Roger won. But it wasn’t his best tennis. Or was it? He managed to fight off seven set points against Novak. He was having an off day, but still he won the crucial points. Everyone has a bad day in tennis, but some people seem to be able to make a silk purse out of a sow’s ear. As I was playing the other day, it struck me that (a) tennis is an incredibly difficult game to master and (b) if you do anything even slightly wrong you won’t hit the ball well. It has to be exact. Every shot has to be executed to perfection. There’s no margin for error. In philosophy, too, there’s no use in getting it a bit right. Any error, any sloppiness, and things go very wrong. Technique is all.