Even many chess experts and masters cringe at the thought of having to mate with only a King, Bishop, and Knight against a lone King. Unlike all of the mates you have already seen, the path to this checkmate is unforgiving. A single mistake can require that you start over. Little wonder why even strong players will take their time here!
The main mating pattern almost always occurs in the corner of the color of the Bishop. As it turns out, there's simply no way to force checkmate upon the lone King in the "wrong" corner or on the edge of the board. As it turns out, the best defence usually involves retreating towards the corner of the opposite color of the Bishop.
The following diagram illustrates the checkmate:
Notice that the Bishop actually delivers the mate in the corner, with the Knight and King covering the avenues of escape.
The mate with the Bishop and Knight usually occurs in three stages. First, the attacking side must drive the King to a corner. The defensive side cannot prevent giving ground, so the lone King usually heads to the corner of the color opposite to that of the Bishop.
The second stage involves the forcing of the lone King from the "wrong" corner to the "right" corner. Finally, the attacking side must deliver the mate.
The following endgame illustrates the mating technique. Click here to view the endgame.