Windmill — what it means in chess
A repeating sequence of discovered checks that harvests material.
A repeating sequence of discovered checks that harvests material.
The windmill is the most mechanical tactic in chess: a rook and bishop alternate discovered checks and direct checks, and each swing of the rook captures something. The defender spends every move answering check, so nothing can be defended, nothing recaptured, and nothing saved — pieces guarded three times fall exactly as fast as pieces guarded not at all.
[[board startfen="q4r1k/1p1nbpR1/8/8/8/8/1B6/6K1 w - - 0 1" pgn="1. Rxf7+ Kg8 2. Rg7+ Kh8 3. Rxe7+ Kg8 4. Rg7+ Kh8 5. Rxd7+ Kg8 6. Rg7+ Kh8 7. Rxb7+ Kg8 8. Rg7+ Kh8" caption="The windmill: discovered check, direct check, and a capture with every swing." notes="White to move. The rook on g7 and the bishop on b2 share the machine: whenever the rook leaves g7, the bishop's diagonal to h8 opens. Rxf7+ — the rook grabs a pawn, and its departure discovers the bishop's check. Black cannot recapture: answering the check is compulsory. Kg8 — the only square, attacking the rook — which does not care. Rg7+ — the rook returns with a direct check, back under the bishop's shadow. Kh8 — the only square again. The crank has turned once. Rxe7+ — swing two: a full bishop, taken with discovered check. Kg8 — as before. Rg7+ — the return stroke. Kh8 — the treadmill. Rxd7+ — swing three: the knight. Kg8 — nothing has changed. Rg7+ — again. Kh8 — again. Rxb7+ — swing four: another pawn, this one defended by the queen on a8. Defended, and it falls anyway — the queen cannot recapture while her king stands in check. Kg8 — still the only move. Rg7+ — the rook comes home. Kh8 — four swings: two pawns, a bishop, and a knight, and the Black queen watched every one of them, helpless."]]
The Endgame Society glossary defines more than 240 chess terms — rules, notation, tactics, strategy, pawn structures, endgames, and openings — in language a beginner can act on rather than dictionary shorthand.