Question: Sometimes one player is way ahead, and it seems like the match is over. Then the other player somehow comes back and actually wins. I saw that once in a match where Borg defeated Tanner. What is it that made him win?

He had the will to win and he refused to surrender. Most of the time Borg plays a defensive game, and so many times he wins. Therefore, he has confidence that his opponent will eventually get tired and not be able to attack him anymore. It is like a boxer who lets his opponent keep on hitting him. He knows that after a while the opponent will become tired and lose confidence. Similarly, if the other player strikes the ball hard ten times, and you keep on returning it, your opponent's determination will go away and he will give up.