“We recognize that and we want to be ahead of it.”The U.S. Open experimented with the serve clock during last year’s non-main draw events, like the qualifying and juniors competitions. But that clock was only seen by the chair umpire and the rule was rarely, if ever, enforced, especially against top players. Now an on-court clock will be visible to players and spectators alike, similar to the shot clock in basketball and the play clock in football. Last year, the U.S. Open also experimented with coaching from the stands in the non-main draw events, but that innovation, which is allowed in certain smaller tournaments, is not expected to be implemented for the main draw. I can adapt easily to that.”If the serve clock goes smoothly at the U.S. Open, the other three major tournaments — the Australian Open, the French Open and Wimbledon — could introduce it at their events in the future.

Source: New York Times April 11, 2018 23:49 UTC