King for the drive. The two pieces are not sufficient to confine
the opposing King to the corner. In Diagram 11 for instance, it
will be the best policy for White to advance right away with his
King in order to prevent Black's King from escaping into the
middle of the board. The following play might then ensue:

(1) K-b2, K-b7; (2) K-c3, K-c6; (3) K-d4, K-d6; (4) B-f5, K-c6;
(5) B-f4, K-b5; (6) B-e4, K-b4; (7) B-d3, K-b3; (8) B-d2, K-b2;
(9) K-c4, K-a3; (10) K-c3, K-a4; 11) K-c2 (not K-b2 which would
stalemate Black's King), K-a3; (12) B-b5, K-a2; (13) B-c1, K-a1;
(14) B-b2, K-a2; (15) B-c4 mate.

In the fight of King, Bishop and Knight against the King the mate
can be enforced only in a corner controlled by the Bishop, if the
lone King always makes the best move. Diagram 12 may serve as an
example of this ending. White has a black Bishop and so he will
have to drive Black's King to either h8 or a1 as it is not
possible to mate him in the white corner a8, unless he makes a
blunder.

After (1) B-e5 for instance, Black must of course not go into the
corner as Kt-b6 would mate him. He will play K-c8 and White will
have to prevent the flight of the black King into the middle of
the board. It is easy to see, by the way, that the Kt cannot be
placed so as to control the square c8, thereby forcing the King
into the corner, and to threaten the mate on b6 at the same time.
For he can control c8 only from a black square while he would
have to stand on a white square to be able to reach b6 in one
move.