Corner Mate
Corner mate is a mate in the corner, where the mating piece steps next to the king and the edge of the board takes the remaining escape squares. The queen steps next to the king, and the white king protects the queen, so the king cannot take it.
The finished shape
This is the finished shape. Corner mate is a mate in the corner, where the mating piece steps next to the king and the edge of the board takes the remaining escape squares.
FEN: kb6/pQ6/2K5/8/8/8/8/8 b - - 1 1
a b c d e f g h
8 k b . . . . . . 8
7 p Q . . . . . . 7
6 . . K . . . . . 6
5 . . . . . . . . 5
4 . . . . . . . . 4
3 . . . . . . . . 3
2 . . . . . . . . 2
1 . . . . . . . . 1
a b c d e f g hThe worked example
White plays the mating move here. The queen steps next to the king, and the white king protects the queen, so the king cannot take it.
FEN: kb6/p7/2K5/8/8/8/8/1Q6 w - - 0 1
a b c d e f g h
8 k b . . . . . . 8
7 p . . . . . . . 7
6 . . K . . . . . 6
5 . . . . . . . . 5
4 . . . . . . . . 4
3 . . . . . . . . 3
2 . . . . . . . . 2
1 . Q . . . . . . 1
a b c d e f g hHow to prevent it
Black plays a6 first. The pawn move opens an escape square, so the mate no longer works.
FEN: kb6/p7/2K5/8/8/8/8/1Q6 b - - 0 1
a b c d e f g h
8 k b . . . . . . 8
7 p . . . . . . . 7
6 . . K . . . . . 6
5 . . . . . . . . 5
4 . . . . . . . . 4
3 . . . . . . . . 3
2 . . . . . . . . 2
1 . Q . . . . . . 1
a b c d e f g hKey points
- The queen steps next to the king, and the white king protects the queen, so the king cannot take it.
- The worked example ends with Qb7.
- To prevent it, keep an escape square open and do not let the queen settle next to the king.
- Black plays a6 first. The pawn move opens an escape square, so the mate no longer works.
- Check every escape square before you play the mating move, because one open square breaks the mate.
Try it Yourself
Edit the code, then press Run.
Running is simulated · Rust Playground
Exercise
Find the checkmate in this position.