Batteries
Two pieces lined up on one line hit the same square twice, and the one behind backs up the one in front.
The idea
Two pieces lined up on one line hit the same square twice.
- The queen on d3 attacks the pawn on h7.
- The bishop on c2 stands behind her on the same diagonal.
- Qxh7 is mate, because the bishop guards the queen.
In a game: Look for two of your pieces on one line, aimed at a square next to the enemy king.
How the lesson begins
A battery is two pieces lined up on one line and aimed the same way: a queen and a bishop on a diagonal, or two rooks, or a queen and a rook, on a file or a rank. The piece behind backs up the piece in front.
Here White’s queen and bishop make a battery aimed at h7, with the queen in front. The queen on d3 attacks the pawn on h7, and only the king guards it. Once she takes, the bishop on c2 guards her, so the king cannot take back. Qxh7 is checkmate.
- 12. Qxh7#
Find the move
Two rooks on one file are doubled, and they make a battery too. White to move. Your rooks are doubled on the open c-file. Find the check that leads to mate.
A hint
Count the pieces that attack c8 and the pieces that guard it.
Show the answer
28. Rc8+
Rc8+. Count on c8: the rook there is attacked once, by the rook on e8, and defended once, by the rook on c1. Black’s only move is Rxc8, and then Rxc8 is mate. The front rook is given up, and the rook behind finishes the job.