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.
Example 2.
Since the Black King is in the centre of the board, the best way to proceed is to advance your own King thus: 1 K - K 2, K - Q 4; 2 K - K 3. As the Rook has not yet come into play, it is better to advance the King straight into the centre of the board, not in front, but to one side of the other King. Should now the Black King move to K 4, the Rook drives it back by R - R 5 ch. On the other hand, if 2... K - B 5 instead, then also 3 R - R 5. If now 3... K - Kt 5, there follows 4 K - Q 3; but if instead 3... K - B 6; then 4 R - R 4, keeping the King confined to as few squares as possible.
Now the ending may continue: 4...K - B 7; 5 R - B 4 ch, K - Kt 6; 6 K - Q 3, K - Kt 7; 7 R - Kt 4 ch, K - R 6; 8 K - B 3, K - R 7. It should be noticed how often the White King has moved next to the Rook, not only to defend it, but also to reduce the mobility of the opposing King. Now
White mates in three moves thus: 9 R - R 4 ch, K - Kt 8; 10 R - any square on the Rook's file, forcing the Black King in front of the White, K - B 8; 11 R - R 1 mate. It has taken eleven moves to mate, and, under any conditions, I believe it should be done in under twenty. While it may be monotonous, it is worth while for the beginner to practice such things, as it will teach him the proper handling of his pieces.