rules, tactics, strategies and history

Checkmates

Considering that the object of the game is the capture of the opposing King, it seems most important to find out whether there are positions in which this capture can be accomplished in the face of the best possible defense. Naturally a player must have a certain material superiority to be able to force a mate, and the first question which offers itself is what MINIMUM force is required to compel the surrender of a King whose pieces have all been captured during the game.

It is clear that in order to checkmate the lone King it is necessary to attack the square on which he stands as well as all adjacent squares to which he could escape. The most unfavorable position for the King is, of course, a corner of the board as there he has only three squares to go to while in the middle of the board eight squares are accessible to him. Consequently, in an ending in which one player has only a King left the other player will try to drive the King into a corner where they need control over only three additional squares.

It can easily be seen that this can be done without difficulty with King and Queen or with King and Rook. Supposing, for instance, White has a King on c3 and its Queen on h3 while Black's King stands on d6 as shown in the following diagram.

								8
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								1
a	b	c	d	e	f	g	h

How will White proceed in order to drive the King into a corner and checkmate him there?

If White had a Rook on h3 instead of the Queen, the mating process would take a few more moves, but there would be no escape for Black either.

The two examples discussed show that it is not necessary to drive the King into the corner but that he can be mated on any square of the edge by Queen or Rook. It will be observed that in the mating position three of the six squares at Black's disposal are controlled by White's King and the other three by the Rook (or the Queen). If White had only a Bishop or a Knight in addition to the King he could never mate Black, for neither Bishop nor Knight can attack the King and at the same time control a square adjacent to the King. This, however, is at least necessary to force the mate, even in the most unfavorable position of the King, that is, in the corner.

								8
								7
								6
								5
								4
								3
								2
								1
a	b	c	d	e	f	g	h

There are possibilities of a player mating its opponent with only King and Knight or King and Bishop, but then there must be a piece of the opponent blocking the escape of the King.