X-ray
A piece that attacks or defends through another piece.
The idea
A piece attacks or defends through another piece on its line.
- The black queen has one defender, the rook beside her.
- White’s rook sees the same square, right through its own queen.
- So the queen takes, Black takes back, and White’s rook mates.
In a game: When you count attackers and defenders, count the pieces lined up behind them too.
How the lesson begins
An x-ray is an attack or a defence that works through another piece. White’s rook on e1 stands behind the queen on the same file. While the queen is there, the rook cannot see e8, but the moment she moves, it does.
Black’s queen on e8 is defended by the rook on d8. White’s queen can still take it, because the rook behind her supports the capture. Press Next move.
- 1. Qxe8+ The queen takes the queen with check.
- 1... Rxe8 Black takes back with the rook.
- 2. Rxe8# The rook on e1 now takes on e8. It was supporting the queen all along, through her. The king has no square: this is checkmate.
Find the move
White to move. The bishop on b2 stands behind the queen on the same diagonal. Find the checkmate.
A hint
The queen can take on g7, and the bishop will support her.
Show the answer
1. Qxg7#
Qxg7# takes the pawn with check. The king cannot take the queen, because the bishop on b2 now defends g7 through the square the queen has just left.
In numbers
In the puzzle bank
718 puzzles in GreyChess’s bank practise it. Half of them are rated between 1,144 and 2,183.
The piece that makes the first move of the answer: queen 57%, rook 23%, knight 8%, bishop 7%, pawn 5%, king 1%, in puzzles from the Lichess puzzle database.