Bishop and Knight Checkmate

The bishop and Knight mate is an obscure chess puzzle that hardly ever occurs in games. The puzzle is how to checkmate with just your King+Bishop+Knight vs the enemy King. With no pawns on the board. This is a fun puzzle, but it’s one of virtually no practical use.

The other similar checkmates are more useful and more likely:

  • King and Queen checkmate (basic checkmates)
  • King and Rook checkmate (K+R v K)
  • Two Bishops Checkmate
  • Two Knights Checkmate (not actually possible!)

The Bishop+Knight checkmate is theoretically possible. It’s extremely difficult to do it, and it takes about 40 moves or so. The theory is that you have to gradually corral the enemy King into the corner of the board, and it has to be the correct corner. The “correct” corner is the one where the corner square is same color as your bishop, so that the bishop can give checkmate at the end.

The phases of this checkmate are:

  • Push enemy King to the edge of the board.
  • The enemy King runs to the “wrong corner”
  • Gradually corral the enemy King along the edge of the board from the “wrong corner” to the “right corner”
  • Give checkmate with the Bishop

So good luck with that one. It’s tricky and takes ages. If you are defending it, now you know to run to the “wrong corner”. And there’s a high chance of stalemate.