For every tennis player, the perfect serve is the holy grail. The serve is the most powerful shot in tennis, and the only one that the player has full control over. Great servers such as Pete ...

NEW YORK—For some in tennis ... The ATP’s two poster boys for slow play, Rafael Nadal and Novak Djokovic, won the first two Masters 1000 events with a serve clock, in Toronto and Cincinnati.

The second serve is not the first shot you think of when looking at a tennis player ... “Obviously he has a great motion. He’s tall so he gets extra margin...He’s got the guts to go for ...