Rules of chess the one nearest White's side of the board. Each square of the board, then, is uniquely identified by its file letter and rank number. The white king, for example, starts the game on square e1. The black knight on b8 can move to a6 or c6. In formal competition, each player is obliged to record each move as it is played in a chess notation in order to settle disputes about illegal positions, overstepping time control, and making claims of draws by the fifty-move rule or repetition of position. Algebraic chess notation is the accepted standard for recording games today.
Bughouse chess when captured. In play over the board, a promoted pawn can be put on its side to indicate promotion. A pawn placed on the second rank may move two squares on its first move. Each player must keep the reserve or stock pieces on the table in front of the board, always visible to all players of the game. Bughouse chess is usually played with chess clocks to prevent players from waiting indefinitely for a piece. Clocks are placed on the outside so that each player can see both clocks. At the start of the game, the players with the