Federer needs to improve his ground game if he is to win Wimbledon again. Although his serve has been working, which is obviously the most important shot on grass, but he can't became another Isner. He has to try to break serve.
Federer vs Stakhovsky pretty interesting match tied at 1set all 2 tiebreaks and beginning of the 3rd Federer made 2 really big forehand UEs which cost him getting a break