A Rook and a Bishop trap the enemy King using a series of discovered checks along an open file and diagonal, grinding down defenses until mate is forced.
Why it matters
The bishop delivers the check along the long diagonal, the rook covers the escape square beside the king, and the king's own pawn blocks the last one. Two pieces and a diagonal are enough.
It is worth knowing alongside Greco's mate because they are mirror images: there the rook mates and the bishop covers, here the bishop mates and the rook covers. Recognising which one you have decides which piece to bring first.
See it on a board
The bishop checks along a1–h8, the rook takes g8, and Black's own pawn on h7 removes the last square.
Checked: this line ends in checkmate.
How to play it
- Clear the long diagonal so a bishop can check the king in the corner.
- Cover the escape square next to the king — usually g8 — with a rook on the g-file.
- Check that nothing can interpose on the diagonal, then give the check.
At each level
The same idea, said the way it is taught at each age.
Rook · ages 6–9
A bishop checking a cornered king is mate if the square beside the king is covered and its own pawn blocks the other. Check both before playing it.
Queen · ages 8–11
The reason to know both this and Greco's mate is that the attacking setup tells you which piece to spend a move on: the file or the diagonal, not both.
What goes wrong
- Giving the check while a defender can block on the diagonal.
- Assuming the pawn on h7 is a weakness for Black — here it is, but a pawn on h6 instead would give the king a square.
Questions people ask
- How is this different from Greco's mate?
- The roles swap. In Greco's mate the rook or queen mates down the h-file and the bishop covers g8; here the bishop mates on the diagonal and the rook covers g8.