# Question
Title: What is "spaced repetition" and how can I use it to improve my chess?
What is spaced repetition?

How can I apply it to studying and improving my chess?

Is it just for tactics or can I also use it for openings and endgames?

What experience do people have with it and with what results?

# Answer
Gwern Branwen's page on spaced repetition has more than you ever wanted to know about the subject.

I have used it to memorize opening lines, tactical and strategic problems, and theoretical endgame positions. My personal experience was that after over a decade at 1800 USCF I quickly improved to 2000 USCF (and have stayed there). I do not know how much of this was due to spaced repetition or whether it would work as well for anyone else. I have written about my experience.
> 2 votes

# Answer
Spaced repetition is a learning technique that repeats content after increasing time spans according to learning success, i.e. faster for stuff you haven't grasped yet, longer if you do well.

In chess this is either used to learn a certain set of (easy) tactical exercises basically by heart ("woodpecker method" according to Axel Smith, Michael de la Maza, …), which is supposed to improve your tactical pattern recognition.

Or it is used to learn your opening repertoire by heart. For example by using the software Chess Position Trainer.

In my experience both are probably beneficial, but I cannot offer more than anecdotal evidence. Also you should complement it with exercises that tax more than your memory.
> 4 votes

# Answer
The tactics training websote http://ChessTempo.com uses the spaced repetition algorithm developed by the company SuperMemo to organize a review routine for tactical problems. I wrote an introduction to this kind of tactics training at http://www.apronus.com/chess/trainingtactics.htm
> 1 votes

---
Tags: training
---


title: How to host an own chess ICS server?

text:
# Question
Title: How to host an own chess ICS server?
I want to host my own chess server (just in my home network, nothing public) to play chess with some friends.

I did some research on it and found out that the protocol used to realize a chess server is called - like the server - ICS. The results I've found were very vague, most of them point to the existing big hosters like freechess.org, chess.com etc.

Are there any tools to host an own chess server?

# Answer
You can setup lichess locally with this guide: github.com/ornicar/lila/wiki/Lichess-Development-Onboarding. The creator of lichess said this should work over irc.
> 2 votes

---
Tags: engines
---


# Question
Title: Building a chess using magic bitboard... how do I know if the movement is valid
OK I have read a lot of things on the web most of them using Java that doesn't have unsigned int. I am working on Objective-C that has unsigned int.

Lets consider the following scenario.

The board is like this:

`A1` is on the lower left and is the least significant bit and `H8` is on the top right and is the most significant bit.

I have constructed the bitmasks for the movements of all pieces for all positions on the board.

Suppose the following simple situation:

1. the game will start. All pieces are on their initial positions.
2. the user tries to move the knight on `G1` to `E2`.

Obviously this movement is impossible because there is a pawn on `E2`.

How do I discover if a movement is valid?

Ok I have the bitmask of all pieces that is this:

`1111111111111111000000000000000000000000000000001111111111111111`

and I have the bitmask of the possible movements for the knight at `G1` that is

```
00000000
00000000
00000000
00000000
00000000
00000X0X
0000X000
00000000

```

or in bits

`0000000000001000000001010000000000000000000000000000000000000000`

if I `AND` these two

`1111111111111111000000000000000000000000000000001111111111111111` `0000000000001000000001010000000000000000000000000000000000000000`

I get

`0000000000001000000000000000000000000000000000000000000000000000`

all I know is that there is a piece at that point but I am not seeing how this tells me if that is a valid move or not.

Another question is this: suppose this move would let my king under attack. Obviously the move would be technically possible under the knight rules of movement but impossible because I cannot do a move that puts my king under attack.

How do I get these informations? Thanks

# Answer
> 2 votes
Let me answer your questions for @MikeJones:

1. You will need to store the generated moves in a bitboard. The following code example should work:

```
unsigned int moves = .... // This gives a bitboard of where your knight can move
unsigned int whitePieces = .... // This gives a bitboard of where your white pieces are

if (moves & whitePieces) {
    // If your code reaches here, one of your moves is invalid because we can't capture our own piece
} else {
    // If your code reaches here, your moves are pseudo-legal
}

```

Note that I say `pseudo-legal`, because it's only legal if the move itself doesn't expose your own king. You'll need some logic to check it and this brings us to the second point.

2. Mike's solution for checking king attacks will work but it's slow. You should do what Stockfish is doing (I don't see a better and faster way). In position.cpp, Stockfish does this:

* If the moving piece is the king, then the move is only legal if the destination is not under attacked by the opponent.

    ```
    if (type_of(piece_on(from)) == KING)
        return type_of(m) == CASTLING || !(attackers_to(to_sq(m)) & pieces(~us));

    ```

    This can be easily implemented by AND, because you will always need to keep a bitboard for white pieces and black pieces.
    * If the moving piece is not the king, the move is only legal if it's not pinned or it's moving along the ray towards or away from the king:

    ```
    return !(pinned & from)
        ||  aligned(from, to_sq(m), square(us));

    ```

    You can construct a pinned bitboard by going through all the pieces, and ask which of them is blocking the enemy attack to the king. Something like this will work:

    ```
    unsigned int enemyAttacks = ... // Bitboard of where the enemy pieces can attack the king
    unsigned int myPieces = .... // Bitboard of where my pieces and pawns are

    if (enemyAttacks & myPieces) {
        // One of our pieces is blocking the attack
    }

    ```

# Answer
> 2 votes
Make a bitboard of all the white pieces. If the AND of the possible knight move and the white pieces is TRUE, then the move is illegal--attempting to capture your own piece.

The simplest way is to make the move and check if the King is in check.

The method I use is a little more complicated. First I check is the King is in check now. If the King is in check, I can delete all non-king moves which do not finish on the line the check is coming from. If the King is not in check, I only have to check the line if the piece moves from the line. The code seems harder to write, but the validating routine runs less lines.

To explain the latter case better. If the King on f1 is not in check, and I move the Knight on f3, I only have to examine if a check was masked by this Knight. If a Bishop moved from d3, I only have to examine if the opponent's Bishop or Queen is checking from c4, b5 or a6.

---
Tags: engines, software, attack, bitboard
---


# Question
Title: Rook and knight used together within the same move - legal?
This is my first question on chess beta and I don't know if I'm insane or if the cpu is broken. So I was playing chess against a CPU on the iPhone with the app 3D Chess Game, and the CPU (playing black) made an odd move.

Black to move:

White to move (one move later):

I obviously edited this to simplify it, but the basic idea is same. That is:

**Black moves `Rook on a8 to d8` and `Knight on g8 to f6` in the same move.**

Is this legal? Or is it just a bug in the system?

# Answer
> 2 votes
That's either a bug or some non standard chess variant

---
Tags: engines, analysis, knights, rooks, illegal-move
---


title: Basic software for any chess enthusiast

text:
# Question
Title: Basic software for any chess enthusiast
What is the beginner's starter pack you would recommend for any chess enthusiast?

I am not asking for any specific product just the general software category.

For example I think everyone should have a:

**chess engine**,

a **graphical chess board** (preferably one that supports XBoard and UCI protocol),

and a **chess database** (like SCID).

Anything, I am missing here?

# Answer
> 4 votes
**Interactive tutorials**, for example presenting a game with commentary and periodically asking you to provide input, e.g. what you think is the best move, how to exploit a mistake etc.

**Passive tutorials** where you just look at the screen. Youtube is best placed for this.

**Set up a position and play against the computer** is great for setting up endgames and taking resigned positions from master games and playing them against the engine. After all, the hardest thing to do in chess is to win a won game.

**Online arena** for playing against real opponents under various time controls.

**Mini games** such as knight's tour, pawn wars etc. to practice key skills such as visualisation and endgame technique.

# Answer
> 1 votes
I think a **tactics trainer** is definitely great to have. While there are many available online, having an offline tactics trainer is useful when I'm on the go.

# Answer
> 1 votes
In addition to the software listed, I would add the web site http://www.chessgames.com/ -- It has a setup that lends itself quite well to teaching you the things you'd learn from software:

* Game collections with a game viewer.
* Ability to comment on and read others' comments on games.
* A "guess the move" page to train on selecting the next move in some great historical chess games.

FULL DISCLOSURE - the site is "freemium" so although many features are free, you can if you choose sign up for their paid membership. I paid for it, but whether you do is up to you.

Good luck.

---
Tags: software
---


# Question
Title: How I tell the UCI engine to show less info during search?
Is there a UCI command to output only selected info? For example if my input is

```
setoption name MultiPV value 3 go depth 8

```

I get info for every depth itineration in the search:

```
info depth 1 seldepth 1 multipv 1 score cp 74 nodes 63 nps 31500 tbhits 0 time 2 pv e2e4
info depth 1 seldepth 1 multipv 2 score cp 70 nodes 63 nps 31500 tbhits 0 time 2 pv d2d4
info depth 1 seldepth 1 multipv 3 score cp 68 nodes 63 nps 31500 tbhits 0 time 2 pv e2e3
info depth 2 seldepth 2 multipv 1 score cp 79 nodes 158 nps 52666 tbhits 0 time 3 pv e2e4 b7b6
info depth 2 seldepth 2 multipv 2 score cp 73 nodes 158 nps 52666 tbhits 0 time 3 pv e2e3 b7b6
info depth 2 seldepth 2 multipv 3 score cp 63 nodes 158 nps 52666 tbhits 0 time 3 pv d2d4 b7b6
info depth 3 seldepth 3 multipv 1 score cp 94 nodes 294 nps 98000 tbhits 0 time 3 pv e2e4 d7d6 d2d4
info depth 3 seldepth 3 multipv 2 score cp 94 nodes 294 nps 98000 tbhits 0 time 3 pv d2d4 d7d6 e2e4
info depth 3 seldepth 3 multipv 3 score cp 53 nodes 294 nps 98000 tbhits 0 time 3 pv e2e3 d7d6 d2d4
info depth 4 seldepth 4 multipv 1 score cp 92 nodes 642 nps 160500 tbhits 0 time 4 pv e2e4 e7e6 d2d4 b7b6
info depth 4 seldepth 4 multipv 2 score cp 89 nodes 642 nps 160500 tbhits 0 time 4 pv d2d4 e7e6 e2e4 d7d6
info depth 4 seldepth 4 multipv 3 score cp 7 nodes 642 nps 160500 tbhits 0 time 4 pv e2e3 d7d5 d2d4 e7e6
info depth 5 seldepth 5 multipv 1 score cp 50 nodes 2484 nps 310500 tbhits 0 time 8 pv b1c3 f7f5 d2d4 e7e6 d4d5
info depth 5 seldepth 5 multipv 2 score cp 28 nodes 2484 nps 310500 tbhits 0 time 8 pv e2e3 d7d5 d2d4 g8f6 b1c3
info depth 5 seldepth 5 multipv 3 score cp 22 nodes 2484 nps 310500 tbhits 0 time 8 pv e2e4 e7e6 d1e2 d7d5 d2d4
info depth 6 seldepth 6 multipv 1 score cp 13 nodes 4812 nps 401000 tbhits 0 time 12 pv e2e4 d7d5 d1e2 e7e6 d2d4 g8f6
info depth 6 seldepth 6 multipv 2 score cp 0 nodes 4812 nps 401000 tbhits 0 time 12 pv b1c3 d7d5 d2d4 g8f6 e2e3 e7e6
info depth 6 seldepth 6 multipv 3 score cp 0 nodes 4812 nps 401000 tbhits 0 time 12 pv e2e3 d7d5 d2d4 g8f6 b1c3 e7e6
info depth 7 seldepth 7 multipv 1 score cp 22 nodes 7301 nps 429470 tbhits 0 time 17 pv e2e4 d7d5 d1e2 e7e6 d2d4 d5e4 e2e4
info depth 7 seldepth 7 multipv 2 score cp 8 nodes 7301 nps 429470 tbhits 0 time 17 pv d2d4 d7d5 d1d3 g8f6 b1c3 e7e6 e2e4 f6e4 c3e4 d5e4 d3e4
info depth 7 seldepth 7 multipv 3 score cp 8 nodes 7301 nps 429470 tbhits 0 time 17 pv b1c3 d7d5 d2d4 g8f6 d1d3 e7e6 e2e4
info depth 8 seldepth 8 multipv 1 score cp 31 nodes 13100 nps 485185 tbhits 0 time 27 pv e2e4 d7d5 e4d5 d8d5 b1c3 d5a5 d1e2 e7e6
info depth 8 seldepth 8 multipv 2 score cp 4 nodes 13100 nps 485185 tbhits 0 time 27 pv b1c3 d7d5 e2e4 d5d4 c3b5 e7e6 e4e5 b7b6
info depth 8 seldepth 8 multipv 3 score cp -11 nodes 13100 nps 485185 tbhits 0 time 27 pv d2d3 d7d5 e2e4 b8c6 e4d5 d8d5 b1c3 d5a5
bestmove e2e4 ponder d7d5

```

---

Instead the output I want is only the last depth reached:

```
info depth 8 seldepth 8 multipv 1 score cp 31 nodes 13100 nps 485185 tbhits 0 time 27 pv e2e4 d7d5 e4d5 d8d5 b1c3 d5a5 d1e2 e7e6
info depth 8 seldepth 8 multipv 2 score cp 4 nodes 13100 nps 485185 tbhits 0 time 27 pv b1c3 d7d5 e2e4 d5d4 c3b5 e7e6 e4e5 b7b6
info depth 8 seldepth 8 multipv 3 score cp -11 nodes 13100 nps 485185 tbhits 0 time 27 pv d2d3 d7d5 e2e4 b8c6 e4d5 d8d5 b1c3 d5a5
bestmove e2e4 ponder d7d5

```

Any ideas on how to do this?

# Answer
> 2 votes
I don't think it's possible unless you recompile the source code. It's very easy to do it at the source code; you'll just need to add an if-statement just before the PV is printed.

Otherwise, you can pipe the outputs to a text file and do a grep like this:

```
grep 'depth 8' output.txt

```

---
Tags: engines, uci
---


# Question
Title: Static exchange Evaluation (SEE) optimization
Implementing SEE extensively in my chess AI but can't seem to speed it up. Just using depth and MaxDepth. I'd like to add heuristics similar to negascout, quiescence, lazy eval. Maybe something like alpha beta. Trade off minimal accuracy for performance.

Another question is what to return "in check"

```
function _see(sq, fen, depth, maxDepth, color, chess) {
    "use strict";
    if (chess.fen() !== fen) {
        console.error("s fen/chess sync error");
        chess.load(fen);
    }

    if (chess.in_checkmate() || chess.game_over()) {
        return MATE;
    } else if (chess.in_check()) {
        return 0; // ????
    }

    var value = 0, moves, index, move_score, tfen, foo, bar;

    if (depth < maxDepth) {
        moves = chess.moves({
            square: sq,
            verbose: true
        });
        if (moves.length > 0) {
            counter.seeNodes = counter.seeNodes + 1;
            moves = _.chain(moves)
                //only captures
                .reject(function (e) {
                    return !e.hasOwnProperty('captured');
                })
                //material MVV
                .sortBy(function (s) {
                    return evalPiece(s.piece);
                })
                //captures LVA
                .sortBy(function (s) {
                    return -evalPiece(s.captured);
                })
                .value();
            //counter.sDepth = Math.max(depth, counter.sDepth);
            //counter.maxSDepth = Math.max(maxDepth, counter.maxSDepth);        console.error(JSON.stringify(moves));

            for (index = 0; index < moves.length; index += 1) {
                foo = chess.move(moves[index]);
                if (foo === null) {
                    console.error("see move generated error, aborting loop");
                    break;
                }
                tfen = chess.fen();
                value = Math.max(0, evalPiece(foo.captured) - _see(sq, tfen, depth + 1, maxDepth, -color, chess));
                bar = chess.undo();
                if (bar === null) {
                    console.error("see: bar=null");
                }
            }

        }

    }
    return value;
}

```

# Answer
> 1 votes
Your algorithm seems very wrong to me for SEE. It appears much closer to Quiescence Search instead.

* SEE is an unary tree. After finding a legal move, the SEE function returns. It doesn't need to check all possible moves for the best one; just one.
* You sort your moves in MVV/LVA order. Your ordering should just be on the least valuable attacking piece.
* You search all possible moves. SEE only searches captures on a square.

To answer your question of:

> what to return "in check"

SEE doesn't actually care about check. If you capture with your king and the opponent can capture with anything, then the value of the king should be large enough that `Math.max(0, evalPiece(foo.captured) - _see(sq, tfen, depth + 1, maxDepth, -color, chess))` has a greater score for not capturing with your king than capturing the king.

---
Tags: engines, programming
---


# Question
Title: Would it be a decisive advantage, if the opponent would not be allowed to castle?
Suppose, you play a normal chess game, with the only exception that the opponent is not allowed to castle, but you are.

Do you have a decisive advantage ?

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

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

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

There have been some who have dubbed this "Kaufman chess", and suggested it as a sort of long-time control Armageddon method (rather than two rapid games, then two faster games, then two blitz games, and finally a blitz Armageddon, as in the FIDE World Cup).
> 8 votes

# Answer
Castling is an important move that allows a player to put his king into the corner's safety. The rearrangement that occurs when a player castles is beneficial because the king usually finds increased safety, away from the dangerous centre files while the rook boosts its attacking potential by moving out of the corner. To explain how much of an advantage it gives to have your opponent not being able to castle, I will talk about some positional strategies that we can adopt to exploit the disadvantage of it.

Every player likes to control the centre, the strategy of central control is why you want your d and e pawns to come up to d3, e3, d4 and e4 squares and try and control d4 d5 e4 and e5 centre squares. This opens up the centre and if the king is unable to castle and go behind g or c pawn, this leaves him right behind the open pawn structure in the centre, while his opponent's king looks very safe behind the f g and h pawns.

So assume white is the one who is not allowed to castle, and black already has. White needs to think about counter attack on f, g and h files and wants to open the black king to create an attack, meanwhile his own king is already open while trying to control the centre by pushing his centre pawns. So here black gains the advantage of having more opportunities to create threats on the open white king and white now has to defend his own king and also think about creating access to black's king, so obviously white is in a much more difficult situation than Black. This is a great advantage that black gets off his opponent not being able to castle (and the reason why most openings include castling in it's book moves).

This can also be related to opposite side castling, where both sides are pushing their opposite pawns forward hoping to be the first to launch an attack (the Sicilian defence is one of the best example where this usually happens). After opposite side castling, both sides can also have their pawns in centre and fight for centre control. While the most important thing is that both can achieve equality in the center, they still don't have to worry about their king because if one player tries to start an attack on his opponent's king side, the other can start a counter attack. Consider the same situation in a position where white's king can not castle and is in e1, say whites pawns are on c2 d2 e3 and f2 protecting the king while the g and h pawns are marching forward to attack black's king. To achieve a successful attack white needs his major pieces to also support the g and h pawns, so not only most of white's pieces have to leave one corner of the board and come to the other, but white also has to give up the centre squares while supporting the corner. Meanwhile, black's minor and major pieces, which have access to the centre, help not only to attack white's King which is in e1, but can also defend his own king since the pieces which are in centre have more mobility and control many more squares than the ones that are in corner!

With proper play from the opening, a side which can castle will have the decisive advantage of an **early attack on the opponents king.**

However, there are a few instances where castling should be avoided. Some common reasons include:

1. If castling will expose your king to greater danger.
2. If your opponent’s most threatening pieces (especially the queen) have already left the board.
3. If your rook is supporting an important advance of a flank pawn.
4. If you have powerful tactics available immediately and castling will cost you the initiative.
> 4 votes

---
Tags: castling
---


# Question
Title: Software suggestions to make printed chess exercises for kids
I'm planning to create a bunch of printed exercises for kids of different levels. I am still searching online for ideas and software suggestion. I wonder how other coaches here have solved this problem. Which software did you use to make pages and pages of chess diagrams, say with little boxes below it for kids to enter the answer? Thanks!

ps: I have ChessBase. Researching about Latex, found something called Sribus (Although I'm yet to fully understand what it does). oh, and I don't code.

# Answer
> 2 votes
Possible ideas I found when I asked the question on Reddit r/chess

* Chessbase + Wordprocessing tool
* Lichess + Evernote clipper (or snagit, etc) + Word (Add +blog if you want the answers to be public)

Other useful links that were suggested as comments

---
Tags: coach, diagram
---


# Question
Title: What has been the difference between Kramnik and Anand?
Both players are above 40, but Kramnik is still rated #2 in the world and is rated close to 2800, whereas Anand's rating has steadily been falling. What has Kramnik done to get better with age, which Anand has not been able to do ?

# Answer
Anand is 5 and a half years older than Kramnik. If you go back 5 and a half years, you'll see that Anand peaked in 2011 with a live rating of 2817.

So the idea that Kramnik somehow kept his rating high in way Anand has not been able to is completely wrong.
> 4 votes

# Answer
The difference between Kramnik's and Anand's ratings is basically just noise. They have been trading places on the rating list for over 20 years. Less than a year ago (September 2015), Anand's rating was higher than Kramnik's by the same amount that Kramnik's is currently higher than Anand's.
> 0 votes

# Answer
Anand seems to play a lot more than Kramnik, and five years age difference in the 40s is a considerable difference. I don't think Harikrishna will be top 5.
> -2 votes

---
Tags: psychology
---


title: Understanding magic bitboard

text:
# Question
Title: Understanding magic bitboard
I have read a lot of stuff about magic bitboard but some stuff is not clear. A lot of authors say to create the move masks for the piece avoiding the border positions. So, for a bishop at `D3` the move mask would be this:

```
00000000
00000000
00000010
01000100
00101000
00000000
00101000
00000000

```

instead of this

```
00000000
00000001
00000010
01000100
00101000
00000000
00101000
01000100

```

They say this is good for convenience. I don't see how, but anyway, lets bear with this idea.

The problem is that, if we will avoid the border are, how will the move map for a hook at `A1` be? All zeros? The hook at `A1` will be like this:

```
10000000
10000000
10000000
10000000
10000000
10000000
10000000
11111111

```

but if we cannot have the numbers at the border it will be all zeros.

Is there another reason for that "avoid the border" rule? Is that OK if I forget that rule and make it to the border?

# Answer
> 2 votes
It's not about avoiding the border. It's about avoiding the last bit of the ray.

Given this:

```
10000000
10000000
10000000
10000000
10000000
10000000
10000000
01111111

```

(Note that A1 should be zero as the rook is unimportant)

You will note that along the first rank, if there is no piece on G1, then a rook can attack H1, regardless of what is on that square. This also applies along the A-file, where if there is no piece on A7, then A8 can always be attacked.

Because of this, we mask out the last bit of the ray, as we do not need to know what's at the end of the ray, producing this mask:

```
00000000
10000000
10000000
10000000
10000000
10000000
10000000
01111110

```

This produces a significant table reduction, as you need only 12 bits of occupancy to index the table, not 14.

---
Tags: software, bitboard
---


title: Chess.com rating vs FIDE rating

text:
# Question
Title: Chess.com rating vs FIDE rating
I've been playing on chess.com standard time (not blitz) for a while with a rating of around 1670, but my FIDE rating is still around 1600, still growing. Is there an actual conversion available for these ratings?

# Answer
I play blitz there every day for many hours. My rating periodically oscillates between 1850 and 2050, which is a span of 200 points. This has little to do with my varying strength because it depends mostly on which opponents I happen to run into. This phenomenon puts a certain constraint on your idea of a conversion table.

I added two more comments to this answer. See below.
> 4 votes

# Answer
There isn't, but I believe the general consensus on this question on chess.com's forums is that your actual ELO/FIDE rating should be lower than your chess.com rating after you get a decent amount of games on both.

I'm not really sure how much lower it should be though. Perhaps the forums on Chess.com hold the answer.
> 1 votes

---
Tags: rating, online-chess, fide
---


# Question
Title: Does three-player chess have any special tactics I should know about?
In chess, attacking the centre and using major pieces to support minor pieces to support pawns are common tactics. In three-player chess the game is more complex. Should I be taking the centre, knowing I will be attacked from both sides, or should I try to flank opponents? If two players team up against one for a couple turns, how can I prevent my teammate from launching a surprise attack against me? There is little research into the mechanics of three-player chess and I find it very interesting.

# Answer
Well, since an exchange between A and B is in the sole benefit of player C, your primary objective should be: avoid exchanges. How do you avoid exchanges in a normal chess game? Play an opening with a closed center (e.g. King's Indian, Ruy Lopez), or choose a modest setup (like the Hedgehog system). The less you're exposed, the better.
> 1 votes

---
Tags: strategy, tactics, chess-variants
---


# Question
Title: Would it be offensive to a chess coach to hire another titled player just to play training games with?
Say I have a chess coach, but I hire another titled player to play training games with. Would it be offensive or alright to do? Or they would they care as long as I'm paying them?

# Answer
You are the customer, therefore you can spend your time and money as you see fit.

From your coaches' point of view, they would prefer it if you didn't use the services of another player. After all, any professional who is paid on an hourly basis would prefer to have a monopoly on a revenue stream and work 100% of the hours that you are paying for. But that is your coaches' problem, not yours.
> 6 votes

---
Tags: etiquette
---


title: En Passant vs In Passing

text:
# Question
Title: En Passant vs In Passing
In Lasker's Manual of Chess (written 1932 or earlier) I have just read the phrase 'in passing' referring to the en passant capture. I wonder if this expression is old-fashioned or still in use. Basically, I am interested in whether I can say 'in passing' in spoken language and still be considered correct.

The image shows the exact context. The phrase is right below the diagram.

# Answer
> 13 votes
According to wikipedia:

> En passant (from French: in passing) is a move in chess.

As far as i can find, 'In passing' is the translation of the name of the move, however it is not actually spoken as 'en passant' is used instead.

One explanation for the appearance of this term is that Lasker, the author of the book, accidentally translated the word. According to this page, the original form of this manual was written in German, and Lasker re-wrote it in English at a later date. He may have translated 'En Passant' into English by mistake, not realising that we also use the french for the term.

> In 1926 Lasker wrote Lehrbuch des Schachspiels, which he re-wrote in English in 1927 as Lasker's Manual of Chess.

# Answer
> 7 votes
"In passing" is english for the french phrase "en passant." Just like "vis-a-vis" and "tete-a-tete" is acceptable as are "face-to-face" and "head-to-head." I consider using the language of the listener to be the best course of action. All are correct, but since I teach to kids, I prefer the english.

# Answer
> 3 votes
Lasker originally wrote in German and used the phrase *im Vorbeigehen* that was translated literally here. *Im Vorbeigehen* was the usual German term at Lasker's time, but nowadays it is mostly replaced by the French phrase *en passant*.

# Answer
> 2 votes
*en passant* does mean "in passing", but the English phrase is not generally used in our specialized chess sense; e.g. Merriam-Webster separates two senses of *en passant*:

> 1) in passing,
>
> 2) used in chess of the capture of a pawn as it makes a first move of two squares by an enemy pawn that threatens the first of these squares.

This is similar to the chess sense of "Luft" (where the English air/space/breath would not be understood as specifically in a chess context), and different from "Zwischenzug"/"Zwischenschach" which are entirely equivalent with their English translations "in-between move/check".

---
Tags: terminology, en-passant
---


# Question
Title: How could I have won this Q vs R+N endgame?
I was playing as White in this superior position when I decided to sacrifice my Queen for Knight + Pawn:

```
[FEN "8/2k1r1p1/5n2/5PK1/6PP/3Q4/8/8 w - - 0 46"]

 1. Qc3+ Kd8
 2. Qxf6 gxf6+
 3. Kxf6 Ke8
 4. g5 Rf7+
 5. Kg6 Ke7
 6. f6+ Kf8
 7. h5 Ra7
 8. h6 Kg8
 9. Kf5 Kh7
 10. g6+ Kxh6
 11. f7 Kg7
 12. Ke6 Ra6+
 13. Ke7 Ra8 0-1

```

My thoughts were that the 3 far advanced, connected pawns would beat the rook, but I was wrong.

My question is: **what is the best move and plan in the starting position shown?**

# Answer
Partial answer - a Nalimov tablebase says your queen sacrifice should have resulted in a draw. Black cannot withstand your pawnroller and goes for a perpetual/stalemate combo. Your fatal mistake was `9. Kf5`

```
[FEN "6k1/r7/5PKP/6P1/8/8/8/8 w - - 0 9"]

1.Kh5 (1.Kf5??) Kh7 2.g6 Kh8 3.f7 Ra5+ 4.Kh4 Rh5+

```

From the starting position, Stockfish recommended...

```
[FEN "8/2k1r1p1/5n2/5PK1/6PP/3Q4/8/8 w - - 0 46"]

1.Kg6 Nd7 (1... Nxg4?? 2.Qc4+ {Black can't hold the g-pawn and both white pawns will queen... it's a merciful mate in 17}) 2.Qc3+ Kd8 3.Qa5+ Kc8 4.g5 Ne5+ 5.Kh5 Nd7 {This shuffling moves shows that Black is out of ideas.} 6.f6 gxf6 7.Qc3+ Kd8 8.gxf6 Re4 9.Kg5 Re6 10.Kg6 Ra6 {Black could take the pawn, trading both his pieces for the Queen and a pawn. But then White Queens the h pawn. } 11.h5 Ra4 12.Kg5 Ra2 13.h6 Rg2+ 14.Kf5 Rh2 15.Kg6 Rg2+ 16.Kf7 Rh2 17.Qa5+ Kc8 18.Ke7 Nb8 19.Qf5+ Kb7 20.Qb5+ Ka7 21.f7 Na6 22.f8=Q Rc2 23.Qf6 Rc7+

```

Yep, that's pretty computer-tactical. But what you see is White pushing the King away from the pawns, and then relentlessly pushing the pawns. As an aside, it would take quite a player to separate their King from the Rook without losing the Rook to a queen tactic. Not recommended!

Here's what Stockfish thinks about the sacrifice.

```
[FEN "8/2k1r1p1/5n2/5PK1/6PP/3Q4/8/8 w - - 0 46"]

1.Qc3+ Kd8 2.Qxf6 gxf6+ 3.Kxf6 Re4 4.h5 Rxg4 5.h6 Rg1 6.h7 Rh1 7.Kg7 Rg1+ 8.Kf6 {Draw by repetition.} )

```
> 6 votes

---
Tags: endgame, blunder
---


# Question
Title: Does Stockfish(and other chess engines) learn after an analysis? (is there a machine learning algorithm implemented in it?)
I was watching the Sinquefield Cup right now, in particular the game Svidler-Caruana. I analyzed once the position they got with Stockfish 7 64bit and it suggested the move Rf3. Svidler played instead Kg3, so i played it on Arena chess, and then i went back and re analyzed the same position, but this time the engine was suggesting Kg3. Is there some kind of machine learning algorithm implemented in the engines such that, when you go deeper in the game,they improve the analysis of previous positions?

# Answer
1. No, there is no machine learning implemented
2. Due to hashing, next time when you run the same analysis you might not get the same results
3. Some other much weaker engines do have machine learning implemented, but not Stockfish
4. See My question is about inconsistencies in Stockfish 7 outputs
> 4 votes

---
Tags: engines, stockfish
---


# Question
Title: How should black play to save this endgame?
Recently I've played a game (with blacks) which ended with this position (White to move) :

```
[fen "3rk3/p1R2ppp/2p5/8/P1K5/8/1P3PPP/8 w - - 0 1"]

```

It's clear that White player can't protect his pawns in the second row, but the problem here is with the a file, should black protect his pawns in the a file, which will quite restrict his possibilities ?
Otherwise, Is it possible to just abandon this pawn, and go for white pawns in the 2nd raw ? But the problem here is surely with the white pawn in a4 which is pretty advanced compared to black pawns.

How should black play in order to save his game ( a draw at least ?!)

# Answer
> 2 votes
This endgame is **lost** for black, but the best plan here is for black to enter 2nd rank and try to gain some pawns and throw some checks. White's plan on the other side is just to take a7 pawn and advance his a4 pawn till promotion

Good luck trying to SAVE that one

# Answer
> 2 votes
White to move in that position? It looks pretty lost for black. White should probably choose 1.Rxa7 to grab the pawn and retain the control over the vital seventh rank. I guess that blacks best option is to play 1...Rd2 to try to grab some pawns and get counterplay. White should probably keep the b-pawn and play 2.b4 and black should probably grab a pawn with 2...Rxf2. Then, white should try to promote the a-pawn as soon as possible. Black will then most probably have problems stopping this. When black sacrifices the rook for whites a-pawn, blacks f-pawn will be too far behind to be a problem for white. So my line goes

1.Rxa7 Rd2 2.b4 Rxf2 3.a5 Rxg2 4.a6 Ra2 5.Kc5 Rc2+ 6.Kb6 Rb2 7.Rb7 Rxb4+ 8.Kxc6 Ra4 9.a7 g5 10.Rb8+ Ke7 11.a8=Q Rxa8 12.Rxa8

and my guess is that white is winning since blacks f- and g-pawns are too far behind, while whites King is very active and can catch the pawns with Kc6-d5-e4-etc.

# Answer
> 1 votes
Black can't save the endgame if White plays well.

As Capablanca wrote in "Chess Fundamentals," a rook on the seventh rank is worth a pawn. Given that actual pawns are even, consider White a pawn ahead.

White will first capture the a pawn. Since there is no Black pawn on say, b6, White's a pawn is "passed." Such a pawn is worth two pawns. Now White has the value of three pawns (a whole piece), ahead, even though he has one extra pawn. He will move his b pawn to b4 while Black moves his rook to d2. Afterward, he will move his a pawn toward the queening square. Black has to move (and keep) his rook on the a file. White's king then picks up the c pawn because Black's king is confined to the seventh rank.

# Answer
> 0 votes
Stockfish agrees with the other posters. You can stick a fork in this one, it is done. Of course, it requires the opponent to find the right moves...

```
[FEN "3rk3/p1R2ppp/2p5/8/P1K5/8/1P3PPP/8 w - - 0 1"]

1.Rxa7 Rd2 2.b4 Rc2+ 3.Kd4 Kd8 4.a5 c5+ 5.bxc5 Rxf2 6.a6 Ra2 7.Kc4 Kc8 8.Rxf7 Rxa6 9.Rxg7 h6 10.Kb5 Rf6 11.h4 Rf1 12.g4 Kb8 13.h5 Rb1+ 14.Kc4 Rc1+ 15.Kd5 Rh1 16.Kc6 Ra1 17.Rg6 Ka7 18.Kc7 Rc1 19.c6 Rf1 20.Rxh6 Rf7+

```

# Answer
> -1 votes
What about

```
 .....   d8-d2
 c7-c8!  d2-e2!

```

Now it's possible to draw.

---
Tags: strategy, endgame, tactics, rook-endgame
---


title: Strategy behind this chess position?

text:
# Question
Title: Strategy behind this chess position?
I am only used to check-in-n type of puzzle, so I am quite lost when my friend challenge me to this endgame position. EDIT: figured out how to do the chess board (note: the board seemed to be flipped, the black pawn should be close to queening)

=====

Can Black win? Black move first.

```
[fen "8/7Q/7K/8/8/kp6/qp6/8 b - - 0 1"]

```

=====

It seemed very obviously that black should win, with an advantage of 2 nearly queening pawns. Yet the way the question is asked make me think otherwise.

# Answer
> 7 votes
According to the Nalimov Endgame Tablebase: http://www.k4it.de/?topic=egtb&lang=en this position is a win in 40 moves for black, if black promotes for a knight to block the upcoming avalanche of checks. However if black promotes for a queen it's a draw.

---
Tags: endgame, puzzles, queen-endgame
---


title: Black castling long in the Sicilian

text:
# Question
Title: Black castling long in the Sicilian
When and why does Black castle long in the Sicilian? What kind of strategies should both sides adopt in such games? What kinds of games does it give rise to, i.e. positional or tactical? Which players are well known practitioners of such as Black?

# Answer
> 6 votes
I found that the ECO B96 and B99 Sicilians include a line where Black castles long:

```

[fen ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6 7. f4 Be7 8. Qf3 Qc7 9. O-O-O Nbd7 10. Bd3 b5 11. Rhe1 Bb7 12. Qg3 O-O-O

```

This is not a popular move, and probably not Black's best move.

Here are 3 Master games. Black fares poorly, earning 1/2 out of 3.

Spassky v Fischer, 1972. Fischer barely saves a dead lost position by finding a draw by repetition.

```

[fen ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6 7. f4 Be7 8. Qf3  Qc7 9. O-O-O Nbd7 10. Bd3 b5 11. Rhe1 Bb7 12. Qg3 O-O-O 13. Bxf6 Nxf6 14. Qxg7  Rdf8 15. Qg3 b4 16. Na4 Rhg8 17. Qf2 Nd7 18. Kb1 Kb8 19. c3 Nc5 20. Bc2 bxc3  21. Nxc3 Bf6 22. g3 h5 23. e5 dxe5 24. fxe5 Bh8 25. Nf3 Rd8 26. Rxd8+ Rxd8 27.  Ng5 Bxe5 28. Qxf7 Rd7 29. Qxh5 Bxc3 30. bxc3 Qb6+ 31. Kc1 Qa5 32. Qh8+ Ka7 33.  a4 Nd3+ 34. Bxd3 Rxd3 35. Kc2 Rd5 36. Re4 Rd8 37. Qg7 Qf5 38. Kb3 Qd5+ 39. Ka3  Qd2 40. Rb4 Qc1+ 41. Rb2 Qa1+ 42. Ra2 Qc1+ 43. Rb2 Qa1+ 1/2-1/2

```

Pilgaard v Herrera, 2002 (white wins, the score isn't showing up)

```

[fen ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6 7. f4 Qc7 8. Qf3  Nbd7 9. O-O-O b5 10. Bd3 Bb7 11. Rhe1 Be7 12. Qg3 O-O-O 13. Bxf6 Nxf6 14. Qxg7  Rdf8 15. Qg3 b4 16. Nb1 Qa5 17. Nb3 Qxa2 18. Qe3 Kb8 19. Qb6 Nd7 20. Qxb4 Nc5  21. Nc3 Nxb3+ 22. cxb3 Rc8 23. Bc4 1-0

```

Parimarjan v Krishnan, 2011

```

[fen ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6 7. f4 Nbd7 8. Qf3 Qc7 9. O-O-O b5 10. Bd3 Bb7 11. Rhe1 Be7 12. Qg3 O-O-O 13. Bxb5 axb5 14. Ndxb5 Qb6 15. e5 Nc5 16. exf6 gxf6 17. Bh4 Rhg8 18. Qh3 Bxg2 19. Qe3 Bc6 20. Nd4 Bb7 21. Nf5 Bf8 22. Ng3 Rg6 23. Nge4 d5 24. Bxf6 Rxf6 25. Nxf6 d4 26. Qe5 dxc3 27. Rxd8+ Qxd8 28. Qxc3 Qc7 29. Nxh7 Qxf4+ 30. Kb1 Be7 31. b4 Be4 32. Ng5 Bxg5 33. Qxc5+ Kd7 34. h4 Bf6 35. h5 Bd5 36. Qb5+ Kd8 37. Qa5+ Kc8 38. Qc5+ Kd7 39. h6 Bd4 40. Qb5+ Kc7 41. Rf1 Qxh6 42. Rxf7+ Kd6 43. Qb8+ 1-0

```

This game is interesting because, statistically, `13. Bxb5` seems to be a refutation of `12. ... O-O-O`, with White winning 2 times as frequently as Black. The percentage of draws is low, so if you play this you better be ready!

`13. e5` may be an error with Black winning 2.5 out of the 3 games in the database. There are no master games with this continuation.

Look how Black's `g7` pawn falls in the first 2 games...

# Answer
> 6 votes
Black castling long in the Sicilian is a rare thing indeed. I can think of a few reasons:

* Black castling long is very rare in chess in general, only a few slow going openings (Caro-Kann, Scandinavian) feature it in general. It takes longer to prepare for long castling than for short castling, the king is less safe on c8 than on g8, white moves first so it's even riskier for black than for white.
* In the Sicilian, white generally gets quick development and an attack so it should be even more dangerous.
* Black has moved 1...c5, making the queenside less fit as a home for a king.
* Besides, one of the ideas of the Sicilian is to play along that c-file with a rook on c8, doesn't combine well with castling long.

So in general black only goes queenside if white has a full-force attack on the kingside and the center, and there is basically nowhere else to go.

I can think of one exception right now in the c3-Sicilian, where the queens are off the board and black can castle with check:

```
[FEN ""]

1.e4 c5 2.c3 d5 3.exd5 Qxd5 4.d4 Nc6 5.Nf3 Bg4
6.Na3 e5!? 7.dxe5 Qxd1+ 8.Kxd1 O-O-O+ *

```

and lines similar to that.

# Answer
> 1 votes
Normally, you don't want to castle "long" in the Sicilian because of the missing c pawn, which can make the king very vulnerable to attack.

An exception to this rule is when White has "wasted" a lot of moves on the king side, usually through a pawn "storm" *before* you castled. This would have given you time to get a center counterattack going. Then, castling long puts a rook on the d file which may be the coup de grace to White's center. More to the point, you will be able to "snipe" at White's exposed kingside pawns, and ultimately his king (which will probably be there, or in the center), without danger to your own king.

---
Tags: strategy, castling, sicilian-defense
---


title: Example highlighting overprotection

text:
# Question
Title: Example highlighting overprotection
Nimzovich was a proponent of the idea of over-protection, a concept which I don't understand well enough to ever implement in my games. Are there any example games at the GM level that illustrate this concept particularly well as a theme?

# Answer
The classic game that is typically used to explain 'excessive' protection is Aron Nimzowitsch vs A Giese (played in 1913)

http://www.chessgames.com/perl/chessgame?gid=1316457

pay attention to moves 10. Nf3! (first defense of e5) then 11. Re1! (second defense), and finally 13. Bf4! (third defense of e5)
> 2 votes

---
Tags: strategy, positional-play
---


title: Cmail/XBoard won't allow move

text:
# Question
Title: Cmail/XBoard won't allow move
I've recently started playing e-mail correspondence chess and I'm looking at Cmail/XBoard as a tool to play these games. Looking at the docs, I managed to get the right PGN tags for the game to be parsed and XBoard to launch and display the latest position.

XBoard will not allow any moves though. I can step through the game but not enter a new move.

Any idea on what could be wrong with the XBoard settings or the PGN input?

```
[Event "Email correspondence game"]
[Site "NET"]
[Date "2016.08.04"]
[Round "-"]
[White "Vergara, Rene"]
[Black "?"]
[Result "*"]
[WhiteNA "?"]
[BlackNA "email@host.com"]
[Mode "EM"]
[CmailGameName "rav-vs-Rene"]

1. e4
*

```

# Answer
> 1 votes
Once you provide the email file to Cmail/XBoard, you need to switch to 'Edit Game' mode, in the Mode menu in order to record a move. Also, I had to switch out of 'Edit Game' mode in order to mail the move.

---
Tags: correspondence-chess
---


title: Help me find this Lasker Chess quote

text:
# Question
Title: Help me find this Lasker Chess quote
I remember a few things from his saying - that he can produce a class A player out of an amateur in a span of so and so hours. I remember reading something along these lines, and I guess it's Lasker's quote, but my memory seems to fail me.

# Answer
Chapter "Final Reflections on Education in Chess"

page 373 in this pdf file:Lasker's Manual of Chess
> 4 votes

---
Tags: lasker
---


# Question
Title: Calculate the first N unknown moves of a chess game
Greetings fellow chess friends,

Here is a quick idea that came to my mind.

I am interested in writing a software that is able to **calculate and/or guess the first `n` *unknown* moves of a given chess game**. For example take this game:

1. ?? ??
2. ?? ??
3. Nf3 b6
4. g3 Ba6
5. Nbd2 Bb4
6. a3 Bxd2+
7. Nxd2 Bb7
8. Nf3 d5
9. cxd5 Bxd5
10. Bg2 O-O
11. O-O Nbd7
12. Bf4 c5
13. dxc5 1/2-1/2

You don't know the first two moves. Would it be possible to "calculate" them from the rest of the game and if yes, with what certainty? For example the move `9. cxd5` implies that a pawn has been placed on c4 earlier during the game.

Do you think this would be possible and if yes, for what maximum amount `n` of unknown moves?

Cheers

(Edit: corrected the 8th move, but need 6 characters to edit)

# Answer
Well, this should be semi-simple for a computer, at least. We know with absolute certainty that there are only 20 possible moves for both black and white (pawns and knights) on the first turn. After that, the only possible moves are moving the piece moved again, moving another pawn or knight, or moving a piece freed by the first move.

Knowing this, we can calculate the number of possible board positions after two turns. Luckily this has already been done here:

> There are 400 possible chess positions after two ply moves (first ply move for White followed by first ply move for Black). There are 5,362 possible positions (White’s second ply move) or 8,902 total positions after two ply moves each. There are 71,852 possible positions or 197,742 total positions after four moves.

This is a LOT, but it is possible to at least guess which one was used in the game.

The method I propose is to go though all of the movements of the game after the first four, but starting with the default chessboard as if the game had only just started. If a move occurs which is impossible, this indicates that this move has been made by a piece moved in the first two turns.

Despite this, there could be cases where a pawn moved on white's first turn and a pawn moved on white's third turn can take the same piece. If white takes with the pawn moved on the first turn, there would be no way to spot this, since you would assume the pawn moved on the third turn was used.

Sorry that this is only a half-answer; I will try to find more information to improve this.
> 2 votes

# Answer
The way I see it, there's no way to know for certain which order the moves were played in. For example, in the game you listed, it's not difficult to determine *what* the moves are. Following Aric Fowler's method, d4 and c4 for white and Nf6 and e6 for black are the moves. As for the order, however, there are four combinations:

1. d4 Nf6
2. c4 e6

1. d4 e6
2. c4 Nf6

1. c4 Nf6
2. d4 e6

1. c4 e6
2. d4 Nf6

Obviously, case 1 is the most likely, assuming the players know and follow basic opening theory, but I don't think there's any way to determine the order for sure.
> 1 votes

---
Tags: software, puzzles, annotation
---


# Question
Title: Where can I find collections of chess problems (ideally direct mate) with solutions?
I'm working on a chess program that gives the user various compositions for them to solve. So far I'm only including *mate in n* problems where 1 \< n \< 5, and I'd prefer to only deal with this particular type of problem, but the range is flexible.

I'm looking for any sources I can take problems from for my game without infringing on copyright or anything of that nature. The only other requirement is that the problems need to list their solution (ideally clear enough for the layman to understand). These could be sources that are in the public domain or ones that I can get written permission from the author(s) to use.

I've done some searching but haven't found many promising sources. The more problems available the better, but I need approximately 100+ problems in total, so ~33 for each problem type (mate in 2, mate in 3, mate in 4, etc.).

I'm hoping the community here can point me in the right direction.

# Answer
TheProblemist.org

> These direct-mate problems are chosen as a challenge to chess players who may be new to the world of composition. You should try to solve each problem before looking at its concealed solution. It may be helpful to look at the commentary or hints before revealing the solution.

**Edit:**

Chess.com has a great page of 10 puzzles with interactive chessboards. These are 'checkmate in one move' puzzles though, and are very easy.
> 3 votes

---
Tags: problems
---


title: Why not 4.Bd2 in the Nimzo-Indian?

text:
# Question
Title: Why not 4.Bd2 in the Nimzo-Indian?
After the initial moves of the Nimzo-Indian 4.Bd2 is rarely played and it gets poor results according to databases.

```
[FEN ""]
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Bd2

```

It looks like the most natural move to me, because:

* After Bxc3 Bxc3 White keeps the bishop pair and preserves the pawn structure.
* It breaks the pin, so the knight can influence the center again.
* It doesn't block any piece and it develops a piece.

And Bd2 is played against Bb4 in other openings.

So, why the move is weak?

# Answer
> 14 votes
There are really two questions here.

# Why is 4.Bd2 rarely played?

In a nutshell, 4.Bd2 is playable, but there are better alternatives.

> After Bxc3 Bxc3 White keeps the bishop pair and preserves the pawn structure.

Even if Black decides to reply with 4...Bxc3, White won't keep his bishop pair after 5...Ne4.

```
[FEN ""]
1. d4 Nf6 c4 e6 Nc3 Bb4 Bd2 Bxc3 Bxc3 Ne4 Qc2 Nxc3 Qxc3
(6. Bb4 c5 dxc5 Qf6 Nf3 Qxb2 Rb1 Qxa2)

```

> It breaks the pin, so the knight can influence the center again.

Black pins the knight to prevent White from playing e4. Even after 4.Bd2, White cannot do this.

```
[FEN ""]
1. d4 Nf6 c4 e6 Nc3 Bb4 Bd2 O-O e4? Bxc3 Bxc3 Nxe4

```

> It doesn't block any piece and it develops a piece.

But it leaves the pawn on d4 undefended and prevents the queen from defending the bishop if it develops to d3.

Let's look at the alternatives:

```
[FEN ""]
1. d4 Nf6 c4 e6 Nc3 Bb4 e3
(4. Qc2)

```

4.e3 (Rubinstein System) ignores the pin, prepares to develop the bishop to d3, protects the pawn on d4 and takes White one step closer to castling.

4.Qc2 (Classical Variation) is a better alternative to 4.Bd2 if you want to avoid doubled pawns at all costs.

# Why does 4.Bd2 get poor results according to databases?

As I said before, 4.Bd2 is playable. In fact, it's what Stockfish suggests after 3...Bb4. However, engines are particularly bad at openings and, as we have seen before, there are better alternatives.

Therefore, 4.Bd2 is mostly played by amateurs, which face the Nimzo-Indian and do not know the corresponding theory.

This makes the winning percentages in databases entirely useless. For example, according to 365Chess.com, White's first move with the highest winning percentage is 1.Na3.

# Answer
> 2 votes
Houdini 3 Extreme finds that 4. Bd2 promises White nothing more than dead equality at best. d2 is really not a very good square for the Bishop except to recapture on c3. The influence of White's Queen on the d file is effectively blocked when Bd2 is played. A simple line of defense such as O-O followed by d5 and b6 is sufficient for equality. In quite a few cases White does even get the two bishops after an exchange on c3 because of \____Ne4. Should White move his unpinned queen knight the Bishop will become a target of attack via Ne4.

---
Tags: opening, nimzo-indian
---


# Question
Title: Play chess in Python programming language?
I am searching for a program/library in Python which will let two users or a user and an AI play chess with each other.

PS: I have found python-chess. Can this be used for the above along with a chess engine?

# Answer
> 2 votes
Yes. You can use the package to play against yourself and an engine. While I don't think there is one function that can do everything for you, but I can give you hints:

To setup up a game against an AI:

* Read UCI documentation (you can find on Google)
* Read the UCI functions for python-chess here
* Spawn an engine thread by `engine = chess.uci.popen_engine("/usr/games/stockfish")`
* Start a new game by `engine.uci()`
* Send a move by `engine.position`
* Start analysis by `engine.go`
* Get engine results by `command.result()`

You will need to read the documentation carefully.

To setup a game against yourself (copied from the package documentation)

```
>>> import chess

>>> board = chess.Board()

>>> board.push_san("e4")
Move.from_uci('e2e4')
>>> board.push_san("e5")
Move.from_uci('e7e5')
>>> board.push_san("Qh5")
Move.from_uci('d1h5')
>>> board.push_san("Nc6")
Move.from_uci('b8c6')
>>> board.push_san("Bc4")
Move.from_uci('f1c4')
>>> board.push_san("Nf6")
Move.from_uci('g8f6')
>>> board.push_san("Qxf7")
Move.from_uci('h5f7')

```

# Answer
> 1 votes
You mentioned an AI. It might not be very strong, but sunfish is an example of a Python-based chess program, should you decide to go down that route.

Do also bear in mind that XBoard protocol is a valid option, using Polyglot by Fabien Letouzey to convert from UCI to XBoard. It is much harder to convert from XBoard to UCI, through something like WB2UCI by Odd Gunnar Malin, as XBoard is much more lax about things like thinking output.

I would recommend creating an account on the Computer Chess Club if you are going to create a GUI.

# Answer
> 0 votes
Cutechess cli ( https://chessprogramming.wikispaces.com/Cutechess-cli ) by Ilari Pihlajisto, is often used to run automated engine-engine matches. There is also work on a python port. ( http://www.talkchess.com/forum/viewtopic.php?t=60504 ) Github: https://github.com/lucasart/zinc

---
Tags: engines, software, python
---


title: What constitutes a chess ecosystem?

text:
# Question
Title: What constitutes a chess ecosystem?
I'm been thinking about the metrics to measure to make a "Best Cities for Chess" list. Assume I'm going to call these cities as "Chess Ecosystems", what are some of the things that would indicate its health?

ex: Number of FIDE rated players, tournaments organized every year, coaches available, etc.

What will you add to this list ?

# Answer
> 2 votes
The parameters I can think of:

Number of

* Chess club members
* FIDE rated players
* FIDE titled players
* Grandmasters
* Female players
* Tournaments
* Seminars / lectures

I'm not sure how to convert these parameters into a final score, nevertheless I'm curious how the list of best chess cities would look like. I would expect Moscow to be clear number one (many resident grandmasters, many tournaments). I'm also wondering how good Saint-Louis would score.

---
Tags: tournament, clubs
---


# Question
Title: Should beginners learn some boring drawn games first?
I recently studied the game Aronian vs Caruana in the Sinquefield Cup 2016, and I was absolutely delighted ! Unlike most GM games, it made total sense to me. I understood why the pawns were moved, why the bishops and knights were developed, how both sides had isolated pawns. I understood how the pressure slowly built around these isolated pawns and counted the number of defenders and attackers each side had around these pawns. I understood how the exchange took place, I understood how the pawns had to be placed on squares on the opposite colour as the opponents bishop and most importantly I understood why it was a draw (usually I don't) !

I was taken in by the beauty of the balanced positions and the web of Defense and attack.

Imagine my surprise when I saw their post match interviews. Aronian said he was not well, and although he was ashamed of the match was happy with the draw. Caruana said he jinxed it by saying that all his matches with Aronian have been interesting the day before, and that's why their match wasn't interesting.

Is this match considered boring because they played out old lines ? As a beginner it's new to me, and I actually understood it.

That's why my question is if beginners should first learn some of these standard boring lines so they can understand all the principles involved ? And if so, please recommend some sources where I can do that ?

The game mentioned above goes as follows:

```
rnbqkbnr/pppppppp/8/8/3P4/8/PPP1PPPP/RNBQKBNR b KQkq d3 0 1
1. d4 Nf6 2. c4 e6 3. Nf3 c5 4. e3 a6 5. Nc3 d5 6. cxd5 exd5
7. g3 Nc6 8. Bg2 Bd6 9. dxc5 Bxc5 10. O-O O-O 11. Nd4 Nxd4
12. exd4 Ba7 13. Bg5 Be6 14. Rc1 Rc8 15. Bxf6 Qxf6 16. Nxd5
Bxd5 17. Bxd5 Rxc1 18. Qxc1 b5 19. Qc6 Bxd4 20. Qxf6 Bxf6
21. b3 Rd8 22. Rd1 Kf8 23. Kf1 a5 24. Bf3 Rxd1+ 25. Bxd1 Ke7
26. a4 bxa4 27. bxa4 Bc3 28. Bb3 Bb4 29. Ke2 Kf8 30. Bc4
1/2-1/2

```

# Answer
> 3 votes
Yes understanding gm games is a very wonderful feeling. To understand many of the plans that occur in high level games I would suggest reading Pawn Structure Chess by Soltis. It's a book describing plans inherent in the position based on pawn structure, something all top GMs use in their games.

The reason why Aronian and Caruana considered this game boring is 2 fold. 1) the pawn structure was pretty much symmetrical. They each had a,b,d,f,g, and h pawns, and their d pawns were identically placed in the center. Their really aren't pawn structure plans in such positions, leaving a lot less resources to push your opponent around. Also it's a lot easier to create an advantage in a position with imbalances and asymmetry for both sides. 2) Secondly many of the pieces were exchanged when Aronian took on f6, leading to a very equal endgame with no chances for a win. Not to mention it was an opposite colored bishop ending, which are notoriously drawish.

Hope this helped!

# Answer
> 1 votes
Understanding any game is always beneficial to learning. The advantage of a drawn game is that neither side has the upper hand, requiring that they must attack and defend simultaneously. This is less prominent in games where one player is clearly outmatched either in skill or due to losing a piece. This allows you to consider attacks, counter-attacks, defense, and all manner of tactics for *both sides* and increases the complexity of the game in most cases.

Understanding games such as this is more beneficial due to them often involving complex board positions with simultaneous attacking and defending on both parts.

One disadvantage of studying drawn games is that most of the time the endgame is boring. Once the pieces are traded down, you often end up with a drawn-out and lengthy endgame where neither side can get any sort of advantage and end up making small moves of little significance. In this case, repetition is common and sometimes the 50 move rule is called upon. Despite this, some drawn endgames can be very interesting to study, however in most cases a drawn game is only interesting suring the opening and middlegame.

---
Tags: theory
---


title: How do you calculate elo?

text:
# Question
Title: How do you calculate elo?
I am starting a chess club at my school, and I want to create a Python program to calculate and store Elo ratings for each player. I am confident I can program it, but I just need to know:

**How do you calculate Elo?**

What i am looking for:

* Equations to calculate expected outcome for each player.
* Equations to calculate elo change using this.
* How to deal with a draw.
* How the value of K can be calculated, or suggestions for a static value of K which would work for students.

So far the best explanation I have found is the League of Legends rating system explained in this video (which happens to be the same system used in chess).

# Answer
Here you have some more information about Elo system that maybe it's useful for you.

Arpad Elo designed his system assuming a normal distribution in the results achieved by the players with a standard deviation of 200 rating points. So he used a logistic function to calculate the expected results by a player. The actual function (actually a table is used with minimal differences with this function) is:

```
WEa = 1 / (1 + 10^((Rb-Ra)/400)), rounded to two decimal digits

```

WEa is the expected result for player a, while Rb and Ra are the ratings of both players. As you can see in a game between two players having 400 points of difference in rating the chances of winning the game are 10:1.

After the game(s) expected and actual results of a player are compared, so players performing better than their expected results increase their ratings, and players performing worse decrease them. To do that the difference between expected and actual results is multiplied by a constant factor K. This constant value has to be small enough to make the system stable and avoid reflecting the very last results only, but large enough to be able to track players evolution. I guess a good value would be between 20 and 30, Jeff Sonas for example suggest 24 as the optimum value, while FIDE handbook points that rating stabilizes after 70 games (K10), 35 games (K20) and 18 games (K40), maybe these numbers can be useful for you to set your own K value.

Using a greater K value the very first few games can help your students to reach an approximate rating quickly and then you can change to a smaller K value.
> 9 votes

# Answer
All the informations regarding FIDE elo rating can be found here :

https://www.fide.com/fide/handbook.html?id=172&view=article

Each player must start with an estimated FIDE elo rating. Usually people are playing tournaments against FIDE players and then get a rating. (see article 8.2)

The FIDE elo system update your rating after each game played according to article 8.5.
> 2 votes

# Answer
Per https://en.wikipedia.org/wiki/Chess\_rating\_system

A player's new rating after a tournament is calculated :

```
Rn = Ro + (K/2)(W - L + (Sum of rating differences/2C))

```

Rn is the new rating, Ro is the old rating. W and L are the number of wins and losses. A rating difference is the opponent's rating minus the player's rating, not the other way around.

C will determine how spaced out the ratings are, i.e. the standard deviation. It appears that 200 is commonly used.

K will determine how much of an effect each game has. FIDE uses 30, and 20 once a player reaches IM. http://www.fide.com/component/content/article/1-fide-news/3963-rating-regulations-the-k-factor

A draw is 0 wins and 0 losses.
> -1 votes

---
Tags: rating, elo
---


title: Fritztrainer on Linux

text:
# Question
Title: Fritztrainer on Linux
What is the best way to use Fritztrainer DVDs/videos on Linux? Is there anyone who is using them on Linux now? Is there any free tool to run Fritztrainer DVDs natively?

# Answer
Over the years, this question has been asked several times on other forums, but I am not aware of a purely native solution.

According to this discussion on chess.com from 2013, some people have tried **Wine**, which is "a compatibility layer capable of running Windows applications on several POSIX-compliant operating systems, such as Linux, Mac OSX, & BSD" (quoted from the Wine website). People have reported varying levels of success, depending on the version of Wine and the distro they were using.

In an older discussion (started in 2009), someone suggested using **VirtualBox** and installing Windows in it. Unlike Wine, this requires Windows installation media and a Windows licence.

**Update**: Proton, released by Valve (the developers of Steam) in August 2018, should enable Linux users to run Windows games directly through Steam for Linux. Fritz XIV for Steam and FritzChess 15 for Steam have been available since September 2014 and February 2016, respectively. I don't know whether this also solves the issue of using the Fritztrainer DVDs.
> 4 votes

# Answer
Wine or Virtualbox, as already mentioned, use to be the options when you wish to run Windows programs on Linux. Wine use to be the best option but it can be a challenge and a pain sometimes to make it work properly with the desired windows application. There is a commercial alternative called Crossover which basically is Wine with some more user friendly configuration scripts etc. I don't know how much better than Wine it is but if you are interested there is a free trail you can try out there before bying.
> 1 votes

---
Tags: software, linux
---


# Question
Title: Bishop's opening - what's the point of 4. Qe2?
In Panov and Estrin's *Kurs debuytov* the following line is proposed in response to 3. d3:

```
[FEN ""]
1. e4 e5 2. Bc4 Nf6 3. d3 c6 4. Qe2

```

What's the point of 4. Qe2? Basically you should avoid moving the queen in the opening, which is the contrary here.

# Answer
> 8 votes
Black's main threat after 3... c6 is d5; it looks like Qe2 is an attempt to prevent that, by indirectly attacking pawn e5, even with check. However, I'm not so sure that it works as intended, because Black can play d5 anyway, e.g.

```
[FEN ""]
1. e4 e5 2. Bc4 Nf6 3. d3 c6 4. Qe2 d5! 5. exd5 cxd5 6. Bb5+ Nc6 7. Qxe5+ Be7 8. Nf3 O-O 9. Bxc6 bxc6 10. O-O Bd6

```

and Black's center control, slight development advantage and bishop pair provide more than enough compensation for the pawn.

I'd prefer a normal developing move (4. Nc3 or Nf3) instead of 4. Qe2.

---
Tags: opening, 1.e4, bishops-opening
---


# Question
Title: Have there been any simul round-robin games?
It occurred to me that it would be possible to have a match in which, say, each of 10 players play each other simultaneously twice. That is, if a regular simul match is a line of boards, this would be a grid, with each player playing black along one row, and white along a column. (The intersection of their row and column would obviously not be played...) Doing it online would simplify things a lot.

It seems like it would be a pretty interesting test of abilities, and solve the usual one-sided nature of simul matches.

Has this been done? What's the common term for it?

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

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

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

1. A - B
2. C - D
3. D - A
4. B - C
5. D - B
6. A - C

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

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

---
Tags: simultaneous
---


title: Is there any bughouse android app?

text:
# Question
Title: Is there any bughouse android app?
I want to play bughouse with my friend against other players, is there any android app that lets me team up with my friend and play bughouse?

preferably at our own pace, not the the fast bughouse that is played in tournaments, because we live in different timezones, he lives in australia, me in +3 GMT, and we have work so the probability of the two of us being online at the same time is so low

# Answer
> 1 votes
There exists "Yafi", which use FICS chess server, where you can play bughouse : https://play.google.com/store/apps/details?id=pl.mg6.yafi

# Answer
> 1 votes
We working on it. See doublechess server project in czech open bics article. http://bughousechess.wz.cz/BICS/CzechOpen/ or in http://bughousechess.wz.cz/BICS/index.html there is link. Its based on nodejs + chat + javascript. So far working ok from mobile or PC, any time for game and move clockssettings first beta. It is possible to run it over win or linux. There is now all time server running more or less. You welcome help us test,u can play on both boards also vs your friend or anybody. Now in test phase. PS. in yafi u cannot see and use pieces in hand easy. Dont mention u cannot play slower bughouse, only fast one. in bics and also in this dcb u can play delay=bronstein time for move control ie slower bughouse chess from any web browser even smartphone.

# Answer
> 1 votes
Android mobile app for bughouse online game with your friends: https://play.google.com/store/apps/details?id=ru.mail.park.bughouse

# Answer
> 0 votes
This isn't exactly what you are looking for, but I'd like to throw this out there for anyone looking for a Bughouse app that lets you play both boards on one device. It's far more suitable for tablets and other large devices, but definitely still playable on phones. Currently there is no support for using/connecting multiple devices, but this app is intended for groups of people who just want to use one device for all the boards.

https://play.google.com/store/apps/details?id=fhu.bughousechess

---
Tags: online-chess, online, websites, bughouse
---


title: Pawn-Promotions

text:
# Question
Title: Pawn-Promotions
The Pawn Promotion, I read that: "A pawn may be promoted to any piece. (NOTE: A common misconception is that pawns may only be exchanged for a piece that has been captured. That is NOT true.)" So, does this mean that if your queen hasn't been captured and you make it to the other side to promote your pawn, you can actually have, say, 2 queens on the board?

# Answer
> 3 votes
You may promote to a queen, a bishop, a knight or a rook of your own colour. Yes, you can end up with up to 9 queens in a game in principle.

---
Tags: pawn-promotion
---


title: Bughouse rating formula

text:
# Question
Title: Bughouse rating formula
Is there rating formula like ELO but for bughouse chess?

# Answer
Providing that teams are not fixed, Elo (and Glicko too) does not fit your needs, because it's designed for **1-on-1 matches only**.

You need something that manages both *team performance* and *players' rating*, as **TrueSkill** or **rankade**, our free-to-use rating system. Here's a comparison between aforementioned ranking systems.
> 3 votes

# Answer
Yes, you take the same formula and do absolutely the same calculations. Elo formula has very little to do with chess (except of it is used to calculate rating in chess). You can take any event that has win/lose/draw and apply elo formula to calculate the rating.

In bughouse you play in a team of two, so you will end up with a rating for a team.
> 4 votes

---
Tags: rating, chess-variants, bughouse
---


# Question
Title: What is the idea of the Kaufmann Attack (5.c4) against the Petroff?
What is the idea of White playing 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. c4 ? Does he intend to get some good version of the main lines, while avoiding certain sidelines? It seems in fashion now with games like this one, but I am not sure I grasp the full concept - Ian Nepomniachtchi vs Sanan Sjugirov, 2016

# Answer
In the main line 5.d4, black responds with 5....d5 in order to occupy the centre and to continue his development. The most popular line continues with: 6.Bd3 Be7 7.0-0 Nc6! 8.c4 Nb4! 9.Be2 0-0 (e.g. Nakamura-Akobian). Important to note: after 7....0-0 white has good chances to obtain an advantage after 8.c4.

With 5.c4 white wants to discourage black to play ...d5. After 5....d5 white seems to obtain an advantage with 6.Nc3. 6....Nxc3 is very dubious: 7.dxc3 Be6 8.Ng5 with a big advantage for white. Instead, black often plays 5....Be7. After 6.d4 0-0 7.Bd3 d5 8.0-0 white has successfully transposed to 5.d4 d5 6.Bd3 Be7 7.0-0 0-0 8.c4 (Nepomniachtchi-Wang Hao (blitz)).

However, black has better alternatives after 5.c4, for example:

```

      [StartPly "8"]

      [FEN ""]
      1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.c4 (5.d4 d5 6.Bd3 Be7 7.O-O Nc6 (7...O-O 8.c4) 8.c4 Nb4 9.Be2 O-O) 5...Be7 (5...d5 6.Nc3 Nxc3 7.dxc3 Be6 8.Ng5)(5...Nc6 6.d4 d5) 6.d4 Nc6 (6...O-O 7.Bd3 d5 8.O-O) 7.Bd3 Ng5

```
> 5 votes

# Answer
Just a tiny bit of history to explain the modern opening: It was Paul Morphy who started using the early ...Be7 and ...Nc6 which became the main line until the even more recent early Nc3 (without d4). However, Morphy had a penchant for ...f5 in many positions where it wasn't so wise, so 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be7 7. O-O O-O 8. c4 f5 was his idea of securing the center. Today's players avoid that unless they're aiming for Pillsbury's idea of ...Bg4 and only then ...f5.

All this is tossed out the window by Kaufmann (is it Larry Kaufmann?) who avoids all that.
> 0 votes

---
Tags: opening, petroff-defense
---


# Question
Title: Is there a way to watch blitz championship currently on chess.com on youtube?
Carlsen vs Grischuk: GM Blitz Battle Chess is currently being played on chess.com and being streamed on the chess channel on twitch.

My connection is very slow at the moment and I'm super busy and I'd like to watch previous matches especially the one that Carlsen played the other day. I have a free account on twitch and chess.com. Cess.com doesn't upload everything to youtube.

If they don't upload the video, is there any other way that I can watch the video?

# Answer
> 1 votes
You should be able to go to the Past Broadcasts section on Twitch. I believe there is a newish Twitch feature called Clips that you may want to check out. If someone created a clip of the match, it would save you having to rewatc

# Answer
> 2 votes
The stream from earlier today is available to be viewed here.

There will be another broadcast tomorrow, but that will be a separate stream, with a different link to view (and the link won't be available until tomorrow).

---
Tags: online-chess, online, online-blitz
---


title: Knight & Bishop vs. Queen

text:
# Question
Title: Knight & Bishop vs. Queen
All the articles I've read on the internet explain how a King, Knight, and Bishop should work together to defend against a King and Queen. This is called the Karstedt fortress.

This article depicts the fortress in the corner. My question is, assume the King, Knight, and Bishop are maintaining this defensive position in the middle of the board, or anywhere on the board except around the perimeter. Is there a way for the King and Queen to prevent or break down this fortress if it is not in the corner and force a win, or is this fortress strong enough to defend against a mate anywhere on the board?

If the King and Queen can force a win, how is that done?

# Answer
The Karstedt fortress must be set up in a corner. Even one square away it won't keep out the opposing King:

```
[Title "No fortress"]
[fen "6k1/5b2/7K/3nQ3/8/8/8/8 w - - 0 0"]

```

There is, however, a reverse fortress that keeps the stronger King imprisoned:

```
[Title "Draw"]
[fen "8/8/8/8/8/5nkb/2Q5/7K w - - 0 0"]

```

and even a mutual Zugwzang involving this configuration:

```
[Title "Mutual Zugzwang!"]
[fen "8/8/8/8/4k3/5n1b/8/2Q4K w - - 0 0"]

1.Qh6 Bf1!
2.Qc1 Bh3!

```
> 7 votes

---
Tags: endgame
---


# Question
Title: When and why should I trade minor pieces?
After looking at bishop placement and bishops compared to knights i came to the following question:

**When would it be beneficial to trade a knight for a bishop, or vice versa?**

This includes the following:

* Trading a fianchettoed bishop and a centralised bishop
* Trading a bishop of a particular colour and a bishop of the other colour
* Trading a knight and a bishop
* Trading an outposted knight for a bishop
* Trading a bishop for a centralised knight
* Trading two knights when one side would be left with a bishop while the other would be left with a knight
* Trading an undeveloped, or otherwise "out of the game" piece for a developed and active piece, both knights and bishops.

**How does the value of a knight or bishop change depending on the current situation in game?**

What examples are there of this? Why does this happen and how can I trade these pieces to my own advantage?

Example from GM (or other high level) games demonstrating one or multiple points would be greatly appreciated.

# Answer
## Guidelines of when to trade

> 1. First of all, you trade down when you're ahead in material. The more material that comes off, the bigger your advantage gets.
> 2. Next, you trade off when you have a spatial disadvantage. If your
> opponent is crunching down on you, by trading off pieces, you relieve the pressure on your position.
> 3. Third, **you trade when an exchange will make one of your surviving pieces more powerful**. For example, when trading bishop for knight, will leave you with a position with a very strong knight against a bad bishop of your opponent's.
> 4. And fourth, you trade when you'll be **getting rid of a very powerful piece of your opponent**.

From *Josh Waitzkin's Academy*, presented in the *Chessmaster* program. Emphasis is mine.

The remainder of this answer elaborates on points 3 and 4, i.e. you trade minor pieces when the resulting position is favourable to you, and the types of positions that favour the Knight or the Bishop are highlighted below.

## When a Bishop is stronger than the Knight

> Bishop and knight are of approximately equal value, but in the endgame, situations favouring the the bishop are considerably more common than those favouring the knight.

Why is this? Firstly, Bishops are stronger in open games, and endgames, with a large reduction in material, are often open.

Secondly, if play is on both sides of the board, then the bishop can cover both sides better than a knight can.

Here is an example:

```
[FEN "8/8/1k3b2/1p3p1p/pPp2P2/P1P3P1/8/1N2K3 w - - 0 1"]
[Site ""]
[White "Onoprienko"]
[Black "Khasangatin"]

  1. Kd2            Kc6
  2. Ke2            Kd5
  3. Ke3            Bg7
  4. Kf3            Bh8
  5. Ke3            Bg7
  6. Kf3            Bf6
  7. Ke3            h4
  8. gxh4           Bxh4
  9. Kf3            Bf6
 10. Ke3            Ke6
 11. Kf3            Kf7
 12. Kg3            Kg6
 13. Kh3            Kh5
 14. Kg3            Be7
 15. Kh3            Bh4
 16. Nd2            Be1
 17. Nb1            Bf2
 18. Kg2            Be3
 19. Kf3            Bc1
 20. Kg3            Kg6
 0-1

```

Here we see that:

1. White's pawns were locked onto dark squares, hence were targets for the Bishop
2. The Knight was entirely passive, guarding the Queenside pawns
3. The Bishop was able to triangulate to lose a tempo when White was in zugzwang. A Knight cannot do the same
4. Play was on 2 sides of the board, which is to the Bishop's advantage

Source for quote and example: *Understanding Chess Endgames* by John Nunn.

## When a Knight is stronger than the Bishop

> The Bishop doesn't always defeat the Knight. The Bishop's weakness, that it can only reach half the squares on the board, is exacerbated when it is a 'bad' bishop.

Let's take a look at an example:

```
[FEN "8/1p6/3p1k2/2pPp1p1/P1P1K1Pp/3N3P/3b4/8 w - - 0 1"]
[White "Nunn"]
[Black "Upton"]

  1. Kf3            Ba5
  2. Nf2            Bc7
  3. Ne4+           Kg6
  4. a5             Kh6
  5. Ke3            Kg6
  6. Kd3            Kg7
  7. Kc2            Kf8
  8. Kb3            Bxa5
  9. Nxd6           Bb6
 10. Ne4            Bd8
 11. Nxc5           b6
 12. Ne6+            1-0

```

Here we see that:

1. The position is closed, meaning White had time to maneuver the Knight to the ideal squares
2. The Bishop was hemmed in by it's own pawns and had no targets. It was effectively a spectator

Source for quotes and example: *Understanding Chess Endgames* by John Nunn.

## The Bishop pair

> Two Bishops are often a powerful force in the endgame. They have the long-range power of a single Bishop, but without the lone Bishop's weakness of only being able to reach half the squares on the board.

In this example, we see 3 themes as to how the Bishop pair can beat tBishop and Knight:

1. The long range of the Bishops means that whenever the Knight moves or makes a threat, then the Knight can be easily harassed or the threat can be parried
2. White's pawns are soon placed onto dark squares, whereas Black has a dark square Bishop. Black is playing with a passive, purely defensive Bishop
3. In the final position, the a3 Bishop dominates the Knight in one direction, i.e. the Knight cannot move to c1, b2, b4 or c5. In general, a Bishop separated by 2 squares like this dominates the Knight:

---

```
[FEN "7k/7p/p7/5B2/2b5/Pn2B2P/8/7K b - - 0 1"]
[White "Ye Rongguang"]
[Black "Nunn"]
[StartFlipped "0"]

1. Kg7 Kg2
2. Bd5+   Kg3
3. Na5 Bd4+
4. Kg8 Kf4
5. Nc4 Bc5
6. Kg7 h4
7. Kg8 Kg5
8. Ne5 Kf6
9. Nf3 Bf2
10. Bb3 Bg4
11. Bd5 a4
12. Nd2 Be1
13. Nf3 Bg3
14. Nd2 a5
15. Bc4 Be1
16. Nb3 Bc3
17. Nc5 Ke5
18. Nb3 Kd6
19. Kf7 Bh5+
20. Kg8 Kc6
21. Kf8 Bb4+
22. Kg7 Kb6
23. Kf6 Bg4
24. Nc1 Bc8
25. Nd3 Ba3  1-0

```

Source for quotes and example: *Understanding Chess Endgames* by John Nunn.

## The Exchange: Bishop vs Rook

> I must prepare you for the fact that we are not at all dealing with simple material here \[on the material imbalance of the Exchange in the endgame\]. There are preciously few general rules that can be formulated.

In the sections where I consider the exchange, it is important to think about whether a player would prefer to have Bishop vs. Rook or Knight vs. Rook. From the quote above, there are no guidelines *per se*. The positions require tactical analysis. However, a Bishop vs. Rook has better drawing chances than Knight vs. Rook. For example:

In this position White has built a fortress, and a draw is assured.

```
[FEN "8/8/p3kBp1/6P1/7r/1P6/1KP5/8 w - - 0 2"]
[White "Zuidema"]
[Black "Kostro"]

```

In this example of Knight vs. Rook, the outcome is a draw, but the Knight side has to work much harder for it.

```
[FEN "8/8/6R1/3k2P1/p2n4/2K1p3/8/8 b - - 0 1"]
[White "Smyslov"]
[Black "Fischer"]
[StartFlipped "0"]

1. a3             Ra6
2. Nb3            Rxa3
3. e2             Ra1  1/2-1/2

```

Source for quote and examples: *Van Perlo's Endgame Tactics, 2e*

## The Exchange: Knight vs Rook

> A firmly defended Knight or Bishop in the centre is only slightly weaker than a rook.

Quote attributed to Grigory Levenfish.

In the example below, we see Black's c5 Bishop and e5 Knight are so centrally dominant that White has to come up with an interesting exchange sacrifice to generate attacking chances. If White could swap minor pieces for the Bishop and Knight, then the game would be about even, but that is impossible to do immediately in the starting position.

```
[FEN "r4rk1/1pqb1ppp/p2ppn2/2b1nP2/3NP2Q/2NBB2P/PPP3P1/R4R1K w - - 0 1"]
[White "Mitkov"]
[Black "Rublevsky"]

  1. Rf3            Nxf3
  2. gxf3           Kh8
  3. Rg1            Qd8
  4. e5             dxe5
  5. Rxg7           Kxg7
  6. Bh6+           Kh8
  7. Bg5            Be7
  8. fxe6            *

```

Source for quote and example: *The Wisest Things Ever Said About Chess* by Andy Soltis.

## Miscellaneous ideas e.g. tactical considerations, outposts, Bishops of opposite colour etc.

Here I give a few examples of exchanging minor pieces under miscellaneous themes:

**Tactical considerations**

Of course, winning material, mating or converting into a won endgame take over all general considerations on when to swap minor pieces.

In this example, White enters a won King and Pawn endgame by creating some dangerous passers:

```
[FEN "8/1p3pp1/p1k1pn1p/P6P/2P3P1/2BK1P2/1P6/8 w - - 0 1"]

  1. Bxf6           gxf6
  2. f4             Kd6
  3. g5             fxg5
  4. fxg5           Ke7
  5. gxh6           Kf8
  6. b4              *

```

**Removing a defender of an outpost**

In this example, White eliminates the key defender of the d5 square, then pounds the backward pawn on d6:

```
[FEN "2rr2k1/p3q1b1/1p1pb1pp/4p3/2P5/1PN1Q1P1/P4PBP/2RR2K1 w - - 0 1"]

  1. Bd5            Kh7
  2. Bxe6           Qxe6
  3. Rd3            Rc7
  4. Rcd1           Rf7
  5. Ne4            Bf8
  6. Rd5             *

```

**Bishops of opposite colour as a drawing resource**

Here White is down 2 pawns, but by trading Bishop for Knight, a Bishop of opposite colour ending arises, which is usually a draw:

```
[FEN "8/4kp1p/Bp3np1/2p5/P2b4/8/3B2PP/5K2 w - - 0 1"]

  1. Bg5            Ke6
  2. Bxf6           Kxf6

```

Source for examples: *Practical Chess Exercises* by Ray Cheng.

## Summary

The decision on whether to trade Bishop for Knight is complex, but it depends on:

1. Tactical considerations, such as mating, winning material or forcing a won endgame
2. The Pawn structure - closed structure favour Knights, open favour the Bishops. Moreover, consider whether a Bishop has targets, i.e. enemy pawns on the same coour complex to attack
3. Piece activity - centralised minor pieces are worth close to a Rook's value in some positions
> 15 votes

# Answer
As you so amply put it: It depends.

It really is down to the how the pawns are placed. If you have all your pawns locked on white and you have a white-squared bishop, your opponent's knight can sit on a black square, be defended by a pawn and attack several pawns and your bishop at the same time, and there's nothing you can do about it. Obviously the knight is better.

If there are no pawns in the middle of the board, and the bishop can harass the knight from a distance, there's nothing the knight can do about it, and the bishop is obviously better.

There is a difference, though. It is sometimes possible to open a closed position. It is never possible to close an open position. And so in general, people prefer the bishop. Two bishops in an open position can be vicious.

If you have a closed position, you reckon there is no way it can ever be opened and you have a bishop of the 'wrong' colour, exchange it. ASAP. Doesn't really matter what with.

If the center is still mobile and you have ideas of opening it, exchange your knights for your opponent's bishop.

With the caveat of the exceptions. If your knight has a really good outpost (hard-to-attack or defended weak square in the opposing camp) use it. Oh, and if the exchange weakens a pawn structure in a non-repairable way, it's worth considering. Or if there are other tactical concerns, obviously.
> 2 votes

# Answer
> When would it be beneficial to trade a knight for a bishop, or vice versa?

Obviously, bishops are more interesting when there's an open position, where you can aim at long distance on the chess set along diagonals, with no pawns on your path. So the choice would be to avoid the exchange in such positions. In tighten positions, with entangled pawn structures, Knights however can be more effective. So I would keep them in that situations.

This is the *absolute* point of view, but depending on the game, you can find a specific utility to keep a knight in an opened position or not exchange a bishop in a closed one.

> How does the value of a knight or bishop change depending on the current situation in game?

I played a game recently when I had a good bishop, that I wanted to use for my attack, but then my opponent played his knight in a strategic place, where he would have made a lot of problems and have me lose my tempo because of a threat, so after evaluating the situation I decided it was better to make the exchange with my **(so good !)** bishop.

I would have preferred to keep it, but it was the position and the dangerous square occupied by the knight (that increased its value) that decided my move.
> 1 votes

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Tags: knights, bishops, fianchetto, trading
---


# Question
Title: Is it worth putting small kids in competitive chess?
I saw some chess tournaments with kids under the age of 7, and even under 5!
Surprisingly, including their performance.

Is adding the pressure of competition at this early age worth it?

# Answer
> 1 votes
it's no different than any other competitive activity, like soccer, or dodgeball, or anything where you have team vs. team or player vs. player.

It builds character, win or lose.

To learn how to lose is a skill that can only be taught by losing. Just don't make it a "win at all costs and we go to Applebee's" thing. That is the pressure you are talking about, and totally out of the realm of the player themselves - the child. They are unaware of it.

That is totally on you.

Don't live vicariously through your children to achieve the things you were unable to achieve. Encourage? Yes.

# Answer
> 1 votes
If the interest, competitive drive, and knowledge of the rules are there, then I wouldn't recommend against it. Even if they play competitively and find their talent for the game perhaps to be lacking, they can still take away much from the game, I feel.

Personally, I was pushed hard when I was young at the game (started at age 5, pushed relatively hard until about age 10), took a lackadaisical approach to the game as a rebellious result, but kept playing competitively through high school. I didn't do so bad, but not great either. What I took from the game though provided a niche for me for a time. Even if not used in any professional sense it can provide a potential life-long hobby. Even if it provides neither, denying them the opportunity given a desire to play competitively seems bad. It's just how one prepares.

Try and get an idea early of how good your child is. Playing with them a lot outside of tournaments first is a good way to do this. Then, you'll be able to gauge how hard to push them. If they're really good, push them just a little bit. If not, don't press them to play at all. Either way, if the desire remains to play and they're doing well in school, why not? I know I always had the desire to play competitively, and I'm glad in ways that I was pressed to play competitively.

---
Tags: psychology
---


title: Are mind games effective?

text:
# Question
Title: Are mind games effective?
If you want a quick match and need a way to put off your opponent early on, what sort of tactics can i use to mess with their head? I am specifically interested in the opening and middlegame, however answers regarding the endgame would also be appreciated.

I'm thinking about tactics such as alternating extreme attack and defense; making confusing moves to put off your opponent; playing with them and forcing them to move pieces to areas they do not want them in; disrupting their pawn chains and other defenses to make for an easier middlegame; piling up attackers on one square in particular, when in fact you are indirectly preparing for a strong attack on the opposite side (or even simply retreating and creating a stronghold around your king). I am also interested in direct body language such as making eye contact; showing a lack of emotion; and trying not to look like you are thinking hard, either to make the opponent think you are likely to make mistakes or to trick them into thinking you are completely confident with your position.

Answers may include:

* Addressing the strengths/weaknesses of a tactic, and how to perform it.
* Specific examples of any of these tactics in GM games
* Reviews on the use of such tactics and whether they are likely to work
* General rules of thumb in how to force moves or disrupt defenses
* Any tournament rules regarding mind tricks outside the game (either across the table or between games)
* Suggesting tactics not mentioned in the question above and giving reasons and uses

# Answer
Nigel Davies has a Fritz trainer DVD "chess for scoundrels" which works on this topic exactly. He shows some games and tells some anecdotes about how you can use mind games, to support your game (and he says that at GM level this is completely normal).

Examples by Davies: there was a Geller-Fisher game where Geller went for a drawing line with white, and offered a draw at move 7. Fisher laughed at his face (which is not so ethical imho) and then win in ~70 moves in a dead draw endgame, because Geller blundered. Bronstein in a draw or little worse position saw a trap, but was fairly sure his opponent would see it, he offered draw, suspecting his opponent will not take it (and it was fine for him), and went for the trap. His opponent declined, was searching for a win, and didn't notice the trap. I highly recomend buying the DVD, it's an amazing source in this topic.

People who were/are very good at this are for example Lasker, Tal, Fisher, Karpov, Kramnik. For examples read about the WC games Fisher vs Spassky, and Karpov vs Korchnoi with all the off board activities.

There was also a Benko book on psychology, but I didn't read it.
> 4 votes

# Answer
I recommend you to stick to the *principles* and don't hurry! Chess is naturally a slow game. It's better to go slowly but surely win.

Maybe you can try some opening traps, or prepared tactics, but if your opponent knows what to do, the counter-attack can *annihilate* you! Also, normaly traps don't have a 'plan b' if something goes wrong.

For example: Your idea of alternating between agressive/defensive only to mess with opponents mind may work sometimes, but there are no guaranties. If you are attacking, you put most (all?) your pieces in one side of the board, then stop the attack with no good reason and start to defend, your opponent probably *WILL* take the advantage and start his attack! And is much harder to be on the defender side! From that point on, he will start to put pressure as much as he can, and soon or later brake your defenses...

Also, I *strongly* recommend that you try your ideas against a good Engine. It will not forgive you, and will show every mistake you make and how your opponent can take advantage of it (and there is no psychology involved)!

Psychological tricks work better in poker than chess, but they can be useful. A tip that I heard from GM Igor Smirnov is: "You don't have to make 'the best move possible', but the one that create as much problems to your opponent to solve as you can find." I think this is a more realistic approach.
> 1 votes

# Answer
Psychology may play a part in high-level chess (top 100) when your opponents are known to you when you enter a tournament. For your Joe-Club player or week-ender tourney dude, it has no effect. Playing that game will surely lose fore you because you have decided to play sub-optimal moves for the position based on non-chess principles. That is just stupid chess.
> 1 votes

# Answer
Emanuel Lasker was famous for his psychological approach to the game. You may find some of his games in literature in which some of his moves are considered (were considered even at the time) inferior but his way of playing was indeed effective (search for his games against Capablanca to get an idea). However, as Rafael Borges pointed out, if your opponent plays very precise is very difficult to surprise him. Today with all the theory we have from the past, plus chess Engines (that are killing this "creative" approach to the game these days in my opinion) every little inaccuracy can turn out a complete disaster if your opponent is prepared (and most chess players today are able to play 30 moves of theory without doing any mistake).
> 0 votes

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Tags: opening, tactics, middlegame
---