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
Late Move Reductions lead to a different search space than the pure alpha-beta method which can give different results. Care must be taken to select the reduction criteria or the search will miss some deep threats. Late Move Reductions In computer chess, and in other games that computers play, Late Move Reductions (LMR) is a non-game specific enhancement to the alpha-beta algorithm and its variants which attempts to examine a game search tree more efficiently. It uses the assumption that good game-specific move ordering causes a program to search the most likely moves early. If a cut-off is going to happen in a