Lesson
White to move. Main line: 1. Qd5+ Kh8 2. Nf7+ Kg8 3. Nh6+ Kh8 4. Qg8+! Rxg8 5. Nf7#
Every move is forced. The check on d5 drives the king into the corner, the knight check on f7 begins the famous “windmill” between f7 and h6, and the double check on h6 is the key mechanism — a double check can never be blocked, so the king must return to h8.
Then comes the point: Qg8+!! The queen gives itself up on a square defended only by the rook. After ...Rxg8 the king is completely smothered by its own pieces — pawns on g7 and h7, rook on g8 — and Nf7 is mate with the whole black army watching.
Note the defensive try 2...Rxf7, giving up the exchange instead of allowing the smother. It loses more slowly: the back rank collapses after Qd8+. Showing that refutation is what turns this from an animation into an explanation — the variation plays automatically in the shared replay.
If 2...Rxf7: 2... Rxf7 3. Qd8+ Rf8 4. Qxf8#
Philidor’s legacy
The pattern is old enough to carry a traditional name — Philidor’s legacy — and it is the most satisfying mate in chess: the king is surrounded entirely by its own pieces, and a knight delivers mate because a knight is the only piece that does not care about the wall.
The mechanism is a queen sacrifice that forces a friendly piece onto the king’s last free square.
Forced from the first move
This is not a trap or a practical try. Stockfish confirms mate in five from the starting position, and every move in the recorded line is the engine’s top choice: Qd5+, Nf7+, Nh6+, Qg8+, Nf7#.
Black is never given a decision that changes anything. That is what separates a forced mating net from an attack — there is nothing to defend against because there is no choice to make.
Recognizing it in your own games
The ingredients are specific: an enemy king on g8 or h8 with pawns on g7 and h7, a rook on f8, and a knight able to reach f7 or h6 with check. When you see that shape, look for the queen sacrifice on g8.
The double check by the knight is what makes the whole thing work — a double check can only be answered by a king move, so no interposition or capture saves Black.
1.Qd5+: Mate in five, and the engine’s first choice. 1.Qb3+ transposes to the same mate.
Every subsequent move in the line: Also top choice — the sequence is entirely forced.
Quiet alternatives such as 1.h4: Still winning on material, but they let Black keep playing. The point of the pattern is that it ends the game.
A double check can only be met by moving the king — no capture and no block.
The king’s own pieces are the mating net. Look for mates where the defender has too many pieces, not too few.
A queen sacrifice that forces a specific recapture is the standard way to fill the last flight square.
Source: Smothered mate — https://en.wikipedia.org/wiki/Smothered_mate