Discovered Attacks

A discovered attack happens when you move one piece out of the way, revealing an attack from a piece behind it. It's like opening a door — the piece that moves is the door, and the piece behind it is the attacker.

Discovered attacks are devastating because they create two threats at once: the piece you moved can attack one target, while the piece you revealed attacks another.

Discovered Check

The most powerful form is a discovered check. The revealed piece gives check to the king, which must be answered immediately. Meanwhile, the piece you moved can do almost anything — capture a queen, threaten mate, or grab material — because the opponent has no time to respond to it.

Discovered check is sometimes called the most powerful move in chess because the moving piece has total freedom.

How to Spot Them

Look for this pattern:

1. Alignment. One of your pieces is on the same rank, file, or diagonal as the enemy king (or another valuable piece), with one of your own pieces in between.

2. The blocking piece can move usefully. If the piece in the way can capture, give check, or create a threat when it moves, you have a discovered attack.

3. The revealed attack is strong. Ideally, the piece behind delivers check or attacks an undefended piece.

The Windmill

The most spectacular discovered attack pattern is the windmill (or seesaw). This happens when the moving piece gives check, then returns to its original square, allowing the discovered check to happen again. The cycle repeats, winning material on each turn.

Famous windmill combinations have won games by capturing three or four pieces in a row, because the opponent must answer check each time and can never deal with the other threats.

Setting Up Discovered Attacks

Discovered attacks don't appear by accident. To create them:

Place a long-range piece behind a shorter-range one. A rook behind a knight, or a bishop behind a pawn, creates the potential for a discovery.

Open the position. Discovered attacks need open lines to work. Trade pawns to create open files and diagonals.

Look for batteries. A 'battery' is two pieces lined up on the same line (like queen behind bishop on a diagonal). When the front piece moves, the back piece fires.

Try It Yourself

In the puzzles below, look for a piece that's blocking a line of attack. Move it — and watch the fireworks.