 FACT: On the chess board shown at the beginning (and then again  later in the movie) the main character promotes the pawn to a knight  which both he and the computer claim is a checkmate for black. It  isnt a checkmate, since white can then take the knight with the  bishop. There is a mate in three for black (rook to g2, white is  forced to move the king into the corner, rook to a1, white is forced  to interpose the bishop, rook takes bishop = checkmate)