> this almost means a queen, but a promotion to knight can also be useful So can a promotion to rook or a bishop, if for example promotion would cause a stalem

> this almost means a queen, but a promotion to knight can also be useful So can a promotion to rook or a bishop, if for example promotion would cause a stalemate, especially if you're in a zugzwang. Although such situations in actual real-world chess are _exceedingly_ rare, they make for a good puzzle material.