A couple other ideas: don't hack the pawn moves, just change the promotion rules to allow for promotion on either side of the board. Or, don't hack the pawn mov

A couple other ideas: don't hack the pawn moves, just change the promotion rules to allow for promotion on either side of the board. Or, don't hack the pawn moves and don't change the promotion rules. If a pawn gets stuck on its own side of the board, the pawn acts as a blockade but runs out of moves. This means the only way to promote is to capture an opponent's piece.