Francesco di Castellvi vs Narciso Vinyoles

[Event "?"]
[Site "?"]
[Date "1475"]
[Round "?"]
[White "Don Francí de Castellví(mars aka love)"]
[Black "Narcís Vinyoles(venus aka glory)"]
[Result "white"]
[FEN "?"]
[Time "?"]
[TimeControl "?"]

1. e4 d5 2. exd5 Qd5 3. Nc3 Qd8 4. Bc4 Nf6 5. Nf3 Bg4 6. h3 Bf3 7. Qf3 e6 8. Qb7 Nbd7 9. Nb5 Rc8 10. Na7 Nb6 11. Nc8 Nc8 12. d4 Nd6 13. Bb5 Nb5 14. Qb5 Nd7 15. d5 exd5 16. Be3 Bd6 17. Rd1 Qf6 18. Rd5 Qg6 19. Bf4 Bf4 20. Qd7 Kf8 21. Qd8#

This is derived from the poem which you can read here. I found this while watching this youtube channel.

At move 19 here I can see the three piece attack you were talking about. Here the bishop gets sacrificed for getting a checkmate. This the oldest usage of it that you'll find where the rules followed are the same as today.

Closest thing i could find was this sentence:

   "3 Piece Rule Compiled by notyetagm  --*-- You need three pieces to
  checkmate the enemy king, one to sacrifice and two to deliver mate. Of
  course more is better. :-)"

Rule: one of a set of explicit or understood regulations or principles governing conduct or procedure within a particular area of activity. It should be absolute(a value or principle which is regarded as universally valid or which may be viewed without relation to other things)

But we know that it is possible to Checkmate your opponent using less than 3 pieces.
Example: For checkmate using single piece => Back rank checkmate or a smothered checkmate
For checkmate with 2 piece there is => classic queen rook checkmate or Diagonal checkmate,etc

Hence, it is not applicable everywhere and thus it isn't a rule (you shouldn't considered it either).
"if you have three pieces or more in the attack you can sacrifice without thinking!" But this is a line that works a lot of time. So the question arises what is this? It's just a strategy or if you wanna be specific its a attack strategy or even a checkmate strategy in cases.

You can even generalize this as "trade off when you have more number of attacking pieces that defending pieces". It actually establishes the basics of our chess today, that might not be fruitful in all the cases. As there is one and only one goal in chess , that is to defeat your opponent and obtain a victory.
So, Apply it all you want but make sure to win. Or at least its application should be fruitful to you and not your opponent.

As to my final answer to you, it isn't a rule it's a strategy and like other strategy's there is a very strong likely hood that someone played it before it got recognized by some name. As to oldest usage its  Mars vs Venus,1475 if you'll consider this. So, regarding who and when, it's something i feel that has evolved with time along with the modern chess.

Thank you!


How big is the "opening book" of a typical tournament player

It depends.

Myself I play at a 1900 FIDE level and I have practically never studied openings!

Take as an example two players of my club rated 2250 FIDE:

Player A: theory enthusiastic: This player not only have a repertory close to an IM, but he went to a pub before each game to
study possible development of the games taking in consider what
openings his rival played.
Player B: tactics enthusiastic: This player do not study more theory and just played for fun at the club. He of course know some
basis because to reach that level you need to survive against every
+2000 the first ten moves, but he never prepared any game and uses to fall in second non book lines at the first moves.

Anyhow at a titled level everybody has a repertory. But also at this level there are some masters that know very deep lines of a huge repertory: more than fifty openings with more than ten lines on each one, to make a rude calculation, and others that just do not fall in ambushes, but as player B of my club can fall in non book lines to make think their opponents.


Here's my take on this question, since I find the other two answers lacking actual examples.
Knight promotion
In the situation below black has been trying to prevent white from promoting the pawn (white has earlier given up his rook for a black pawn). White manages to promote, but only one of the promotions secures a (tablebase) draw.
[white "Alexander Evdokimov"]
[black "Evgeni Ellinovich Sveshnikov"]
[event "56th Russian Championships, 2003"]
[fen "8/r3KP2/8/4k3/8/8/8/8 w - - 0 1"]

1.Ke8 Ke6 2. f8=N+! {2. ... Ra8+ otherwise} 1/2-1/2

Here, white underpromotes to avoid stalemate.
[white "Iroda Khamrakulova"]
[black "Ekaterina Ubiennykh"]
[event "WJun Women, 2001"]
[fen "6r1/k1P5/P7/1K1R4/8/8/8/8 w - - 0 1"]

1. Rd8 {according to tablebases, Rd7 wins faster} Rxd8 {again, there are slower ways for black to lose} 2. cxd8=N! {stalemate if rook or queen is promoted, a draw if a bishop (wrong corner)} 1-0

In the situation below, white has just played Qg3. Black underpromotes to gain a tempo, as white threatens checkmate and fork rival king and queen.
[white "Zvonimir Mestrovic"]
[black "Svetozar Gligoric"]
[event "Hastings, 1971/72"]
[fen "7k/1p2Npbp/8/2P5/1P1r4/3b2QP/3q1pPK/2RB4 b - - 0 1"]

1. f1=N+! 0-1

In the position below, white underpromotes to deliver a checkmate.
[white "William Strum"]
[black "John McManus"]
[event "Eastern Open, 1997"]
[fen "8/p3R2P/1p4k1/6p1/2rB2KR/P1r5/8/8 w - - 0 1"]

1. h8=N+ 1-0

Last, but not least, a very neat opening trap. Black undepromotes to gain a tempo and subsequently win the white queen.
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1. d4 d5 2. c4 e5 3. dxe5 d4 4. e3 Bb4+ 5. Bd2 dxe3 6. Bxb4 exf2+ 7. Ke2 fxg1=N+ 8. Rxg1 Bg4+ 0-1

Rook promotion
Arguably, less spectacular than knight underpromotions. One would promote to a rook in order to avoid a stalemate (otherwise, anything a rook can do, a queen also can). Two examples from endgames below.
[fen "6k1/6P1/5K2/8/8/6P1/8/8 w - - 0 1"]

1. g4 Kh7 2. Kf7 Kh6 3. g8=R! {stalemate in case of queen promotion. Knight promotion would also win, but would take longer} 1-0

.
[fen "4r3/5RPk/5K2/8/8/8/8/8 w - - 0 1"]

1. Rf8 Rxf8 2. gxf8=R {stalemate in case of queen promotion, unable to win if promoting to a minor piece} 1-0

Bishop promotion
These are the rarest of the bunch. Usually would be to avoid a stalemate, or some other extraordinary situations, since otherwise, anything a bishop can do, a queen also can. First, a classic.
[fen "4Q3/Pq4pk/5p1p/5P1K/6PP/8/8/8 w - - 0 1"]

1. a8=B! {promoting to rook or queen runs into Qf7+ and stalemate} 1-0

Another endgame.
[fen "8/8/5b2/8/K7/4N3/kp6/8 w - - 0 1"]

1. Nd1 b1=B! {Nc3+ if promoting to rook or queen - draw} 0-1

Lastly, this amazing position.
[fen "1r5K/6PP/8/8/8/1k4q1/6P1/8 w - - 0 1"]

1. g8=B+! {black must move the king and it is a stalemate} Kb4 (1... Rxg8+ 2. hxg8=Q+ Qxg8+ 3. Kxg8 {and the g2 pawn will inevitably promote - white wins}) 1/2-1/2

Sources for these and many more examples
http://timkr.home.xs4all.nl/chess2/minor.htm
http://www.chessgames.com/perl/chesscollection?cid=1000028


How do I decide what color squares to place my pawns on?

This is a very complicated subject since there are a lot of other factors that come into play so I will give some examples, but there are no general rules that apply in all circumstances.

First, let's take this common opening structure from the Slav. In this equal position, black wanted in imbalance, and traded off the light-squared bishop, so in order to keep some control of the light squares, he played e6. In addition to wanting to keep some control of the light squares, it also does not contribute to potentially making the Bf8 bad later.

 [FEN ""]

 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. e3 Bg4 5. h3 Bxf3 6. Qxf3 e6

Next, lets talk about an endgame position with a bishop versus a knight or a same-colored bishop. In general, you do not want to put pawns on the same color of the bishop as that makes the bishop "bad". A bad bishop lacks scope due to its own pawns, and in addition, it often leads to zugswang.

Here is a position that is equal, but one bad move putting a pawn on the same color as the bishop, and it is over. In addition to limiting the Bf8, it weakened the light squares, and in many positions, it might have given white another target to attack.

 [FEN "5b2/3kpp2/1p1p4/5P2/3K2P1/1PP3B1/8/8 b - - 0 0"]

 1... f6 $4 2. Kd5 Bh6 3. Bf2 Kc7 4. c4 Bf4 5. Ke6 Kd8 6. Bxb6+

An exception might be if all the pawns are compact, and you want a draw. Consider this position where black plays e5, but then can put the king on the unassailable e6 square. Even losing f6 here would lead to a draw.

 [FEN "8/4k3/4pp2/8/4P2B/2b2P2/8/5K2 b - - 0 1"]

 1... e5 2. Ke2 Ke6

Next, let's talk about opposite colored bishops. In general, if you are winning, you want your pawns on the opposite color as your bishop, but often if you are worse, it is fine to put the pawns on the same color as the bishop since they cannot be attacked by two pieces.

Note in this ending how white advances the pawns, but always only when they can both stay on the light squares.

 [FEN "8/8/3k4/1b6/3PP3/4K3/8/4B3 w - - 0 0"]

 1. Bb4+ Ke6 2. d5+ Ke5 3. Bc3+ Kd6 4. Kd4 Be2 5. e5+ Kd7 6. e6+ Ke7 7. Ke5 Kd8 8. d6 Bb5 9. Ba5+ Ke8 10. Kd5 Ba4 11. Kc5 Kf8 12. d7 {and queens}

This last one is an example of the latter type discussed above. Black is worse, and has multiple ways to draw, but the immediate f5 makes it virtually impossible for white to win, let alone attack any of the black pawns. At best, they will trade some, and black will sacrifice the bishop for the last pawn.

 [FEN "8/4kp2/2b1p3/8/8/4B1P1/3KPP2/8 b - - 0 1"]

 1... f5

Summing up, and these are VERY general rules, most of the time, you want the pawns on the opposite color of your bishop, or if you are going to trade a bishop, trade the one that is of the same color as most of your pawns. Occasionally, you may find positions where you are worse, but the bishop can defend everything well if the pawns are on the same color, especially in opposite-colored-bishop endings, but if they are not opposite colored, you must look out for positions that are ripe for zugswang, so be VERY careful breaking the first rule about putting them opposite your bishop.

Lastly, in opposite-colored-bishop endings, if you are winning, keep them on the opposite color of your bishop, or they will be easily blockaded, but if you are worse, and trying to draw, often you can create a fortress by putting them on the same color as the bishop.


Here's one way:

Use the Rook to restrict the opponent's King to one part of the board.
Use your King to gain the opposition (Kings facing with one space between them, and it being your move)
Use the Rook to take a rank (or file, as appropriate) from the opponent's King.
Repeat until checkmate.

[Title "Checkmate with K+R vs K"]
[FEN "8/8/8/3k4/8/8/6K1/R7 w - - 0 1"]

1. Ra4 {Now the king can't access half of the board.} Kc5 {He chases the Rook. Don't get fixated and let him take it! #guilty} 2. Rh4 {Keep the Rook away from the enemy King} Kd5 {The opponent will not want to leave the the 5th rank.} 3. Kg3 {This move is actually a little tricky, but the concept is key to quickly winning this ending. We must not allow the opponent to gain the 'opposition'. Whenever there is one space between the two Kings and they are lined up (even diagonally), that is, when they _oppose_ one another, the player on move has the advantage. Thus if we played Kf3, Black would have the opposition and we'd waste moves.} Ke5 {Keeping in the center, the best defense.} 4. Kf3 {Note this position - your King between your Rook and the enemy King. Now the enemy has 2 choices, charge or run. Might as well charge...} Kf5 5. Rh5+ {Absolutely fundamental here is that you gained the opposition (the Kings had one space between them and it was your move). In this position, you take the row away from the opponent's King.  This is what this checkmate technique is all about.}  Kg6 {Never give up. Maybe White will make a careless error...} 6. Ra5 {Nope. The Rook runs.} Kf6 {chases!}
7.Ke4 {Now if the enemy King chases, White gains the opposition again...} Ke6 (7...Ke7? {when defending, do not surrender space} 8. Ra6! {Gobble that rank!}) 8. Ra6+ Kf7 {Black knows he's doomed.} 9. Ke5 {Other moves allow Black to get the opposition. Do not allow it.} Kg7 {He runs because he knows what happens if he goes the other way.} 10. Kf5 Kh7 11. Kg5 {almost there...} Kg7 {what else??} 12.Ra7+ {Forces the King back} Kh8 {Kf8 is better but I have to go to work!} 13. Kg6 {will gain the opposition next turn. Not Kh6? which allows the king to escape to g8. Then you'd have to chase him to the other side of the rank. Go ahead and try it, it's annoying.} Kg8 14. Ra8#

One thing about your Rook when checkmating like this - never give up a row once you take it. Never loosen your grasp.

Another thing is that your King should be between the opponent's King and your Rook. If he chases your Rook anyway, you'll get him in opposition and force him back. If he does not chase your Rook, then he'll run out of room to run and you'll gain the opposition. Sometimes, you'll need to move your Rook one square to 'waste' a move. If you do, don't surrender the rank! Keep the king contained. See the 2nd diagram.

You can use the opposition in lots of endgame positions to force your opponent to make a move he does not like. Learn it, love it.

Per the note above. In this case it is White's move. But the natural Kh5 and Kf5 give Black the opposition which means the game will be extended. The horrid Kg6 allows the King to slip the noose. So White needs to put black in Zugswang (which means to make him make a bad move.)

[TITLE "It Happens."]
[FEN "8/7k/R7/6K1/8/8/8/8 w - - 0 1"]

1. Rb6 {Now Black has no good moves.} Kg7 2. Rb7+ {There we go, we're back on track.}


Eating and drinking before and during a game

I have played tennis and chess both quite seriously for several years and my preparation towards a game when it comes to food, is basically the same. I try to eat around 4 hours before the game, some pasta with a light sauce or no sauce at all, avoid red meats 24 hours prior to the game and rink only water the day of the game. If I am to start in the morning then a light breakfast. In general I would rather play with a non-full stomach but here's the "secret", I do eat a chocolate bar at the beginning of my chess games and have a bottle of water at hand, this helps me greatly to keep my blood pressure normal, and able to focus on the game without feeling hungry even after 4 or 5 hours of play.

I guess my advice is to know what works for you, I have seen that avoiding heavy meals is generally good for performance but if you (like me) need an extra kick, pick up an energy bar of some sort (I would avoid coffee because of the possibility of needing to go to the toilet at a bad time).

All the best and hope it helps! :)


What is a “dual” in chess problems, such as the Babson task?

A dual is an alternate solution, other than the intended one, after the first move of a problem or study. If it happens on the first move, the problem or study is called cooked instead.

  dual

  Ideally, White should have only one move at each juncture that solves a problem. If White has an alternative at any stage other than the first move, this is a dual. A dual is not as serious a flaw as a cook, and in minor lines, duals may be permissible (opinions differ on this point). Some problems make a virtue out of dual avoidance – of two apparently equivalent white moves, only one works.

(source: Wikipedia)


About how to win a pawn by applying pressure-Looking for examples

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

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

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

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

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


Studies that have been cooked by computers

I don't know how famous it is, but here is a study shown to be incorrect by computers:
 [Title "J. van Reek, 1987. White to play and draw."]
 [FEN "8/5n2/5N2/3K4/8/3p4/Rn6/1k6 w - - 0 1"]

 1. Ra3 d2 2. Rd3 Nxd3 3. Ne4 d1=N! 4. Ke6 Nd8+ (4... Nh6!) 5. Kd7 Nb7 6. Kc6 Na5+ 7. Kb5 Nb3 8. Nc3+ Nxc3+ 9. Kc4 Kc2 1/2-1/2

The intended solution is given in the diagram. It has a very nice stalemate finish.
Unfortunately black can play 4... Nh6!, and according to the tablebases there is a win for black in 39 moves.
So three knights can win against one. Having to play this ending would give me nightmares!


How can one easily learn chess board coordinates?

Some websites offer "coordinate drills". I'm not sure how effective they are for learning, but you can certainly give them a try. I found it to be surprisingly entertaining to try to beat my personal record number of coordinates per minute (or whatever the time limit is). Here are the two I know of, but maybe there are others (and maybe there are apps, as well):

https://www.chess.com/vision

https://lichess.org/training/coordinate

Personally I've found that studying openings (and to a certain extent, checkmate patterns) helps learn coordinates because you start associating coordinates with certain moves, which gives each square its own "personality". For example, c4 is not just c4 anymore; it is the square where the bishop goes in the Italian game, or where the pawn goes in the queen's gambit.


1. e4 e5 2. f4 d5 is known as the Falkbeer Countergambit.

However, 3.fxe5?? is not a variation but a blunder. As Wikipedia explains, you will either lose material after  3...Qh4+, 4.g3 Qxe4+ (due to a fork between the King and the Rook), or expose your King to the black pieces after 3...Qh4+,  4.Ke2 Qxe4+ 5.Kf2 Bc5+.

I am not aware of a name for 1. e4 e5 2. f4 d5 3. exd5 e4 4. d3 Nf6 5. dxe4. Not every opening variation has a name.


What is a good line against the King's Indian Defense for blitz play?

I think a good way of preventing Black's kingside play is the Makogonov (or Makagonov) variation:

[fen ""]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.h3

This is more strategical than tactical, and most of the times prevents Black's ..f5 by playing g4 with White! Not to attack, but to restrain.

After 5..0-0 you can choose:

either a setup with 6.Nf3,
or first develop the queen's bishop (6.Bg5), keeping the option open of playing Nf3 or Nge2.

For the first setup, reply all games played by Chessexplained, he has a tremendous score with this variation, explaining plans while playing: https://www.youtube.com/user/Chessexplained/search?query=makogonov. I especially liked

https://www.youtube.com/watch?v=wqNBR4wejCU (playing on two wings),
https://www.youtube.com/watch?v=ca0tTOOhb6A (explaining some theoretical ideas) and
https://www.youtube.com/watch?v=cJk-NejbiHQ.

For the second, more flexible, setup, read John Watson's "A strategic opening repertoire for White".

Good luck!


Suggest a line for a player who does not want to be dragged into the Sicilian

You could transpose to the Botvinnik English System:

[FEN ""]

1. e4 c5 2. c4

Because it is a system opening, you usually put your pieces on the same squares regardless of what Black does. For example:

[FEN ""]

1. e4 c5 2. c4 Nc6 3. Nc3 g6 4. g3 Bg7 5. Bg2 Nf6 6. Nge2 O-O 7. O-O d6 8. d3

The usual piece placements are:

Fianchettoed kingside castle
Knights on c3 and e2
Queen on d2 and bishop on e3
A rook off the a1-h8 diagonal, e.g. on b1

Evaluating this opening we see that:

It's a system opening, so it is easy to learn. But it doesn't give the best chances to win
The Botvinnik Triangle, pawns on c4, d3 and e4, allow White to play on any sector of the board. For example: breaking with d4, attacking with f4 or gaining space with b4
White has a hole on d4, which might be quite tender

See also the YouTube video Chess Opening for White: Botvinnik-English System against the Sicilian Defence.


What is the book containing this puzzle with an unexpected answer?

Well, here's a link that contains the game, probably.  I'd guess it's example #1.  This may give you more information for your research.


Are all KQvK positions winnable if it's not stalemate and Black can't capture on current move?

Yes, all KQvK positions are won under these conditions (no stalemate, no capture). The same holds for KRvK.

The only possibilities for such basic endgames not to be won under your conditions would be:

a piece has too few square available and can be captured by the black king (not immediately but in the next move)
white on the move cannot avoid stalemate (or material loss)

An example for the first case (black to move):

[FEN "7N/8/8/4k3/8/8/6K1/7B b - - 0 1"]

the second case (white to move) looks like this (to avoid stalemate, white's king has to go to the d file when after Kb7, black wins the bishop or knight):

[FEN "kB6/2K5/N7/8/8/8/8/8 w - - 0 1"]

However with the KQvK and KRvK, the queen/rook always have enough space to avoid these problems.


What are some common statistical analyses we can run on many games (~20k games)?

You can find posistional themes and other interesting info from SCIDvsPC software. Sample of output-

4.3 Positional Themes

Frequency of themes in the first 20 moves of each game:
Same-side castling:             73%    White Isolated Queen Pawn:       8%
Opposite castling:               8%    Black Isolated Queen Pawn:       8%
Kingside pawn storm:            15%    White Pawn on 5/6/7th rank:     52%
Queens exchanged:               40%    Black Pawn on 2/3/4th rank:     34%
Only one side has Bishop pair:   6%    Open c/d/e file:                50%

I had answered the same on this question: Chess Olympiad statistics


Why should I expect that black moves Rxd2 after I move Bxe3 in this puzzle?

The point here is that none of Black's possible responses to 1. Bxd6 prevent 2. Qxf7#. Blocking with the rook or queen leaves it pinned, and blocking with the knight or bishop or capturing with the queen means that the black queen is no longer attacking f7. The puzzle just gives an example second move, with the implication that it doesn't matter which one they pick. (The fact that this example involves a pin makes 2. Qxf7 a little bit less obvious, so that's probably the motivation for that choice.)


I have played against this opening a lot, sometimes in bullet sometimes in blitz games, and even in casual ones without the clock. some of the opponents were strong candidate masters and sometimes a FIDE master would use it.

The easiest defense for me is 1...e5 and on 2.Bb2 to simply take on b4. This has several benefits:

White is behind in development ( plays twice with the bishop );
Black hinders White's fight for the center by keeping bishop on a5-e1 diagonal. This is very effective method that simply squelches any initiative White has. He may be equal in the resulting tabya but that is all he gets, and frankly, I believe Black has an easier game;
Black gets half-open e-file which is very useful, since he will play ...d5 and ...Re8 at some point, so he can count on ...d4 push to generate initiative;
Being behind in development and restrained in center, White can't really use b-file;
Since Black has development advantage, the opening of the game benefits him ( ...d4 push mentioned above is useful for this );
All of the Black pieces can acquire best squares ( knights on c6 and f6, bishops on b4 and g4 );
Black has no pawn weaknesses, nor weak pieces, while White has weak pawn at a2;

That is why I would advise you the above approach when battling the Sokolsky attack ( known also as Polish opening or Orangutan ). I have looked into Fritz opening database and found the lines I think give good game for Black in the easiest way ( I have added multiple hoices for Black so you can have a wider choice ). I am going to present them in the below diagram and will explain typical positions and plans afterwards.

[Title "Recommended theory for Sokolsky attack"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.b4 e5 2.Bb2 ( 2.a3 d5 3.Bb2 ( 3.e3 Nf6 4.Bb2 Bd6 5.Nf3 ( 5.c4 c6 6.Nf3 Qe7 7.Nc3 a6 ) 5...Qe7 6.c4 c6 7.Nc3 a6 ) 3...Bd6 4.e3 ( 4.Nf3 Qe7 5.e3 Nf6 6.c4 c6 7.Nc3 a6 ) ( 4.f4 exf4 5.Bxg7 Qh4+ 6.g3 fxg3 7.Bg2 gxh2+ 8.Kf1 Nf6 9.Nf3 ( 9.Bxh8 Ne4 10.Bxe4 dxe4 ) 9...Qg3 10.Bxf6 ( 10.Bxh8 Bh3 ) 10...Rg8 11.Rxh2 Qg6 12.Be5 Bxe5 13.Nxe5 Qf6+ 14.Kg1 Qxe5 ) 4...Nf6 5.Nf3 ( 5.c4 c6 6.Nf3 Qe7 7.Nc3 a6 ) 5...Qe7 6.c4 c6 7.Nc3 a6 ) ( 2.b5 d5 3.Bb2 Bd6 4.e3 ( 4.Nf3 Qe7 ) ( 4.f4 exf4 5.Bxg7 Qh4+ 6.g3 fxg3 7.Bg2 gxh2+ 8.Kf1 Nf6 9.Nf3 ( 9.Bxh8 Ne4 10.Bxe4 dxe4 ) 9...Qg3 10.Bxf6 ( 10.Bxh8 Bh3 ) 10...Rg8 11.Rxh2 Qg6 12.Be5 Bxe5 13.Nxe5 Qf6+ 14.Kg1 Qxe5 ) 4...Nf6 ) 2...Bxb4 3.Bxe5 Nf6 4.c4 ( 4.c3 Be7 ) ( 4.Nf3 O-O 5.e3 d5 ) 4...O-O 5.Nf3 ( 5.e3 d5 6.cxd5 ( 6.Nf3 c5 7.cxd5 Nxd5 8.Be2 Nc6 9.Bb2 Bf5 ) ( 6.Qb3 c5 7.a3 Ba5 8.cxd5 Nxd5 9.Bc4 Nb6 10.Be2 Nc6 11.Bb2 Be6 ) ( 6.a3 Ba5 7.cxd5 Nxd5 ) 6...Nxd5 7.Nf3 Re8 ( 7...Be7 8.a3 c5 9.Be2 Nc6 10.Bb2 b6 11.O-O Bb7 ) 8.Bb2 ( 8.Be2 Rxe5 9.Nxe5 Qf6 10.f4 Nxe3 11.Qb3 Nxg2+ 12.Kd1 Nxf4 13.Nxf7 Qxf7 14.Bc4 Be6 15.Bxe6 Nxe6 ) 8...Be7 ) 5...Nc6 6. Bb2 d5 7. cxd5 Nxd5

OK, now you have thorough coverage of your repertoire with Black. I have tried to keep the number of lines to minimum, but all relevant White replies had to be covered. It is time to explain the ideas and plans in each separate position for Black:

[Title "White takes pawn at e5, Black takes pawn on b4"]
[fen "r1bq1rk1/ppp2ppp/2n5/3n4/1b6/5N2/PB1PPPPP/RN1QKB1R w KQ - 0 8"]

In the above position Black has no weak pieces, he is not cramped and has development advantage. White on the other hand does have central pawn majority but he can't utilize it to gain initiative. The best he can do is e3 so he can safely finish development. Notice the tremendous pressure Bb4+ Nd5 exert on the White position by pressuring the dark squares ( c3 and the entire a5-e1 diagonal! ). This is the key idea of Black's defense in this, and similar positions -> to control a5-e1 diagonal and the dark squares. Black is more than fine here and simply playing natural moves should give you satisfactory position. It is White who fights for equality here.

[Title "Tremendous exchange sacrifice for Black"]
[fen "rn4k1/ppp2qpp/4n3/8/1b6/1Q6/P2P3P/RN1K3R w - - 0 16"]

This is one of the variations from the above diagram that is most complex but is easy to play with Black. Black has sacrificed the rook for a knight, bishop, two pawns and exposed White king. The compensation is more than enough and Black has a winning position in my opinion. Just develop Nb8 and do not be afraid of d4, threatening to fork the knights with d5, because you have ...Rd8! which pins the pawn and gives decisive initiative. White can't survive because of his exposed king and lag in development. Again, you are fine.

[Title "White plays the weak f4 attack"]
[fen ""]

1.b4 e5 2.a3 d5 3.Bb2 Bd6 4.f4 exf4 5.Bxg7 Qh4+ 6.g3 fxg3 7.Bg2 gxh2+ 8.Kf1 Nf6 9.Nf3 ( 9.Bxh8 Ne4 10.Bxe4 dxe4-+ ) 9...Qg3 10.Bxf6 ( 10.Bxh8 Bh3-+ 11.Rxh2 $8 Ng4 ) 10...Rg8 11.Rxh2 Qg6 12.Be5 Bxe5 13.Nxe5 Qf6+ 14.Kg1 Qxe5

The whole point of f4 lines is to accept the pawn, gambit the rook on h8 and smash White in the coming attack. These lines can be tricky so you could additionally analyze them with an engine, just to see how exactly can you capitalize on your advantage the easiest. Again, nothing to worry here, Black has a winning attack.

[Title "White doesn't take the Black's pawn at e5"]
[fen "rnb1k2r/1p2qppp/p1pb1n2/3pp3/1PP5/P1N1PN2/1B1P1PPP/R2QKB1R w KQ - 0 14"]

Here, White is smart and doesn't wish to make early trouble. He will finish development first, and then will try to capitalize on his queenside space advantage. The most typical plan in similar pawn structures is minority attack. That is why Black played ...a6 at some point, to hinder this plan.

Black will maintain his advantage in center, and will refute any type of wing play White bases. Remember the golden rules:

Attack in the center refutes the wing attack;
Who controls the center, controls the wings too;

I would recommend you to study Orthodox defense of the QGD, and the Exchange variation of the QGD as positional transformations of the above position will have very similar plans like in the mentioned lines. M.Sadler-Queen's Gambit Declined ( 2000 ) is dated but excellent starting point. The book is clearly written and explains all the plans that might crop up here. You might need to learn about Isolated Queen's Pawn, and my answer to this question might be helpful as a starting point. For further reading I highly recommend A.Soltis-Pawn Structure Chess ( 1995 ) as it is simply awesome.

If you have further questions leave me a comment. Hopefully this helps.


Why not save the queen by playing Qa5-a4?

Because that was the move that the computer saw lost the least material. The BEST you can do there is just get two minor pieces for the queen. It gets worse after Qa4. Even just Nxc7 wins so much material that it is easy, but there is even better.

 [FEN ""]

 1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. Bc4 Nf6 5. d3 Bg4 6. f3 Bf5 7. Bd2 e6 8. Nge2 Nc6 9. Nd5 Qa4 10. Bb5! (10.Nxc7) {And the queen is still trapped, or the Ra8 is lost...at least.} Qh4+ (10... Qxb5 11. Nxc7+ Kd7 12. Nxb5) 11. g3 Qh5 12. Nef4 (12. Nxc7+ Kd7 13. Nf4 Qh6 14. Nxa8) 12... Qh6 13. Nxe6 {And it is just over.}


Like its cousin endgame KRBvKR, your ending of KRNvKR is usually drawn. It's not always drawn, of course, but generally speaking KRNvKR is much less dangerous and easier to defend than is KRBvKR. In Secrets of Pawnless Endings, John Nunn writes,

  If the defending king is not in a corner there are a few situations when the rook and knight can win tactically within a few moves, usually by a combination of skewer and knight fork, but in general the rook and knight only have winning chances when the defender's king is very badly placed.

The positions of KRNvKR are a part of existing tablebases, so we can be precise about how often it's a win: 35.9% of positions in which the strong side has the move are winning (see e.g. Ken Thompson's "Retrograde analysis of certain endgames" from 1986). Note that since that says that giving the strong side the move (which is advantageous most of the time) in a random position yields a win only 35.9% of the time, the overall winning percentage for the strong side in KRNvKR is considerably lower than that; I am unable to pin the figure down from any source so far.

For your particular game, Nunn's words can give some inkling as to whether your opponent made a mistake or was already doomed, but if tablebases have taught us anything it's that optimal play can be quite seemingly random, and that heuristics are of limited use for a reliable verdict. If you have a record of the initial KRNvKR position that appeared on the board in your game, though, then a quick Nalimov tablebase query will tell you whether or not your opponent sealed his fate during that ending or before it.


Why do some UCI engines restrict input moves to 23 when using the command prompt?

I suspect this is due to the length of the command; the one in your question is 254 characters long, close to 28 = 256 which might be a maximum command length for some engines.
I do not know a solution for this, but it seems possible to use the position command with a FEN string, for example as used in this question.


If we move white's bishop to a dark square in the Fisher-Taimanov (1971) bishop vs. knight endgame, can white still win?

I would say no.

Black's king is doing a very good job at protecting the queenside, with no possible threats on the kingside. Also, the e4 square could be a great source of counterplay for Black. In short, I wouldn't say that White even has an edge in that position. I'd prefer being Black if I could choose.

Finally, the statement "the bishop is better than the knight" is just meaningless. Even if such an advantage exists, other existing factors in the position will make too big of a difference to apply the general principle. By the way, knights are OFTEN better than "good bishops" at defeating "bad bishops"


According to this site you can play Four way chess with the same rules that you play in a classical game (include the notion of checkmate) with the difference that all queens will start on white squares. All pieces have the same movements than on the regular chess, the first player to start is the white pieces play continues clockwise around the board each player moving one piece per turn.

Also according to this, you can play two variants of Four way chess:

Regicide rules;
Classical Rules.

Quoting the site:

Regicide rules:

  Regicide means to kill the king, in Regicide Rules you must actually
  capture both enemy kings to win, rather than just checkmate them. When
  a players king is captured the rest of his pieces remain exactly where
  they are on the board and cannot move, except to capture another
  piece, or you may pass on any move after your king is captured. Your
  team must kill both the enemy kings to win. In Regicide Rules the king
  is a fighting piece too, so you dont have to get out of check and
  checkmate does not apply, and you dont have to announce check. You can
  even move into check. You can also castle out of check, through check,
  or into check.

and with the classical rules:

  When one player is checkmated on his turn all his pieces are removed
  from the board and his two opponents armies combine into one army for
  movement purposes, being allowed one move from either color per move
  that the defeated players partner gets. This is how we used to play
  but now we usually play Regicide Rules.


This is a funny looking position, which I assume you probably reached out of a poorly played Dutch defense, something along the lines 1.d4 f5 2.Nf3 g6 3.Ng5 Bg7 4.e4 e6 5.Bc4 Nh6 6.Qf3 b6 7.Bxe6 Ke7 8.e5 and so on... (or 1.d4 f5 2.Nf3 g6 3.Ng5 Bg7 4.e4 e6 5.Bc4 Nh6 6.Qf3 b6 7.e5 Ke7 8.Qxa8 Nc6 9.Bxe6) which are very weird looking...

With little analysis I think you convince yourself that black is completely lost here and Nxd4 doesn't come to rescue either. Simply put, white is a clear piece up, the queen isn't really trapped, black's king is a mess, and there's just not any piece coordination to create any counter-play whatsoever. As pointed out by TMM in the comments after Nxd4 white just retreats the bishop to b3 and protects everything, this is the simplest and best move. Or even Bc4 to preserve the bishop and even provoke Nxc2+ which leads to some fun tactics either mating the black king or trapping the queen, for example:

Q1bq3r/p1ppk1bp/1pn1B1pn/4PpN1/3P4/8/PPP2PPP/RNB1K2R b KQ - 0 1

1... Nxd4 2.Bc4 Nxc2+ 3.Kd1 Nxa1 4.Nxh7 Ke8 (4...Nf7 5.Bxf7 Kxf7 6.Qd5+ Ke8 7.Bg5 ) 5.Bg5


Why is Fritz 16 Grandmaster Playing Weak Endgames?

Fritz's 2.Kf5 is a mistake because 2.Kd5 is the only winning move according to the tablebase. Maybe Fritz suffered from the horizon effect (couldn't see far enough ahead) which turned the win into a draw. After that, a draw by repetition doesn't seem unreasonable.

Playing black, Fritz resigns but that's after seven moves, so the "horizon" is now closer, presumably close enough for Fritz to tell it lost (will lose the knight within a couple of moves with no way to stop the pawn).

I don't have Fritz, but from what I can tell "grandmaster" is one of its handicap levels (the strongest, but I'm guessing not as strong as running the engine at full strength). Handicapping an engine is not an exact science so maybe it does play this endgame in a way that's weaker than an actual grandmaster. See if there is any setting to play against the full strength engine. Also I think there is a way of getting Fritz to use a tablebase.


Based on ("b/") 25 entries in the section, its total prize pool will be $600. That money will be distributed as $250 for first place, $150 for second place, $100 for third place, and $100 for the top-finishing player under 1700 in the under 2000 section.

If there are more than 25 entries, the prize pool will be larger, and the prizes for each place will likely be adjusted proportionally. Likewise, the prize pool will be smaller if there are under 25 entries.


Would a chess game go on indefinitely if both players played the absolute best move each turn?

It doesn't matter whether the players play good moves or bad moves there is a maximum possible number of moves. There is a rule which guarantees this - the 75 move rule. It says that if 75 moves are played without either a pawn move or a capture then the game is drawn.

The relevant article of the FIDE Laws of chess is 9.6.2-

  9.6 If one or both of the following occur(s) then the game is drawn:

  9.6.1 the same position has appeared, as in 9.2.2 at least five times.

  9.6.2 any series of at least 75 moves have been made by each
  player without the movement of any pawn and without any capture. If
  the last move resulted in checkmate, that shall take precedence.

So, once every 75 moves a piece must be captured or a pawn moved (forward). Eventually all the pawns have queened or been captured and all the pieces captured and only the kings are left - which is a draw.


Does the chess community have a problem with manners and sportsmanship?

I would say that the chess community does very well in terms of sportsmanship as compared to other competitive endeavors. I think it's a mistake to compare the behavior witnessed in online chess with the behavior witnessed in basketball or billiards (incidentally, two of my other most favorite kinds of competition). I'm sure that anyone who has played any significant amount of online chess has been needlessly attacked at some point (I know I have), but the relative anonymity of the internet is the culprit there far more than anything specific about chess.

I have seen some bad behavior when playing over-the-board chess, but in my experience at least, it is far less frequent and far less severe than typical bad behavior on the basketball court, or in the pool hall. Purely anecdotal, I know, but I still think it's fair to say that etiquette is as alive and well in chess as it is most anywhere else, so long as the participants have to show their faces, or attach their real names and reputations to what they do.


Why do some strong players play 5... Be4 in Caro Kann, Tal Variation?

White probably intends to play e6 anyway, to launch an attack against the light squares. Whether Black takes this Pawn or allows exf7, White will want to play Nf3-e5 as part of his followup, and if f3 has been provoked, he will need to play f3-f4, losing another tempo and obstructing his dark Bishop.


ICCF rule for analyzing position with another human

Yes, it is legal.

ICCF: Says nothing about it, or assistance of any kind, and you can even use computers legally. Here are their rules.

USCF: "3. You may consult chess books and periodicals but not other players." Here are their rules.

With regards to the ICCF rules, my guess is that they just decided it was too hard to police computer used, so they just allow it. Books have always been permitted. Human assistance also.


There are two approaches:

1) For the piece in question you're considering to move, look at the vector going through it to the king. For example, if they king and the piece are separated horizontally/vertically, look at the line going through it to the king. Is there an enemy rook/queen on this line, such that your piece is currently between it and your king? Or, if the piece is on a diagonal from the king, see if there's an enemy bishop/queen on this diagonal. However, if your piece moves along this vector (and thus continues blocking your king), it's fine. For example, assume your king is on h8, your queen is on e5, and the opponent's bishop is on a1. There's an enemy piece on the a1-h8 vector (which your queen and king are on), so moving the queen off this vector/diagonal is illegal. But moving the queen along the vector (e.g., anywhere from b2 to g7) won't violate the pin.

2) The simpler approach is a general purpose illegal move checker. Make a list of all pseudo-legal moves, and then check each to see if it results in an illegal position where your king is en prise. This encompasses what you're trying to do with not moving a pinned piece out of the way, since it would result in an illegal position.


That depends on what you mean by 'analyse'. Any chess engine with a GUI will allow you to input a position and get sample lines from the engine, while letting you try out variations. Online services that allow this include http://lichess.org (you'd have to upload a game's PGN there first) or http://analysis.cpuchess.com/.

If by 'analyse' you mean study and learn from the nuances of a position, then the short answer is no - while a GUI might provide a way of easily resetting the board to certain states, it can't do the hard work for you.


Are there any sort of equations for how much of a handicap one should
  receive to make a game between two players with differing Elo ratings
  as balanced as possible?

The short answer is "No", there is no scientific equation, but it doesn't stop people from trying.

For instance, our club runs an annual handicap tournament in which it tries to produce a practical answer to this question. The rules for the tournament are here.

  Players are first put into numbered bands according to their grading
  with the highest graded players in band 1 and lower graded players in
  bands 2 and upwards. Then the handicap when two players meet is
  determined from the following table according to the difference
  between the players’ bands.

  0 – no handicap, first named player in the draw has white
  1 – colour, player in the higher band number has white
  2 – 2 moves, player in the higher band number has white and makes two moves instead of one to start the game
  3 – f pawn and move, player in the higher band number has white, remove f7 pawn
  4 – f pawn and 2 moves, remove f7 pawn, player in the higher band number has white and makes two moves instead of one to start the game
  5 – knight, remove b1 knight, player in the lower band number has white
  6 – rook, remove a1 rook, player in the lower band number has white
  7 – queen, remove d1 queen, player in the lower band number has white
  8 – queen and knight, remove b1 knight, remove d1 queen, player in the lower band number has white
  9 – queen and rook, remove a1 rook, remove d1 queen, player in the lower band number has white

Basically if the rating difference is less than 100 then the players are in the same band, a band difference of 1 equates to a 100 to 199 rating point difference, 2 band = 200 - 299 difference, 3 band = 300 - 399 difference, etc.

In recent years the winner's rating has varied between about 1500 and 2000 so it doesn't seem to favour any particular level although from experience I would say with large handicaps there is a definite skill for each player in adjusting how they play in terms of risk-taking.


How do you use Fritztrainer DVD with Fritz 15?

The Chessbase support site describes the process of viewing chess media files (or, what many call Fritz Trainer videos) as follows:

  If you have the lecture on a CD or DVD, [...] then
  you simply open a file using "File – Open – Chess Media File". The
  program will open a chess media window and you can sit back and watch
  the game.

Here is a screencap of my doing this process for the Fritz Trainer, Fit for the French by GM Viktor Bologan:

Note that very often the first video in a Fritz Trainer will be just the GM talking and giving you an overview. Then, you won't see any pieces moving (e.g., GM Garry Kasparov on the Queen's Gambit rapidly discusses lines without showing them on the board).

Finally, if you're opening the video files using these instructions and they don't show pieces moving when they're supposed to, you may have gotten your files from a disreputable source that has stripped them of their proprietary Chessbase metadata. In that case, you'll want to try to get a refund or download the Fritz Trainer from Chessbase.


Should I study players or specific games?

At 1400 on chess.com, openings aren't your main issue. Five moves of theory should be fine. Your opponent will throw in a Rb8 when you're attacking his king anyways so you won't be in theory for long. At your level, chess is 99% tactics.
However, the concepts behind said 5 moves are still important to know and understand. Like in the Caro-Kann, Nd7 stops white from playing Ne5, but playing that in the 2 knights trap will get you smother-mated so you need to be careful.
Sticking to improving... The best way to learn is to play while writing down the moves. Play longer games (15-25mins+ and stop writing at 5 mins on clock). Once you've played, try to compare what you played with theory. Then try again and again. Doing that will also help your tactics and board vision so it definitely is an 'all-around' trick for improvement.
Karpov (and most top level) games have a lot to learn from, but not for someone who is new as his concepts apply to middle and endgame. Often they are minor improvements on past positions. They're nice to look at with a stronger player though, but if you want to test yourself, evaluate 2000-2200 rated OTB games and look for improvements in those.
Lectures are also important and Youtube has a lot of lectures on openings. They explain a lot of the basics you might miss at first, but don't be hard on yourself if you forget some points during your games - unlike in person lectures, you can just rewatch it after 2-3 games of yours. One I like a lot is https://www.youtube.com/channel/UChxLXqMph7cRG_MHIIhlZ7A as he offers solid, yet offbeat ideas to counter specific lines.
So to answer the edit question. It's false, practice and playing your own games is what will make you remember ideas. Studying a player will have no effect either way, it should only serve as a complement to your own play.


When there is no concrete plan of action possible, the general plan should be to -

  Improve the position of your pieces
  Trade off bad pieces if possible
  Try to create weaknesses in your opponent's position
  Keep your king safe and see if the enemy's king position can be compromised.


Can one import FENs of positions involving checkmate into Droidfish?

Apparently the FEN is wrong. In the position it should be black to move next, so in the FEN there should be a "b" instead of "w". The correct FEN would be:

3b1q1q/1N2PRQ1/rR3KBr/B4PP1/2Pk1r1b/1P2P1N1/2P2P2/8 b - -


In tournament chess, is the Traxler Counterattack just a dubious opening or a blunder?

In Karpov-Beliavsky, Moscow, 1983, Black held a draw without ever being in serious trouble. Karpov played 5.Bxf7. I have never seen detailed analysis of the game.

If it suits your style, try it. But there is a HUGE volume of analysis on it. If you play it more than once you may face a booked-up opponent.


Question on how to access a move on a line outside the main line using python-chess

If you want to access every node, then you're basically iterating over the game tree. A straightforward recursion will get you there, something like:

def traverse(node):
    # do whatever stuff you want for the node here
    print(node.move)
    # terminating condition
    if (node.is_end()):
        return
    # recursion
    for child_node in node.variations:
        traverse(child_node)

And to use it, call traverse(game) where game is the root node of your game.


Three Pawns for a Knight - Why Doesn't Stockfish Like it?

Counting material is only one portion of evaluating a position. Stockfish considers space, piece mobility and activity, king safety, etc.

All of that produces an evaluation of the position, and for this one SF grades it (using LiChess) as about +2.2 (depth 31).

I note that before your knight sac Stockfish thinks you were already down by about 1.2, despite roughly equal material. That bishop on h6 controlling your weakened dark squares, for example, is clearly worth more than your knight.

As for your decision to sac the knight, from a practical point of view it seems a reasonable choice in a bad situation, because if you simply move your queen to e6 or e5, as SF suggests, white has a clear and natural plan of f4 followed by eventually opening up that file, and your clumsy rooks will not be nimble defenders.

SF suggests for white an immediate b6 after your queen takes on c4, and with that you will not get the pawn storm as you did in the game. White will have an open line to invade with his rooks (which one depends on your reaction to b6) and his extra piece will tell.


As I see it, at that level they have two options, if they suspect their opponent prepared a trap:

They trust their preparation, and their knowledge, go on as usual, and just make the best moves, and hope for the best. In the Sinquefield cup last year, or the year before, there was a game MVL-Carlsen, when this happened exactly, Carlsen was caught by MVL-s preparation, and after few moves, he found an intresting, very human move, that the engine weren't suggesting, and now MVL was fighting for survival. It was a scotch game I think, it ended in a draw, but worth to watch.
They decide to not take risk, and just chose a sideline, where maybe the other one has an edge, but they can outplay him. Tal writes in 'The life and games of M.T.' about a lot of situations like that, when he choose a sideline, because he was suspecting for some reason that his opponent prepared a suprise.


Franci de Castellvi - Narcis Vinyoles 18. ... Qg6??, a blunder by black?

These players are just pretty weak. 5...Bg4 should already have been punished by Bxf7, many more blunders follow.

Qg6 is a double attack against c2 and g2, that's probably motivation enough.


What would happen if I touch two different pieces with each hand at same time?

From the FIDE Laws of Chess, article §4.1:

  Each move must be made with one hand only.

So you are not allowed to make a move with both hands (this includes castling) and the arbiter can give you a penalty (§12.9) for this behaviour. IMHO, this should be a warning the first time you do it. In any case, because you touched the king and queen, you must make a move with either piece (§4.3):

  If the player having the move touches (...) one or more of his own pieces, he must move the first piece touched that can be moved.


What are some ways to get better at Antichess?

A strategy that I use when trying to get better at antichess is to open up your bishops. Once you to that, you are able to get your opponent in a pawn trap, making them continuously attack your pieces.


Why can I not make an en passant capture?

From Wikipedia (is this what you read?)

  When a pawn advances two squares from its starting position and there is an opponent's pawn on an adjacent file next to its destination square, then the opponent's pawn can capture it en passant (in passing), and move to the square the pawn passed over. However, this can only be done on the very next move, otherwise the right to do so is forfeit. For example, if the black pawn has just advanced two squares from g7 (initial starting position) to g5, then the white pawn on f5 may take it via en passant on g6 (but only on white's next move).

The opponent moved 14...f7-f5. There is no White pawn on e5 or g5.


Why doesn't castling reset the 50 moves rule?

I don't know the reason, but I can make a guess.

In standard algebraic notation, it's fairly easy to look at a scoresheet and see whether a capture has been made or a pawn moved.  Captures have an "x" in them, and pawn moves don't have a piece listed. But if loss of castling rights also triggered the 50 move rule, you'd have to look at the rest of the game (instead of just the last 50 moves) to see whether castling rights had previously been lost. This would seem to increase the burden on arbiters.

Also, it's rather unusual for this to matter. Most people are going to move their king (and/or both rooks) before they reach a point in the game where the 50 move rule would begin to apply.


In the immortal draw, why is the Queen sac 9...Qxa4+ considered the best move?

Where has it been mentioned that 9... Qxa4+ is the best move? but considering the alternatives it is the move that has made the game immortal, suppose black would have just followed up by playing positional chess only and managed to win, the game would have become just a case of positional example and hardly immortal. The rest of the game was not easy for white, number of times a playing a logical move would have lost white the game.


Is chess a game of skill or chance? To what extent?

If we remove the component of flawed, human players from the equation and consider just the game of chess itself as it is spelled out by the rules, then chess is purely a game of skill with no room for chance. That is, it is in principle possible for there to be a perfect chess player that plays optimally against every possible move sequence by an opponent, and that perfect player would never falter due to chance or luck. Such perfect players already exist at the level of chess positions with only a handful of pieces: endgame tablebases consist of all the information necessary for perfect play in those positions, and if you play from such a position against an opponent with access to those tablebases, chance can play no role in stopping them from getting their deserved result.

However, the problem of computing a tablebase for the starting position of chess, with its 32 pieces, is far, far from tractable. So while optimal play does exist for all positions in chess, nobody knows for sure what optimal play is for the vast, vast majority of positions. Looked at in that light, when two humans (or even strong chess engines) play a game against one another, something that can reasonably be viewed as chance (for one side at least) can definitely play a role, but for what I have in mind at least, the root cause of any outcome is still skill (or its temporary absence).

Here's an example of what I mean. In the recent Zurich Chess Challenge, Nakamura was playing a fine game against Carlsen, to the point where he had an overwhelming, winning advantage. At that point, it could safely be said that Carlsen "deserved" to lose.

[fen "4r1k1/1p3pPp/6q1/2pPpNP1/p1n1P3/P6Q/7R/K7 w KQkq - 0 1"]
[White "Nakamura, Hikaru"]
[Black "Carlsen, Magnus"]
[Event "Zurich Chess Challenge"]
[Result "0-1"]

1.d6? (1.Qf1!)

But Nakamura made a crucial mistake that let Carlsen off the hook, later followed by further poor play that even allowed Carlsen to win. If someone were to say, "Carlsen was lucky to win that day," I'd say there's truth to that. (Carlsen certainly deserves credit for defending in such a way that Nakamura could still go wrong, but even so, he was fortunate that Nakamura erred as he did.) But the luck from Carlsen's side originated from nothing more than a momentary lack of skill on Nakamura's part. Finding the right move was entirely within Nakamura's power, but he wasn't quite skillful enough to find it in that moment.

As in most human endeavors, there is some element of chance in the competitive results of chess games. But that luck for one side generally comes in the form of what kind of lack of skill one's opponent shows (and when).


How to proceed after declined Queen's Gambit?

There are multiple options here. I'm not sure what you mean by "an intermediate player", so the amount of specific lines you'd like to study can differ. I'll focus instead on types of pawn structures and middlegames you can reach. Let's take the reference position 1.d4 d5 2.c4 e6, even though there are different move orders available:
Black will sometimes play an eventual ...c5. This can lead to two types of pawn structures: the Semi-Tarrasch type, where you get pawns on e4 and d4 (see for instance 3.Nc3 Nf6 4.Nf3 c5 5.cxd5 Nxd5 6.e4). This often leads to a comfortable position for White due to his superiority in the center and not enough counterplay chances for Black to compensate for it. Here you have an example from top level players.. This line has some similarities with the Grünfeld Defence (see 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3), but I'd say Black has more chances in the Grünfeld. In my opinion you should try to reach this pawn structure as often as possible.
Another typical pawn structure that is often reached is one with an isolated "d" pawn. You'll probably play both with and against that isolated pawn in several occasions, you that's also something you may want to get familiar with. chess.com has an article about it that you may want to check out Note that this structure can also be reached when the Queen's Gambit is accepted.
Then there's the "minority attack" type of game. This happens when you capture on d5 and your opponent retakes with his "e" pawn but ...c6 has been played instead of ...c5. Here you can play on the queenside trying to get your semi-open "c" file fully open. I'm not really well-versed here so I'll let someone else choose an illustrative example by editting this answer.
Finally, there are some lines where Black will enter some variation of the Slav Defence (with ...c6). I don't know how well you know the lines after 1.d4 d5 2.c4 c6 and your preferred move choice can chance according to that. For instance, you can try 3.Nf3 Nf6 4.e3 so now you can answer to 4...c6 with 5.Nbd2!? if that's the particular line you enjoy against the Slav (here your plan would be to make a quick e4 push). But if you're not interested in playing that then you may prefer 3.Nc3. There are several lines you can choose from and plenty of transpositions between them.


How do you read this opening table presented in Modern Openings?

The columns represent the main variants which continues the movements at the head of the table. White's moves are followed by Black's in the same column. The numbers to the left of the table are the movement numbers.
The ellipsis are there to group the variants. For example, after 3 Nf3 g5 you can play 4 h4 or 4 Bc4. If White chooses the continuation 4 Bc4 he will find that Black's most sensitive responses are 4 ... Bg7 or 4 ... g4.
The lower case letters in parentheses are notes, which follow the table, which show alternative lines considered less important or that show possible pitfalls. The mark in the last move of each column refers to the model game. The evaluation of the final position is expressed with words instead of symbols such as = (equal) or + / = (the target is slightly better).


What are examples of very aggressive openings?

The most (overly-)aggressive openings I know of that aren't too bad would probably be the Danish Gambit (Accepted) and the Fried Liver Attack.

Danish Gambit Accepted:
[FEN ""]
1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Bc4 cxb2 5.Bxb2

White gets three open files and both bishops on open diagonals facing black's king; black gets two pawns.  Usually considered slightly better for black, but played occasionally even up to master level.

Fried Liver Attack:
[FEN ""]
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nxd5 6. Nxf7!? Kxf7 7. Qf3+ Ke6 8. Nc3

White sacrifices a knight to get Black's king out right away.  Proper defense is extremely difficult over the board, but played correctly, black is thought to have a slight advantage.  In most lines, white wins their material back.


This line looks unsound.

White's plan seems to be to threaten to win back the piece by 10...dxc4 11. Re1 (pinning the knight), teasing Black into weakening his king's position further by 11...f5 to defend e4, which then leads to a very complicated situation that White hopes to manage better.

However, Black is fine if he just lets go of the knight, since he's still a pawn up. Obviously, his kingside is very weak, but he can move out his queen with tempo (by attacking e4) and castle long.

11...Be6 12. Rxe4 Qd5 13. Re1/Re2/Qe2 etc. 0-0-0

The black king is safe and c4 is actually well protected. White doesn't have enough compensation left for that pawn.

To back this up, according to the Lichess online database, White has a win rate of 62% if Black plays 11...f5 (71 games), but only one of 27%/38% respectively if the answer is 11...Qd5 or 11...Be6 (11/8 games). 11...Bf5 also seems to work (35%, 20 games).

That's just not enough to make the variation appealing for grandmasters (who probably consider the refutation too obvious), and if none of them play a line it will hardly become very popular. It's a nice Blitz surprise weapon though, as you can see the majority of players from a database leaning towards fast games will choose 11...f5.


How rankings or ratings of the players are determined before the next tournament?

Are the only basis their past performances?

Yes

OR those who are engaged in Bettings play their roles?

None whatsoever.
According to the Olimpbase website:

Back in 1942 the USCF used its own chess rating system (Harkness) to
rank domestic players, while German Chess Federation did the same in
1948 (Ingo system). In 1959 one Arpad Elo was nominated chairman of
USCF rating committee and already in 1961 he published the very first
list of top US players in "Chess Life". Even though prof. Elo used to
publish his own, unofficial International Rating Lists it was 1970
FIDE Congress held in Siegen, Germany that adopted the Elo system for
official use. The first official list was to be published on 1st July
1971 and it was approved on consecutive FIDE congress in Vancouver,
Canada, in August 1971.

Elo's unofficial international ratings dating back to 1967 are available on the Olimpbase site as are FIDE ratings from 1971 to 2001. From 2001 the FIDE ratings lists are available on the FIDE website.


Is there any good app for learning openings?

In terms of apps, other than the good suggestions made so far, I definitely recommend most of "Chess King" apps, and specifically for openings:

Chess Opening Lab (1400-2000)
Chess Opening Blunders

These apps have a theory section, where various types of openings are discussed (closed, open, etc) and a practice section where you get to solve small problems specific to each opening (which you will be able to choose from).

On another note, from your description I gather your difficulties may not be necessarily opening related, but a tad more fundamental. So what you can always consider, specially at a beginner's level, is to learn basic principles about opening up the game, and not necessarily memorizing specific known opening lines. What this entails usually can be roughly summarized with the following points:

Deciding on your own style of play: open positions (e.g., 1.e4), closed position (such as 1.d4, more positional style) or the various other semi-open/closed ones.
Piece development: whatever strategy you have in mind, you first need units to execute it with, so prioritize piece development at the beginning, get out the minor pieces, occupy the centre, ...
King safety: the cliche is that you should always castle as early as possible, which is not a bad advice, but in general what matters is that you consider your king safety, and not naively undermine its importance.
Create useful space: Big part of development phase is to occupy parts of the board (often the centre) that are most accessible to your pieces (specially the minor pieces). For example, if you ignore occupying the centre of the board with your central pawns, you will have a lot of difficulties to establish centralized knights. This is often a very difficult aspect of the opening phase, as it is non-trivial and different for each opening. But think simple, you want to have active knights and bishops, so always ask yourself during your play: what structure do I need in order to post my knight here or there, or in order to have this or that diagonal open for my bishop.
Improve piece coordination: Your pieces (specially minor ones at the start) need to speak to each other, and opening theories in short provide optimized recipes to this end while refuting/limiting your opponent's play (but this is another discussion). Meaning, you have to think in terms of your collective pieces if you want to execute some plan or strategy. Amateur players tend to just opt for small tactical plans that they execute with 1 or 2 pieces: e.g., a queen and a bishop, a knight and a bishop (e.g., a bishop of f4 and a knight on b5, a typical attack on c7). Such small size attacks are often easy to parry once spotted, so try to involve as many pieces as you can for your attacks, this will make it harder and harder for your opponent to hold off. You may ask: but so when are the aforementioned "small" types of attacks useful: well, think about them in this way: on the one hand, these are small maneuvers that allow you to potentially perturb your opponent's desired setup and on the other hand, they can be seen as forceful means of rerouting your pieces to better posts. Forceful here suggests that the rerouting is without loss of tempo.
On the more practical side of things, and more related to the first point on style, you have to give different structures sufficient trials until you fully understand an opening to its nitty gritty details, details that may only at a higher level become relevant, but the good thing is the better you understand a line, the easier it will be for you to adapt if your opponent tries to refute something or deviate abruptly.
So pick up a theme of a opening you like, and play it as much as you can until you master it, then try something else, and the same routine again. This way, very soon you will have a rough idea of what to play vs many different openings, e.g. you will have a basic system vs e4, d4, and ... Again there's no recipe for what I referred to as "your basic system", because what it really means is that you will know in what terms to assess different openings and on your own out of the principles you pick up along the way, you will naturally come up with good responses.
Let me give two basic examples: Catalan (c4, d4, g3) players really like their bishops, hence the double fianchetto that often results from this line (idea being to preserve the bishops and reduce opponent choices of exchanging them), but to actually know how to leverage the two bishops takes a lot of experience and positional understanding in order to know e.g., how and when to break the centre, do I play Rc1 before c4, do I take back with knight or pawn on d4 if they take ..., and a great deal of tact, as otherwise a good opponent will easily find ways to force trade of bishops. Another opening like the Dutch: primary emphasis of the Dutch is to control the light squares on d5, e4 and the latter without having to play d5, so you preserve the possibility of playing d6 if you so desire, or if the position demands for it. With this in mind, white wants to counter these very reasons, and regain better grip over central d5,e4 squares, so first thing white annoyingly and smartly does is to give up the dark square bishop for the strong knight on f6 (which is a good re-enforcer of d5,e4 squares), e.g., 1.d4 f5 2.c4 Nf6 3.Nc3 e6 4.Bg5 Be7 5.Bxf6...
Pawn structure: its importance cannot be emphasized enough: pawn moves are the most committal moves in chess, mainly because pawns move irreversibly. This means that you need to make sure to what pawn structure you want to commit and not naively reduce your choices of expansion or defense. That's why the English opening is so powerful: it's one way of being conservative about your pawn structure, in order to have more options in reaction to what your opponent goes for. Other example, in sharp Sicilian positions, an experienced player on the black side knows not to impulsively move either the h,g and f pawns impulsively to fend off white's push, instead you have to wait until you really have to play h6,h5, g6 and so on (these are very tempting defensive moves when white is coming at you with all they have, which is the case in sharp Sicilian lines). The sooner you commit, say to g6, the earlier you've created an unamenable target weakness for your opponent to aim for. To showcase, here's a beautiful game by Kasparov (black) vs Adams:

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

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

Notice Kasparov's king-side pawns until the end ;)

Anyways, the list goes on of course and by no means should you take the above points as complete, but hopefully they do give you some pointers and I have to stop at some point :)
But what is important for you to take away, is the ways you can think about the opening phase without ever having to sit down and memorise lines, instead, from now on whenever you see a new opening being played, try to look at it with the above points in mind.


Chess engines' .dll files usable in C# projects

Take a look at the C# port of Stockfish by bpfliegel. To my knowledge it is complete (was able to compile and run it) and even though it has not been updated in 11 months at the time of this post it is certainly much stronger than the other engines listed. When I tested its perft function it on my machine it was only a factor of 1.5 slower than the original C++ implementation.


Why does black gain from this "center fork trick"?

White is enjoying a space advantage in the center, but not anymore after ...Nxe4. It would be the "equivalent" of playing a ...d5 push, which unfortunately doesn't work in this position.
White can reply to 1...Nxe4 with either 2.Nxe4 d5 3.Bd3 dxe4 Bxe4, which would leave Black with an at least equal position, or with 2.Bxf7+ Rxf7 3.Nxe4 which would allow Black to start putting pressure on the center (let's think of moves like ...Nc6 and ...e5 for instance)


In the books Wojo's Weapons, why was Wojo occasionally known to say "I'm too lazy!" when asked why he didn't play 1. d4 instead of 1. Nf3?

If I am not wrong, if you want to play c4, d4, Nf3, g3, (not against everything, but against most defenses), then the difference between starting with 1. Nf3 and starting with 1. d4, is that starting with 1. Nf3 avoids all of these openings:

That is exactly the reason why I always open with 1.Nf3 :)

You should have seen the look on some faces after they realize they can't play their gambit openings and must agree to play "dull" game. I really don't care, since I will always be rock-solid and safe, and since I am White I can usually open the center if I want "trouble".

  At the price of allowing Black to play the English.

Yeah... But it's not so bad, since English is so rich in ideas that it rarely ends in a draw if at least one side fights really hard for a win. This can be useful against lower rated opponents because they can't spring some dull opening line and draw by "suffering" all game. Theory is less important, than knowledge of plans which is also great, since lower rated opponent can't draw because he just bashed out 20+ moves of forced line.

As for equally rated opponents, this is great opening as it allows you to overpower the opponent with your intelligence and creativity, which should suit your style, based on your earlier posts.

  Technically starting with 1. d4 also allows White to play these three variations:
  But since White is going to also play Nf3 anyway (on move 3), he is not going to play any of those variations.

Which is the reason you will not see 1.Nf3 at the top so often -> the flaw of this move is that it avoids the best lines for White in many openings. Black can reach full equality rather easy ( like in QGD Exchange line... ), but still, positions are enough unbalanced for you to win. With 1.Nf3 you sacrifice objectively the most dangerous lines for Black, for safety and flexibility. It all depends of person's style. I like solidity, and have no problem with playing equal positions. Just because the position is equal desn't mean it is a dead draw. If you are creative, you can sharpen it and play for a win...

  So if we intend to play c4, Nf3, d4, g3, I would believe that choosing to start with 1. Nf3 is the most intelligent choice since it avoids so much openings at the (small) price of allowing Black to play the English.

Indeed. Just remember that this move order offers you no advantage. You will always play equal positions, but you will be rock-solid and flexible. Consider the option of playing King's Indian Attack, instead of playing d4 for example... This is a good option for White too, you do not need to limit yourself with d4+c4 pawn formation.

  So what did I miss? Does starting with 1. d4 avoids other openings that 1. Nf3 allows? Are there other advantages of starting with 1. d4 ?

1.Nf3 cuts down on the amount of theory you need to learn, but you will never play the most critical lines for Black. With 1.d4 this is not the case, but you will have to learn much more, since you can't bypass some heavily theoretical openings... It's up to you to make the choice.


Is it unsportsmanlike to underpromote to improve my chances?

If, as you say, you are "improving your chances", then it's not unsportsmanlike.  Even if your opponent misunderstands, he doesn't really have much to complain about - if he doesn't want to play on he is free to resign.

  I barely care about my opponent not resigning when he should.

Good, because demanding that your opponent resign IS unsportsmanlike.


Prashant what you describe is called blindfold chess and I've edited your question accordingly.
Humans have been playing blindfold chess for more than a thousand years and there are even blindfold tournaments. From Wikipedia:

Today there are Blindfold Chess Tournaments held throughout the year,
with the highest profile event previously being the Melody Amber
Tournament, held in Monte Carlo until 2011. Of the modern day players,
Vladimir Kramnik, Viswanathan Anand, Alexei Shirov and Alexander
Morozevich have proven themselves to be particularly strong at
blindfold chess, being alternating winners of the Amber Tournaments
between 1996 and 2007. Levon Aronian won Amber 3 times since then and
won the blindfold event at the 2012 SportAccord World Mind Games.

Not only are blindfold games and tournaments commonplace but there is competition to see who can play the most blindfold games at the same time.
In the 20th century the record was held by George Koltanowski who played 34 simultaneous blindfold games on 20 September 1937, in Edinburgh.
The current world record is 48 blindfold games played simultaneously by Timur Gareyev. This was sufficiently big news to make the regular press and was reported in Leonard Barden's chess column ion the Guardian newspaper.

Do you feel chess masters who can play Blind chess games by winning
shows more mastery over chess game than who can look at chess boards
and win?

Neither Koltanowski nor Gareyev are anywhere near world champion level although Koltanowski was a GM and Gareyev is currently a GM. Giving a blindfold simultaneous display is a party trick. It is impressive and difficult but nowhere near as difficult as beating the world champion.


Stockfish 10+ (depth 20) disagrees with the other answer, because it thinks that White's opening here is sound and evaluates the final position as +1.4. I would be very interested to see anyone play as Black starting from that position and beat Stockfish 10+. If nobody can, how can one consider White to have played badly?


What serious use of en passant has been made recently?

I'll give an example that isn't from a world championship match, and isn't recent either. In fact, it doesn't even have an en passant capture in it. (Bear with me.) It does have a world champion playing in it, though, and more importantly, I hope it illustrates the following: even when no en passant capture actually occurs in a game, the fact that it is possible might be playing a very big role. This is not entirely unrelated to the old chess saying, "the threat is stronger than the execution."

In the game Alekhine - Yates (London 1922), we have the following position after black's thirty-first move:

[FEN "r3r1k1/2R3p1/2R1p2p/3pNp1P/p2P1K2/Pp2PP2/1P4P1/5b2 w - - 0 31"]

1. g3 1... Ba6 (1... g5+ 2. hxg6) 2. Rf7 Kh7 3. Rcc7 Rg8 4. Nd7 Kh8 5. Nf6 Rgf8 6. Rxg7! Rxf6 7. Ke5 7... 1-0 (7... Rff8 8. Rh7+ Kg8 9. Rcg7#) (7... Raf8 8. Rh7+ Kg8 9. Rcg7#)

Alekhine has boldly played his king forward with the idea of infiltrating the black position via e5. On the previous move, Yates had attacked his g-pawn with 31. ... Bf1 and Alekhine replies simply with 32. g3 to keep the pawn safe, ready to get back to business after that. Looking at the position, we can see that if Alekhine didn't have the en passant capture at his disposal, then Yates would be able to checkmate him with 32. ... g5. But since the rule is in effect, Alekhine's king is actually perfectly safe, and in a strong position to help his other forces attack.

Now Alekhine didn't have to play 32. g3 setting up this "pseudo-mate" possibility. But still the point is that the white pawn on h5 and its en passant threat plays a big part in Alekhine's suffocating clamp on the black position, and his successful invasion. Yates resigned only a few moves later, with Alekhine's king delivering the final blow on e5: 32. ... Ba6 33. Rf7 Kh7 34. Rcc7 Rg8 35. Nd7 Kh8 36. Nf6 Rgf8 37. Rxg7! Rxf6 38. Ke5 1-0.

Yates must lose his rook, because if either rook moves to f8, Alekhine has mate in two with 39. Rh7+ Kg8 40. Rcg7#. To reiterate the larger point:

  Many potential en passant captures that never actually occur, because the mere possibility of it discourages the other player from ever making the two-square advance in the first place, still play a major role in the game. This aspect - the most effective en passant is perhaps the one you never see - is one reason why, superficially, the en passant capture might seem like a less important/significant feature of chess than it actually is.


Would it be sufficient here to write Ne4+ (meaning Nce4) only (i.e.
  without the "c" but with "+"), as Nfe4 would not be check?

It depends on exactly what you mean by "sufficient". By "normal" definitions of "sufficient" the answer is obviously "yes". "Ne4+" disambiguates and leaves the human reader in no doubt which knight was moved.

However it doesn't work in FEN diagrams. You need to specify Nce4 to get it to work. So, then the answer would be "No".

The FIDE Laws of Chess describe how you should annotate your games in Appendix C and that does not allow for using check as a way of disambiguating between two different pieces of the same type moving to the same square. However there is no penalty specified for mistakes. It is up to the arbiter to decide and that will only happen if it is noticed.

In real life the most that might happen is that if the games are transcribed for sending to FIDE or for publishing the player might get a scolding from the arbiter tasked with this chore, but this is extremely unlikely in this case and would happen long after the game is completed.

Mistakes far worse than this happen all the time and the only comeback from the arbiters is when the scoresheet is completely illegible or grossly incomplete. Vigilant arbiters will notice these misdemeanors during the game and warn the player concerned to mend their ways.


Depending on what you are looking for, there are a few interesting books. If you are looking for a book to start to learn the opening, I suggest you take a look at:

Starting out: Modern Benoni by Endre Dr. Vegh.

In such case, you may also want to round up your repertoire with the companion book:

Starting out: Benoni Systems by Alex Raetsky.

Which provides a more complete coverage of some similar lines (but not exactly the same, although some intersection is inevitable) that are not exactly achieved through the main move order.

If you already know how to play or what you want to play and are looking only for ideas, then the Dangerous Weapons book is definitely what you may want to check:

Dangerous Weapons: The Benoni and Benko by several authors.

Last but not least, if you are already a well versed player on the Modern Benoni and just want to keep up with some theoretical developments in the last years, and what trends are being followed, I strongly suggest the book:

Chess Developments: The Modern Benoni by Richard Pallister.

My experience with the Chess Development series arises from the Dragon and Grunfeld books, which definitely are worth the money if that is what you are looking for.

I obviously have not fully read them all. I have read a couple of chapters of the first three books, and the last one comes from my experience with the series as a whole.


Why did black choose 1... Kxg7 instead of 1... Rfe8 in this puzzle?

I've done this puzzle today too! It's Chess.com's puzzle of the day =)

I have analysed it with Houdini 3 Pro. Here is what it says after 1.Bxg7 :

1...Kxg7 : +5.07
1...Rf7 : +5.43
1...Rfe8 : +5.52

After 1... Rfe8 your move 2. Bxc6?? is a blunder and lose a lot of White's advantage (White is still probably winning but not by much). Houdini evaluates it as only +1.96

The killer move is 2. b4!! which Houdini evaluates as +5.52

It will continue: 2... Nxb4 3. Bxf6 Rac8 4. Qxe5 Bc4 5. Be7

(It's pretty much forced, all other Black replies are much weaker. 3... a6 is answered by 4. Qc7 ; while 2... Qd8 is answered by 3. Rfd1)

Then here are three lines:

5... Bf7 6. Bxb4 Qxb4 7. Rab1 Qxb1 8. Qxe8+ Rxe8 9. Rxb1 Rxe2
5... Qd8 6. Bxd8 Rxe5 7. Nd6 Rxd8 8. Nxc4
Rxe2
5... Qxb5 6. Qxb5 Bxb5 7. Bxb4 Bxe2

According to the omniscient Houdini the move 1...Rfe8 is technically slightly inferior to 1... Kxg7. But I think you are right: if it was a practical game, Black should play 1... Rfe8 because it gives White a harder time at finding the correct optimal continuation.

Trading Queens with 1... Kxg7 simplifies the position and makes it very easy to win for White. But after 1... Rfe8 the position is still complex and White may make a mistake. I believe Black's best hope is to play 5... Bf7 6. Bxb4 Qxb4 7. Rab1 Qd2?! which keeps the Queens on the board.


Personally, I love a number of great books, and there is still no substitute. You can then plug positions into a computer to test yourself.

I still love Fine's "Basic Chess Endings". Despite the errors, many corrected later in the Pal Benko edition, it gives a great sense of WHAT you are trying to accomplish in any type endgame. Simply by reading over all the examples, and the sub-examples, you will absorb a lot. Each sub-example, while meant to show an exception, or other deviation, is also reinforcement of the main idea.

For example as to my comment about "WHAT" you are trying to accomplish, take a minor piece endgame where you are up a pawn. The basic plan is to create a passer, and if your opponent blocks with the K, you run with your king to attack and take his other pawns. It he just tries to block it with the piece, you run over and force him to give up the piece for the pawn.

I studied this book when I was rated just 1036, and much of what I learned has stuck with me through being a Master almost 40 years later. No less than World Champion, Mikhail Botvinnik, considered it the best book on the endgame (although many greats ones have come along since). Fine's words are chess gold.

Next, I really like "100 Endgames You Must Know: Vital Lessons for Every Chess Player" by GM Jesus de la Villa. Not many books get a fourth edition, which is a testament to this book's appeal. In addition, he recently added "The 100 Endgames You Must Know Workbook: Practical Endgame Exercises for Every Chess Player", which lets you apply the 100 endgames from the first book in practical game exercises.

Lastly, if you really get strong, I still consider "Dvoretsky's Endgame Manual" THE single most instructive book ever written. That said, it is not for novices, and expects a lot of prior endgame knowledge. Similar to de la Villa's recent workbook, Dvoretsky also wrote "Tragicomedy in the Endgame: Instructive Mistakes of the Masters", which shows practical games involving information from DEM.

No matter what you do though, endgame study requires time and effort; however, unlike opening study, this study will stick with you for a lifetime.


20 years old is not that late to start.  Any amount of time spent can help improve or maintain skills.  Consider how much time you would like to spend and commit to it.  Adjust to ensure you are enjoying your chess time.  Easy to improve when having fun. An hour a day is fine to start.
How you spend you time is also important.  There is much good advice on this site, for example this
You will not get a title playing on chess.com.  Consider playing in tournaments that lead to titles.  Probably your rating will be different then chess.com so that will give you a better idea how close you are to your goal.
I learned to play when I was 7, but in my teens I did not have anyone better than me to play so I could not improve.  Once I started university it was easy to find folks better than me and I started playing and studying chess much more.  Most of my chess improvement was during university.


How was the FIDE rating system introduced?

In Robert Howard's article "A complete database of international chess players and chess performance ratings for varied longitudinal studies" (Behavior Research Methods 2006, 38 (4), pp. 698-703) he writes:

  The first FIDE rating list is dated December 1970 and was based on
  games in international tournaments in approximately the previous 2
  years.

I guess that Arpad Elo will describe this procedure in more detail in his book "The Rating of Chessplayers, Past and Present" that, unfortunately, I do not own.


Why did Lilienthal resign after (37. Rc1) in Lilienthal vs Botvinnik (USSR Championship, 1945)?

White resigned simply because the c3 knight is poison due to a mate in 3 starting with Re1.

Therefore black can just play hxg4 hxg4 then undermine the e5 knight with g5. Notice that the e5 knight gets trapped. There is no way out of both these mating conundrums and these knight trap schenanigans (schevenigen lol!)

Here is the diagram if we give White a free move. That's right, Black had the move in this game and he will smash with hxg4 followed by trapping the knight on e5 (after g5), but even if White moves first, Black is still smashing!!!

[FEN "8/ppk3p1/1r6/3pN2p/2p2PP1/2n1r2P/P2R4/K1R5 w - - 0 0"]

1.Rxc3 (1.Rdc2 (1.gxh5 Re2 2.Rxe2 Nxe2 3.Rc2 Nxf4 4.h4 Kd6) 1...Ne2 2.Rf1 (2.Re1? Nd4) h4
3.g5 Re4) 1...Re1+ 2.Rd1 Rxd1+ 3.Rc1 Rxc1#

By the way, I checked this position with a computer (Stockfish 8, depth 28) just to make sure I was right, and the initial position here before Rxc3 scores as -5.4 (if Black moves as in the game) and -3.2 if White moves here. Now here is the position if it is Black to move, as in the game.

[FEN "8/ppk3p1/1r6/3pN2p/2p2PP1/2n1r2P/P2R4/K1R5 b - - 0 0"]

1...hxg4 2.Nxg4 (2.hxg4 g5 3.Nf7 (3.Nxc4 dxc4 4.Rdc2 gxf4 5.Rxc3 Rxc3 6.Rxc3 Kd6
7.Rxc4 Ke5 8.Ra4 f3) 3...gxf4 4.Ng5 Rg6) 2...Re2 3.Rxe2 Nxe2 4.Re1 Nxf4 5.Rh1
(5.Rf1 Nxh3) 5...c3 6.a3 d4

If White doesn't play right, then Black just immediately wins material or mates. If White plays right, then Black gets a winning rook endgame because of his massive advantage in pawns.

At the end of the day, he probably resigned 20 or so minutes after making that move just based off the endgame. Remember, Mikhail Botvinnik was like the most heavy duty Russian chess dude out there.

Chess was serious business to him and the Russians trained in endgames more than other people did. Botvinnik actually tackled a line of the Semi-Slav (a line of the Semi-Slav Botvinnik I think??) for 100 hours worth of preparation! These top players gave Chess their 110%.


A plan without (extensive) analysis can only be given in very stable structures. Here, the position is pretty tactical and volatile. White might be able to round up the e3-pawn with Nd1 and h3. Then black has to calculate hard to not wind up in a very bad endgame.

So here my "plan" during a game would look like this: Use any tactical trick you can find to not lose the e3-pawn, and if you cannot avoid losing it, grab as much material for it as you can.

Concretely, after 1.Nd1 Bf4 looks like a decent move. Then one "tricky" line would be: 1.Nd1 Bf4 2.g3 {2.h3 Bg3} Bb8 3.Kg2 {3.Nxe3 Ba7} Ba7 4.h3 Nf2 5.Nxe3 Nd3 6.Rd2 Nc1 hitting both rooks.

All this depends on white playing the most obvious move, Nd1, but she might try to strengthen her position in any other way and then you have to come up with different tricks. What you might want to keep in mind is:

The bishop is happier on the a7-g1 diagonal.
The rook might want to invade the second rank or hit the a4-pawn.
The knight wants to jump around and fork things up.
All considered: Active play is necessary.


CLI tool to let chess engines play each other


Analysis on Alekhine-Lasker 1934, after 18.Qd6

After 20...Ng8 21. Nc6! Re5 22. Ne5 and wins f7 too due to the dual threats of Nd7 and Nf7, both winning the exchange. So, 22...Nf6 is forced, and white is just winning there.

It is going to be Q vs. R, B, and two pawns; but the problem is that white will control both files, and the black K is still not safe.

[fen "r4rk1/pp3ppp/1qpQ1n2/4nN2/8/1B2P3/PP3PPP/2R2RK1 b - - 0 1"]

1... Rae8 2. Ne7+ (2. Rc5 Nfd7) Kh8 3. Qxe5 Ng8 4. Nxc6! Rxe5 5. Nxe5 Nf6 {forced} 6. Nf7 Kg8 7. Rfd1 {is crushing since you cannot take on f7 due to mate with Rc8}


If you fail to move the king out of check (for any reason) what is the status of the game?

FIDE Laws of Chess, 7.4.1:

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

So, based on your/your opponent's written recording of the moves, the position will be restored to the last position before the illegal move. Articles 4.3 and 4.7 refer to touch move - in replacing the illegal move, you must move the same piece that made the illegal move, unless that piece has no legal moves.

In addition:

  For the first completed illegal move by a player, the arbiter shall give two minutes extra time to his opponent; for the second completed illegal move by the same player the arbiter shall declare the game lost by this player.


According to the website for This Week In Chess, the release date for Fritz 15 is November 27, 2015. Also note that now they only sell one version of the product. There no longer is a separate Deep version.


I know I can play longer games; I just want to know how I can improve my time 'problem' so I can also play shorter games

My advice is not going to address how you can speed up your thinking or improve your clock handling skills. My advice is to play longer games.

I personally cannot think quick enough for bullet or blitz chess. My 'home' is rapid play or slower. The slower time controls also suit my more positional style and a preference for the endgame.

When it comes to time controls, choose the time controls that suit you and your style, otherwise you are going to go against your grain and become frustrated.


How is White winning in this OTB position?

In the picture, it could be either the two simply agreeing to the draw, or black resigning, depending on who has the move. Both are typically followed by a handshake.

White to move is a draw.

 [FEN "8/3k4/5p2/3K1P1p/7P/8/8/8 w - - 0 1"]

 1. Kc5 {The only move} Kc7 {Again the only move.} 2. Kd5 Kd7= {Both sides are forced to repeat here, and it is a draw.}

Now, black to move loses as black has to cede space, and then material.

 [FEN "8/3k4/5p2/3K1P1p/7P/8/8/8 b - - 0 1"]

 1... Ke7 2. Kc6 Ke8 3. Kd6 Kf7 4. Kd7 Kf8 5. Ke6 Kg7 6. Ke7 Kg8 7. Kxf6 Kf8 8. Kg5 Kf7 9. Kxh5 Kf6 10. Kg4 $18


Looking for a single, good opening that revolves around a “crab” pawn structure

To answer your question, there are no good openings that revolve around this "crab" pawn structure. This is because this structure takes a lot of pawn moves, decreases the mobility of your bishops, and creates weakness on the kingside. It would even be difficult to come up with a respectable variation of any opening that has this pawn structure (perhaps the variation in the link provided is playable, but I don't think it gives an objective advantage).
Of course the pawn structure in the link is different than the one you displayed. Either way, I recommend avoiding these "crab" structures at all costs.
If you want to surprise you're opponent with unorthodox openings in an aggressive manner, try some gambits out. For example, King's Gambit, Smith Morra Gambit, Evans Gambit, etc.


How to force engine (eg. Stockfish) to play position till checkmate in Lucas Chess?

It's possible, but you'll may need to update the source code.

In https://github.com/lukasmonk/lucaschess/blob/843be9f57baa3f631c05181b1012df844f53c84b/Code/QT/PantallaEntMaq.py

    # Resign
    lbResign = Controles.LB2P(self, _("Resign/draw by engine"))
    liResign = ((_("Very early"), -100),
                (_("Early"), -300),
                (_("Average"), -500),
                (_("Late"), -800),
                (_("Very late"), -1000),
                (_("Never"), -9999999))
    self.cbResign = Controles.CB(self, liResign, -800)

The GUI will resign if the score goes below 800 cp. You can do this:

self.cbResign = Controles.CB(self, liResign, -9999999)

This will disable auto resign for the software.


What is the origin/history of the traditional piece values?

In Claude Shannon's paper of 1949, he quotes those values as part of his evaluation function:

  Most of the maxims and principles of correct play are really assertions about evaluating positions, for example: -

  (1) The relative values of queen, rook, bishop, knight and pawn are about 9, 5, 3, 3, 1, respectively. Thus other things being equal (!) if we add the numbers of pieces for the two sides with these coefficients, the side with the largest total has the better position.

  (2) Rooks should be placed on open files. This is part of a more general principle that the side with the greater mobility, other things equal, has the better game.

  (3) Backward, isolated and doubled pawns are weak.

  (4) An exposed king is a weakness (until the end game).

  These and similar principles are only generalizations from empirical evidence of numerous games, and only have a kind of statistical validity. Probably any chess principle can be contradicted by particular counter examples. However, form these principles one can construct a crude evaluation function. The following is an example: -

  f(P) = 200(K-K') + 9(Q-Q') + 5(R-R') + 3(B-B'+N-N') + (P-P')
      - 0.5(D-D'+S-S'+I-I') + 0.1(M-M') + ...

He doesn't cite an explicit reference for these values, but appears to treat them as well-known.  He does cite three obviously chess-related books published from 1937 onwards.

However, Nimzowitsch's My System was first published in 1925, and it is not immediately obvious that specific relative values are assigned to pieces; a text search for "piece value" yields only oblique references to the idea that a rook is so much more valuable than a pawn that the former should not be tied down to defend the latter.  With that said, My System is a textbook about positional play, so could be said to have moved beyond simple material analysis.

Also first published in 1925 was Lasker's Manual of Chess, which starts from the very basics - the form of the board and the rules of moving pieces.  Here, we do find a numerical description of piece value, near the end of the "first book":

  We rivet our attention on the games of the experienced […] and among them certain regularities show very plainly.  […]  Hence, we know that ceteris paribus (all else being equal) knight and bishop are even, either is ceteris paribus worth three pawns, rook ceteris paribus as strong as knight or bishop and two pawns, queen very nearly as strong as two rooks or three minor pieces.

From this prose, we can extract B=N=3, R=5, Q is a little less than 10 (2xR) or 9 (3xB/N).

He then goes on to point out some situations where the qualification ceteris paribus is most definitely not true.  But again, it is not immediately clear from the text whether Lasker was the first to explicitly write these values down, or whether he himself learned them from elsewhere.

A subsequent answer notes that Staunton published a similar set of values in 1847, but essentially quotes Q=10 instead of Shannon's value of 9; these values in turn appear to have been established even earlier.  So we can see that Lasker may have obtained these piece values from Staunton (a very influential figure in chess, so Lasker would certainly have read him) and, before writing his own chess manual three-quarters of a century later, revised them based on his own experience.

It appears that Lasker revised his own values yet again for a later 1947 work, to values somewhat different from Shannon's: B=N=3.5, R=5, Q=8.5.

It is also worth noting that modern chess engines sometimes choose a different set of values entirely, especially when they are self-optimised.  Stockfish uses N=4.16, B=4.41, R=6.625, Q=12.92, which roughly corresponds to devaluing an individual pawn more than anything else.  Nevertheless, the "standard" values appear to have remained reasonably stable through the late 19th century and most of the 20th.