In this position the power of the Rook is demonstrated by the first move, R - R 7, which immediately confines the Black King to the last rank, and the mate is quickly accomplished by: 1 R - R 7, K - Kt 1; 2 K - Kt 2.
The combined action of King and Rook is needed to arrive at a position in which mate can be forced. The general principle for a beginner to follow is to
keep his King as much as possible on the same rank, or, as in this case, file, as the opposing King.
When, in this case, the King has been brought to the sixth rank, it is better to place it, not on the same file, but on the one next to it towards the centre.
2...K - B 1; 3 K - B 3, K - K 1; 4 K - K 4, K - Q 1; 5 K - Q 5, K - B 1; 6 K - Q 6.
Not K - B 6, because then the Black King will go back to Q 1 and it will take much longer to mate. If now the King moves back to Q 1, R - R 8 mates at once.
6...K - Kt 1; 7 R - Q B 7, K - R 1; 8 K - B 6, K - Kt 1; 9 K - Kt 6, K - R 1; 10 R - B 8 mate.
It has taken exactly ten moves to mate from the original position. On move 5 Black could have played K - K 1, and, according to principle, White would have continued 6 K - Q 6, K - B 1 (the Black King will ultimately be forced to move in front of the White King and be mated by R - R 8); 7 K - K 6, K - Kt 1; 8 K - B 6, K - R 1; 9 K - Kt 6, K - Kt 1; 10 R - R 8 mate.
