Smothered mate
Stockfish 16.1 · runs in your browserPlay Nf7#, then drag Black's king from h8 to g8. Black's own rook blocks g8, so the board refuses the move.
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Smothered mate is a knight checkmate in which the king's own pieces block its escape. Play Nf7# here: the black king cannot move because its rook and pawns occupy the neighbouring squares.
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A smothered mate is a knight check against a king boxed in by its own pieces. On this board Black's king sits on h8, its rook on g8, and its pawns on g7 and h7. Those friendly pieces occupy the squares the king would otherwise need. White's knight begins on d8. Play Nf7# and notice that a knight checks by jumping; Black cannot block its attack with a piece on a square between the knight and king. The king has no legal reply.
After Nf7#, try to drag Black's king from h8 to g8. The board refuses the move because Black's own rook occupies g8. The pawn on h7 closes another nearby square. Even if that rook moved away, the position would need to be checked again: a knight check by itself is not always mate. This example is the final mating net, not a sequence proving White could force the king into it from an earlier game position.
When you see a king in a corner, check the friendly pieces around it before hunting for a knight fork. Can the king step to a safe empty square? Can another piece capture the knight? Can the side in check make any legal move? Only when all replies fail is the knight move mate. The famous Philidor pattern can end with this shape after a sacrifice, but it has extra moves and conditions. Reset this board and name each blocked square before exploring that longer pattern.
Rules and examples
FIDE Laws of Chess, Article 5.1.1, governs mate; Wikipedia defines the smothered pattern.
Rules: FIDE Laws of Chess, effective 1 January 2023. https://handbook.fide.com/chapter/E012023
Rule replay: python-chess 1.11.2 (GPL-3.0-or-later). The shared browser engine retains its Stockfish GPL-3.0 notice. No engine score is claimed by these demonstrations.
Read the rulesA move on the board
3N2rk/6pp/8/8/8/8/8/K7 w - - 0 1
6rk/5Npp/8/8/8/8/8/K7 b - - 1 1
- Nf7#The knight checks h8; Black's own rook and pawns block the king's escape squares.
The knight checks h8; Black's own rook and pawns block the king's escape squares.
Original teaching example replayed with python-chess 1.11.2, 2026-10-23.
Analysis runs on Stockfish 16.1 in your browser, compiled to WebAssembly by stockfish.js. Stockfish is free software under the GNU General Public License v3; its source code is on GitHub.