Rules of Chess: The 50 Moves RulesOf the many questions I receive on the rules of chess, there is one that is most frequently asked:
If the king is your last piece is there a number of moves that the opponent has to check mate you??
The short answer to the question is: 50. That is: 50 moves of white and 50 of black. But the rule is somewhat more complex:
- It applies in more cases.
- Sometimes the count starts anew.
At a certain step in chess education, people learn how to win this position when they are white, but several players do not know how to win here, and keep moving the rook hence and forth, without actually mating the opponent. Consider also the following position:
Theoretically, this is a position that is won for white, but many players do not know (or have forgotton) how to win from this position.
To prevent players that do not know how to win have the game continue for ever, at a certain moment, a rule was made. The exact wording of the rule (9.3) is:
The game is drawn, upon a correct claim by the player having the move, ifThis rule gives the number: 50. This is 50 moves for white, and 50 moves for black.
- (a) he writes on his scoresheet, and declares to the arbiter his intention to make a move which shall result in the last 50 moves having been made by each player without the movement of any pawn and without the capture of any piece, or
- (b) the last 50 consecutive moves have been made by each player without the movement of any pawn and without the capture of any piece.
The rule says a little more:
- You can also claim a draw when you have more pieces left except your king if the 50 count is reached.
- The count starts at 0 every time a piece is taken or a pawn is moved.
The rule applies also when the weaker player has other pieces except the kingConsider the situation when white has a king and two bishops, black has a king and one bishop.
Looks like a good moment to agree to a draw. But perhaps white needs the win for the competition very badly, and he refuses a draw proposal offered by black. The advice for black is: start counting. Also in this situation, the 50 moves rule applies: when there are 50 successive moves without a piece taken (or pawn moved, but that cannot happen in this example), then a player may claim a draw. It seems unlikely that white can force a mate with this material...
When a piece is taken, the count starts again at zeroSuppose white has two knights and one bishop, and his king, and black has only a king.
Now, white should probably be able to win this game, but suppose he doesn't know how. If now, after the 43rd move of white after the position above, the following situation occurs:
Now, black can either take the bishop, which means that the count starts at 0 - white has another 50 moves to try to mate. Or he doesn't take the bishop, in which case white still has only 50-43=7 moves left... Hard choice, but not if you want to go home quickly.
When a pawn is moved, the count starts again at zeroConsider the following (somewhat implausible) position:
Now, this position will be rather hard to win for any player. White can last the game for quite some time, assuming black just moves his king hence and forth. If he moves after 49 moves his pawn one square ahead, the count starts at zero; something he can repeat once more later - say another 49 moves...
Can you win if your opponent cannot checkmate you in 50 moves, and all you have left is your king?
No. What you get is a draw: 1/2-1/2.
Written by Hans Bodlaender
WWW page created: January 14, 2002. Last modified: January 2, 2003.