The Windmill in Chess: discovered checks in a chain

The windmill is one of the most spectacular combinations in chess. When it’s executed, the opponent can only watch as their pieces disappear from the board one after another, unable to do anything about it. It’s the discovered attack taken to its maximum expression: not one, but a chain of discovered checks that sweeps everything away.

The mechanism: two pieces, an unstoppable cycle

Let’s see how it works. You need two coordinated pieces, usually a rook and a bishop. The bishop sits on a diagonal pointing at the enemy king, and the rook is positioned on that same diagonal, blocking the bishop’s attack.

Now the magic begins:

1. The rook steps aside from the diagonal, capturing an enemy piece. By moving, it reveals the bishop’s attack, delivering discovered check to the king.
2. The king is forced to move (it’s check, there’s no other option).
3. The rook returns to the diagonal, delivering direct check to the king. The king has to move again, usually back to the same square as before.
4. The rook steps aside again, captures another piece, and the bishop delivers discovered check again.

And so on. The rook goes back and forth like the blades of a windmill —hence the name—, capturing an enemy piece on every trip while the bishop keeps the king chained with constant checks.

Torre vs Lasker, Moscow 1925: the windmill’s immortal game

Want to see a real windmill? The most famous game featuring this tactic was played by the Mexican player Carlos Torre Repetto against former world champion Emanuel Lasker in Moscow, 1925.

Torre had his bishop on the diagonal pointing at Lasker’s king, and his rook ready to spring into action. What followed was devastating: Torre’s rook captured pieces on the seventh rank, gave check again, and the bishop completed the cycle with another discovered check. Lasker, one of the best players in history, could do nothing.

That combination became one of the most celebrated in chess history. All thanks to a windmill executed with surgical precision.

The ingredients of the windmill

What do you need for a windmill to work? Three elements:

1. A long-range piece on a diagonal or line toward the enemy king (usually a bishop, though it can be a queen). This piece stays fixed, delivering discovered checks every time the other piece steps aside.
2. A mobile piece that steps aside and returns (usually a rook). This piece does the dirty work: it captures material on every cycle.
3. The enemy king trapped. The king must have few escape squares and be forced to always return to the same position, allowing the cycle to repeat.

If any of these three ingredients is missing, the windmill doesn’t work. The king will find an escape square and break the cycle.

Variants of the windmill

Although the classic combination is rook + bishop, other variants exist:

• Rook + knight: the knight can substitute for the bishop delivering the discovered checks, though it’s less common because the knight needs more specific conditions.
• Queen + bishop: the queen plays the role of the rook, stepping aside and returning. It’s rarer because losing coordination with the queen is riskier.
• Partial windmill: sometimes you don’t need a full cycle. Two or three repetitions are enough to win decisive material.

How to spot a windmill

How do you know if you have a windmill available? Look for these signs:

• Your bishop (or long-range piece) points at the enemy king, but one of your pieces blocks the line.
• The blocking piece can move to a square where it captures material and can return to the blocking line delivering direct check.
• The enemy king has few escape squares and will be forced to return to the same position after every check.

If you see these three conditions, calculate the full sequence. Count how many pieces you can capture before the king finds an exit.

How to avoid falling into a windmill

The best defense against the windmill is not allowing it to form. Pay attention to these warning signs:

• An enemy long-range piece points at your king diagonally.
• Another enemy piece is on that same diagonal, ready to step aside.
• Your king has few escape squares.

If you spot that configuration, act before it’s too late: move your king off that diagonal, block the line with a defensive piece, or eliminate one of the two attacking pieces. Once the windmill starts turning, there’s no way to stop it.

Related tactics: The Discovered Attack · The Pin · Perpetual Check