Smothered mate

A smothered mate is checkmate, meaning the king is attacked and no legal move can remove the attack. A knight gives the final check while the king's own pieces occupy or close its escape squares. What appears to be protection around the king becomes a cage.

The knight is particularly effective because it jumps over pieces. Its check cannot be stopped by placing a piece between the knight and the king. For the position to be mate, the king must also be unable to capture the knight, move to safety, or remove the checking piece with another defender.

The famous combination in which a queen is deliberately given up to force a rook onto the king's last open square is one route to the pattern, not part of its definition. Direct smothered mates also occur without that preliminary sacrifice when the knight can already reach the required square.

Not every knight mate in a corner is smothered mate. In a corner mate, other attacking pieces may control the exits even when the king is not surrounded by its own army. The defining feature of smothered mate is that the defending pieces are essential parts of the confinement.