Chess lessons › Checkmate patterns
Mate with bishop and knight
A bishop and a knight can force mate, but only in a corner of the bishop’s colour.
The idea
Drive the lone king to a corner of your bishop’s colour, then mate.
- The bishop moves on light squares, so the mate needs a light corner.
- The black king is on h8, a dark corner, where no mate can be forced.
- So White drives it along the back rank to a8.
In a game: Before you start, look at your bishop’s colour and pick the corner that matches it.
How the lesson begins
A king and a bishop cannot checkmate a lone king, and neither can a king and a knight. A king, a bishop and a knight can, but the mate can only be forced in a corner of the bishop’s colour.
The bishop on e4 moves on light squares, so the mate must come on a8 or h1. The black king sits on h8, a dark corner, so White has to drive it along the back rank to a8.
This takes many moves. If fifty moves pass with no capture and no pawn move, the defender can claim a draw, so you need a method. Watch the start of it.
- 1. Nf7+ The knight checks, and the king goes to g8.
- 1... Kg8 2. Bf5 The bishop gets ready to take g8 away.
- 2... Kf8
A question
The bishop here moves on light squares. Which corner must White drive the black king to?
Show the answer
a8 or h1, the light corners.
Right. The bishop only ever reaches squares of its own colour, so it can only help to mate in a light corner.
In numbers
Positions to practise
16 positions in the study, every result proved by the tablebase: 16 are wins for the side to move, with best play on both sides.