WHITE.BLACK.
1.K to B 41.K to K 5
2.R to K sq.: ch.2.K to B 4
3.K to Q 43.K to B 5
4.R to B sq.: ch.4.K to Kt 4
5.K to K 4...

It will be noticed that the White King always approaches at the distance of a Knight's move, whilst the Black King moves either on diagonals, or takes the "opposition" to the White King.

...5.K to Kt 3
6.K to K 56.K to Kt 4
7.R to Kt sq.: ch.7.K to R 5
8.K to B 58.K to R 6
9.K to B 49.K to R 7
10.R to Kt 310.K to R 8
11.K to B 311.K to R 7
12.K to B 212.K to R 8
13.R to R 3, mate.

N.B.—The Rook can only checkmate on an outer row or file of the board.

KING AND TWO BISHOPS AGAINST KING.

To checkmate with two Bishops is comparatively easy. Fig. 19 illustrates the most unfavourable position for White, and the solution given is the shortest attainable.

WHITE.BLACK.
1.B to Q sq.1.K to K 6
2.K to Kt 22.K to Q 7
3.B to Q B 23.K to K 6
4.K to B 34.K to B 6
5.K to Q 45.K to Kt 5
6.B to K sq.6.K to B 6
7.B to Q 37.K to B 5
8.B to K 48.K to Kt 4
9.K to K 59.K to Kt 5
10.B to K B 210.K to Kt 4
11.B to K B 511.K to R 3
12.K to B 612.K to R 4
13.B to K 613.K to R 3
14.B to Kt 414.K to R 2
15.K to B 715.K to R 3