolded or don't look at the board and just visualize the board, pieces and position in my head, can this improve my regular style of play (physically looking at a board).  Is there any proof to improving regular play via blindfold play?

I don't think there's any proof (nor do I think you'll find any), but I think playing blindfold definitely helps as regular chess practice. The better you can play blindfold, the more you can visualize the board and calculate ahead, in my opinion.

Better yet, try playing blindfold against someone who's not.


Is there a word to count one moving by one player? Is there a word to count one moving by one player?
For example, the following series of moves:

e4 e5 2. Nf3 Nc6 3. Bb5 a6

is counted as three moves. But if I want to denote "e4" as a unit of a count, what word should I use?

There is indeed such a word for so called "half-moves." The terminology used is the word ply. To speak of multiple ply, plies is used. One would refer to the move "e4" as the first ply of the game.  An example demonstration of it can be seen at work in CSE's very own diagram viewer.
Sometimes, a user wants to add a game to their post, but wants the diagram to start with a specified board position. For example, this question would look like the below picture without the word "ply" to refer to the wanted position.

But with the code [startply "38"] having four spaces in front of it, the page, when loaded, shows the position after Black's 19th moves, i.e. the 38th ply, and before White's 20th move, the 39th ply.

White's ply count will always be odd while Black's will always be even. Do note that while "half-move" is a broadly used term as well, it is basically a laymen's term, and "ply" is the offical one.


Do the official rules of chess forbid promoting a pawn to a piece of the opposite color? Not that it would be everyone's first choice, but it is possible to concoct positions where having an extra piece block your opponent's moves and thus gives you an advantage (think blocking an escape route for a checked king...)

Yes.

FIDE Laws of Chess, rule 3.7e:

  When a pawn reaches the rank furthest from its starting position it must be exchanged as part of the same move on the same square for a new queen, rook, bishop or knight of the same colour.

The Wikipedia article on promotion contains some information about the history of the rule, which previously implicitly allowed promotion to a piece of the opposite color.


It is important to play e4 or d4 to 'control the center'. Myth or reality? Well, there are two premises in the question itself: 1) That e4 or d4 'controls the center'. 2) That 'Controlling the center'is something important. It appears to me that 'controlling the center' is the least of the benefits of a move  like e4 or d4. The fact is that it becomes mandatory to play e4 or d4 if you want to develop both bishops along their long diagonals(c1-h6 diagonal or a6-f1 diagonal). This seems to be the most important benefit of e4/d4 IMO and not 'controlling the center'. So while it may turn out that 1) e4 and 1) d4 give rise to good games for white I feel it may be more due to the rapid development which these moves allow rather than because these pawns 'control the center'. Indeed, sometimes, these pawns can be an obstacle for white's own pieces.(I am looking at things from white's perspective but the same argument can be similarly posed from the black player's perspective as well.). Do post your thoughts on this.

Let me start from top to bottom:

  It is important to play e4 or d4 to 'control the center'. Myth or reality?

Myth.

  Well, there are two premises in the question itself: 1) That e4 or d4 'controls the center'.

When you play 1.e4/d4 you do not control the center, you physically occupy it.

To control the center, you will need more than a single pawn move-you need certain amount of developed pieces coordinated to control certain central squares.

1.e4/d4 simply fights for the center, you can not control it with just one pawn move-wish if it was that easy :)

Most importantly-you can not control anything unless your opponent allows you to-you can only fight for it.

  Well, there are two premises in the question itself: ... 2) That 'Controlling the center'is something important.

It is of utmost importance in the opening, as it allows you to completely control the game development. Controlling the center allows you to orient your actions towards the wings without worrying that your opponent can counter-strike in the center-thus usually refuting your plan or at least getting the equal play.

Also, you can open or close the game when you seem fit which usually can decide the game to your favor-not to mention the speed which your pieces get when centralized, since they can reach any part of the board in relatively equal amount of moves, contrary to the pieces posted at the wing.If we have a knight on d4, he can reach both wings at relatively equal amount of moves, but if it is posted on h3 then he needs a lot of moves to reach queen side which sometimes proves fatal.

Also, controlling the center hinders the activity and coordination of the opponents pieces-which enables you to start preparing for an attack or at least to create some serious weaknesses in their position.

In short-controlling the center is of paramount importance from the start to the end of the game-just remember that controlling is not the same as occupying the center.

To be honest, I haven't seen the opening that controls the center-all the modern openings either:

Fight for it.
Divide the control-E.G. White controls d5 and e4 and Black controls d4 and e5, usually by blocking the center, or by exchanging central pawns.
One side "surrenders the center" giving the opponent space advantage, but in return gets huge pressure against that center from the sides or from the distance ( usually light pieces perform the pressure ).

  It appears to me that 'controlling the center' is the least of the benefits of a move like e4 or d4. The fact is that it becomes mandatory to play e4 or d4 if you want to develop both bishops along their long diagonals(c1-h6 diagonal or a6-f1 diagonal). This seems to be the most important benefit of e4/d4 IMO and not 'controlling the center'.

You are almost there-the point of e4/d4 is to decide how will you fight for the center which will directly decide what type of pace will that fight take. Since e4 gives free development of the pieces-but e4 pawn has no initial support-the emphasis in this types of positions is on speed. You must develop your pieces and rely on them to fight for the center. This usually leads to the scenarios described above under 1 and 3, second option being only seen in some variations of French defense and Caro-Kann.

Since White has the advantage of the first move, he is naturally faster, so another benefit of the e4 is the ability for him to play gambits-hoping to be the first one to get the initiative in the center-which he can not achieve without controlling the center.Just the fact that some of the gambits in that link are viable, solid openings can show you just how much the importance of the center control is.

In short-e4 is played to give you fast development of your pieces-which is always used in fight for the center ( see Alekhine's defense, Ruy Lopez among many others ).

On the other hand, d4 is a bit clumsy move for developing pieces ( the queen does not have any good square to be developed ), but d4 pawn has support from the start.

This reduces Blacks options and immediate counter-attack is impossible. This gives White great solidity in the center but slows down his game. Again, the goal is the same-control the center but this time the strategy that implements this idea changes:

Instead of fighting the opponents pieces/pawns, that fight for the center, with your own, you will first occupy the center with pawns-so you can get space advantage.Once you do that you will have the time to finish development. Black, on the other hand, has a limited choice here. He can not counter attack at d4 at once ( 11. ... Nc6 is useless, opposing to 1. ...Nf6 in the Alekhine's defense ), so he usually opts for pressuring White center with his light pieces from distance, and then engineers a flank counter attack. The positions are usually closed, since White blocks center most of the time, but sometimes division of control occurs ( some variations of the Nimzo-Indian defense are a good example ) which results in semi-open games.

To summarize:

Both moves are played with one thing in mind-to fight for the center. The only difference is in the way they implement the fight-with e4 you get speedy development but unstable center which results in a "fast paced" games, yet with d4 you get stable center which slows down the game.

In both cases Black and White fight for the center and the winner of that fight controls the center-which results in immediate advantage for him.

Since chess is a balanced game, if both sides play properly then nobody wins the fight, only one of the 3 scenarios listed above can occur.

  So while it may turn out that 1) e4 and 1) d4 give rise to good games for white I feel it may be more due to the rapid development which these moves allow rather than because these pawns 'control the center'.

Indeed. Just a small adjustment of your observation-quoting you:

So while it may turn out that 1) e4 and 1) d4 give rise to good games for white I feel it may be more due to the ability to beneficially deploy pieces to fight for the control of the center which these moves allow rather than because these pawns 'control the center'.

  Indeed, sometimes, these pawns can be an obstacle for white's own pieces.(I am looking at things from white's perspective but the same argument can be similarly posed from the black player's perspective as well.).

Exactly. The whole point of those moves is to enable other pieces to fight for the center. Which move you choose from those 2 is a matter of preference.

One thing for the end:

You can also fight for the center with light pieces only, making pawn thrusts later-after the position gets clarified and one such example is the Reti opening ( look at Reti's games to see what I exactly mean ).

Check out this section on Wikipedia( Control of the center ) and I think that this article also sheds some valuable light.

If you have further questions leave a comment-I will gladly help.

  Do post your thoughts on this.

You really should avoid discussions-here we strive for a single answer.

Best regards.


Dr. John Nunn vs Irving Chernev's "Logical Chess Move by Move" I have the book "Logical Chess Move by Move" by Irving Chernev and personally I find it to be a great book especially for beginners, but I heard that GM John Nunn has really criticized the book.  This makes me read the book with caution and slight paranoia.  Does Nunn have valid points?

Here is a link from one of Dan Heisman's Novice Nook articles discussing Nunn's criticisms of Chernev's book.

It seems that Nunn (who is undoubtedly a stronger player than Chernev was) is correct in his criticisms of certain instances of analysis in Chernev's book, and also correct in pointing out that Chernev is sometimes too quick to dogmatically conclude an overarching general principle that doesn't properly allow for exceptions. But I don't believe this should cause you to read Chernev's book with caution (at least no more caution or skepticism than one should have when reading anything), and certainly not with paranoia.

The criticisms Nunn directs Chernev's way in Grandmaster Chess Move by Move are worthwhile things to hear for a player who is at an appropriate level to be reading Nunn's book, but the intended audience for that book is quite a bit more advanced than is Chernev's. The fact that Chernev makes certain oversimplifications (and yes, out-and-out mistakes in some places) is a good thing to be discovered at some point in a player's chess development, but this doesn't necessarily mean that Chernev's book, warts and all, cannot be (very!) useful to a beginner. [Consider: an absolute beginner reading Nunn's criticisms of Chernev that you cited wouldn't be able to appreciate the points being made at all: they would sail right over his or her head.]

The saying "One has to know the rules to break them" is applicable here. If you were to try and take every word in Chernev's book as gospel for the rest of your chess career, you would indeed be leading yourself astray. The same would be true if you tried to dogmatically follow, say, "knights should be developed before bishops" or similar overly general advice which is routinely thrown at novices. That doesn't mean that that kind of advice doesn't serve a useful purpose by giving newcomers to the game some first, rough guidelines to start learning from. I think the same can be said for Chernev's work; after all, it's not for nothing that this instructional book from 1957 is still topical today.


Is there any important thing to note from this game? [FEN ""]

1. c4 c6 2. d4 d5 3. Nc3 Nf6 4. e3 e6 5. Nf3 Nbd7 6. Bd3 Be7 7. O-O O-O 8. b3 b6 9. Qe2 Bb7 10. Rd1 Qc7 11. Bb2 Rad8 12. Rac1 Qb8 13. h3 Bd6 14. e4 dxe4 15. Nxe4 Bf4 16. Nxf6+ Nxf6 17. Rb1 c5 18. dxc5 bxc5 19. Ne5 Qa8 20. Ng4 Nxg4 21. Qxg4 Bh6 22. Bf6 Rd7 23. Bf1 Qc8 24. Rxd7 Qxd7 25. Rd1 Qc7 26. Bg5 Bxg5 27. Qxg5 h6 28. Qd2 Be4 29. Qd7 Rc8 30. f3 Bc2 31. Rd2 Bb1 32. Qxc7 Rxc7 33. a3 Rb7 34. Rb2 Bg6 35. b4 Kf8 36. Kf2 Ke7 37. Ke3 Kd7 38. Be2 Kc7 39. b5 Rb6 40. a4 f6 41. a5

I was analyzed this game, but sadly couldn't find anything to learn from it. Did I miss something, or is this just a simple game as it appears to be?

Even simple games are full of possibilities. If you want to learn, you have to investigate these possibilities. Ideally without an engine.
Some lines of investigation:
What happens after 23.Bxh7 and Rxd7?
What about 23.b4 cb 24.Bxh7?
How does 26.Rd3 with the idea of Rg3 pan out?
How does 31.Qxc7 Rxc7 32.Rd8+ differ from the game?


How can Elo be unofficially estimated? @user1657 has given an interesting answer to a question of @ArghyaChakraborty. He says that the Android app called "Analyze your games" can estimate the user's Elo strength.

How would it do that?

You're probably not going to offer me a master's thesis on the mathematics of Elo-rating estimation here, but I'd be interested in a vague outline of the mathematics, or of the technique, if you happen to know it.

Or maybe you'll close this question as off-topic. It's kind of on the borderline, I'll admit. But, still, a computer estimating your chess strength, so that you know whether you're ready to take Karjakin's seat against Carlsen? That's pretty cool.

Generally the approach to estimate an Elo rating directly from the games, is to calculate the accuracy of the moves compared to the best move given by an engine.

There is a correlation between accuracy and playing strength, which can be used to calculate an Elo estimate from the accuracy. This idea is laid out in this paper by Ken Regan.


Learning my favorite grandmaster games by heart I am novice with average of 1000 -1500 elo.

If I start learning games played by grandmasters by heart, as in memorizing them, does it help me improve my chess skill, or it is a useless waste of time?

Also, I’m not talking about just random grandmaster games, but games from grandmasters with style that I like for a particular reason, such as their attacking style for example

This doesn’t mean learning games with a deep analysis as to why this move was made (because of my low rating), but learning with a possible chance to learn typical/mini combinations.

Any suggestions?

It won't help much. You won't understand why they are choosing the moves they are making. The easiest and fastest way to improve is to go to your local chess club. They will pair you with opponents of your skill level. The better players will help you.


Are there any books pamphlets or articles on how to train to play at GM level? CL&R had an article about how Fischer trained at a spa in the Adirondacks for an upcoming match.

One thing he did was swim and also hold his breath for as long as he could.  Not sure that latter was good.

Recent reports have Caruana and Chirila going for long runs, playing tennis, basketball, and also swimming.

Anand does 2 hours of cardio each night to help stop him from dreaming about chess.

Carlsen went to the Olympic center with his father and they had him change his diet.  Less orange juice with sugar and substitute a mix of chocolate/regular milk.   He also trained by skiing and hired a personal chef to balance his carbs protein, and calcium.

Carlsen even optimized his sitting position.

Further he reduced his schedule to about 7 tournaments a year instead of about 13.  And took time off after each to recuperate.

So GMs do many things other than study chess.  Are there any books or good articles prescribing what would be best for training our bodies to play tournaments not just learning chess more itself.

I do not think that there are any books devoted specifically to this topic, probably since the subject is not big enough, and most physical training is covered by books devoted to that subject, in general (not with chess in mind). The topic may be touched upon in other books.

For example, probably first to take a modern approach to training the body was Kasparov, and his trainer goes into that in his two-volume series on Kasparov's development. In fact, on the cover of volume 2, you can see a picture of them running. Even so, the book does not spend a lot of time on this aspect as most people are more concerned with the purely chess aspects of his training.

Coaching Kasparov, Year by Year and Move by Move, Volume I + 2 by Alexander Nikitin.

I believe that Botvinnik was probably the first to espouse the benefits of physical training SERIOUSLY, and I have seen this written about in passing, but again, there was not enough material for a whole book.

Here is a nice article on Botvinnik on "Sports Illustrated". It discusses his physical training a little.

Here is another webpage that discusses the training activities of various modern GMs.

Here is another very good article on the subject. "How physical activity can help you play chess better?"


How to play this endgame without consulting the tablebases Recently I got this position in a game I played as Black with White to move.
 [FEN "8/8/8/R6p/4KP1P/6P1/pr6/1k6 w - - 0 1"]

Here, White captured with the move 1.Rxa2. It turns out that 1... Kxa2 is winning while 1... Rxa2 loses. Is there any way to see that Kxa2 must be played instead of Rxa2 without turning to the endgame tablebases? How do you judge such endgames?

In positions where the side with the Rook is trying to hold back the passed pawns it is often critical how quickly the King can scramble back to base, because the Rook will usually be easy. If for example the King must reach g8, then ..Kxa2 leaves the King with one rank less to cross and therefore (other things being equal) will save a tempo. Therefore my instinct would tend toward ..Kxa2 rather than ..Rxa2, even before attempting any analysis. The question whether other things truly are equal is the reason why endings in general need a lot of calculation. In this case they probably are.
However, why did White take the pawn before it promoted? 1.f5 waiting for 1..a1=Q 2. Rxa1 Kxa1. White would then be two tempi up compared to the game. He made Black spend a move on promoting, and also ensured that the Black King would have to cross all eight ranks.


Swiss system pairing algorithm stuck I'm building a Swiss System algorithm and have the following scenario.
10 participants.
8 rounds are to be played.
Generating round 8, I have three players that haven't played each other.
These three players have all played the same other 7 players in the previous 7 rounds of the tournament.
For round 8 I can pair two of the three players together and the third wouldn't have anyone to play with, since everyone can only play everyone else once?
Is this situation logically possible?

Is this situation logically possible?

Certainly.

This is one of the known problems with using Swiss pairing when the number of rounds is close to the number of players. It is called "jamming". There is no simple software solution. For a serious tournament you would not use Swiss pairing when (Number of players) < (number of rounds + 2). Remember a round-robin tournament has (number of players - 1) rounds for an even number of players.

In real life what the arbiter does is check for potential jamming when close to the limit, particularly if there is a group of players who have only played each other. This is a warning sign that jamming is a possibility. In your case in round 7 the arbiter would check the pairing before publishing as follows:

Set all the results to draws and pair the next round. If this works there will be no jamming in this round and the arbiter would rollback the draws he entered to the correct round and publish the pairings. If jamming does occur then he would rollback and manually change the pairings to break up the jammed group of players and then check by setting all draws as before.


How are the scores decided in Chess? Consider the following pictures:

I would like to understand the following:

My understanding is that it depends on the opponent's move against our move. Am I right?
What is the minimum and maximum range of the score?
When one can achieve the maximum score at very first move?
What is the use of the score?

(Sorry for asking very basic questions. Newbie for the Chess stuff).

Those aren't scores; there are just three possible scores in chess: White wins, Black wins, and draw.

Those are evaluations of the chess engine; a score of +0.62 means the engine thinks White's position is better by 0.62 pawns. A negative score would mean Black is better. On professional level, a score of 1.5 pawns is in most positions decisive, i.e. enough to win the game. However, weak moves by the players will change the evaluation.

The maximum and minimum score depends on the chess engine you're using. If you play the game till checkmate, you will see that the scores will get larger (either more positive or more negative) until you see something like +#8 which means White can mate in 8 moves.


Is 80 points FIDE equivalent to twice as good a player? I read somewhere that if you're around 80 points better than another player, statistically you should get around twice as many points against the same opposition. This impressed me because it's not how we generally think about ratings. I worked out that Magnus Carlsen is about 64 times the player I am, which sounds about right.

My question is, can anyone verify this using the mathematics of the Elo system?

This can't be true. I (rated ~1900) expect to score 100% against a 1000 player. I don't think a 1980 rated user is able to score 200% against the same opposition.

In table 8.1b in the FIDE rating regulations, you'll find the expected scores corresponding to a rating difference. A rating difference of 80 corresponds to an expected score of 0.61, which is much lower than twice the 0.5 expected score for equally rated players.

The only point in the table where a rating difference of 80 corresponds to a doubled expected score is at the very end. Against opposition rated 500 points higher than you, your expected score is 0.04; against opposition rated 580 points higher it's only 0.02. The expected score formula is explained on Wikipedia:

  If Player A has a rating of RA and Player B a rating of RB, the exact formula (using the logistic curve) for the expected score of Player A is

  EA = 1 / (1 + 10 (RB - RA) / 400)


Is there any other notation system other than algebraic notation? Other than the current coordinate notations used in chess, are there any other notations that anybody knows about? I am looking for anything that does not employ the coordinate system like naming all squares or any other sharp ideas.

Other than the algebraic nomenclature:
Two off the top of my head are
Correspondence chess used 1:1 to 8:8 to label the squares.
Descriptive notation predated algebraic: 1. P-K4 P-K4 2. KN-B3 QN-B3 and so on.


Chess challenge #9: Can you solve it in less than 5 minutes? Today I remembered this position that I saw a few months ago in a tweet by Sergey Karjakin:

[fen "2k5/8/8/BQ6/4K3/8/8/8 w - - 0 1"]

It seemed very easy to me because there are just 4 pieces left but it was much more difficult than I expected. Sergey was asked to solve it in less than five minutes as part of a bet (which he won).  White to play and mate in 3. Can you also solve it in less than 5 minutes? :)

Got it barely under the mark.  Not sure if it helped or hurt that I knew the mate-in-2 with a similar position (move the Ke4 to f5).

   1 Qb2!! Kd7 2 Qe5! Kc8/Kc6 3 Qc7/Qd5#!

Spoiler for mate in 2 (Kf5 Qb5 Ba5 / Kc8):

   1 Qb3! Kd7 2 Qe6#!