Castling Castling Castling is a move in the game of chess involving a player's king and either of the player's original rooks. It is the only move in chess in which a player moves two pieces in the same move, and it is the only move aside from the knight's move where a piece can be said to "jump over" another. Castling consists of moving the king two squares towards a rook on the player's first , then moving the rook to the square over which the king crossed. Castling may only be done if the king has never moved, the
Null-move heuristic null-move heuristic in zugzwang positions, most chess-playing programs that use the null-move heuristic put restrictions on its use. Such restrictions often include not using the null-move heuristic if Another heuristic for dealing with the zugzwang problem is Omid David and Nathan Netanyahu's verified null-move pruning. In verified null-move pruning, whenever the shallow null-move search indicates a fail-high, instead of cutting off the search from the current node, the search is continued with reduced depth. Null-move heuristic In computer chess programs, the null-move heuristic is a heuristic technique used to enhance the speed of the alpha-beta pruning algorithm. Alpha-beta pruning speeds