Monochromatic chess d2 and f2, the white king can move from e1 only with castling and then g1–h2–g3–... so the pawn on g3 cannot be white. In Bichromatic chess, the opposite restrictions apply. A piece on a white square must move to a black square and vice versa. Hence pawns cannot capture (or advance two squares) and bishops cannot move. Also, castling and "en passant" are impossible, and queens behave like rooks. Monochromatic chess Monochromatic chess is a chess variant with unknown origin. The initial board position and all rules are the same as in regular chess, except that pieces that begin
Null-move heuristic of chess positions where employing the null-move heuristic can result in severe tactical blunders. In these "zugzwang" (German for "forced to move") positions, the player whose turn it is to move has only bad moves as their legal choices, and so would actually be better off if allowed to forfeit the right to move. In these positions, the null-move heuristic may produce a cutoff where a full search would not have found one, causing the program to assume the position is very good for a side when it may in fact be very bad for them. To avoid using the