Rafael Nadal was an unstoppable force at Roland Garros.  He had little to prove marching almost flawlessly to his record 10^th title but he did prove one thing…tennis needs a serve clock.  Whether you find Rafa’s routines amusing or exasperating, his serve prep violates the rules of the sport almost every time.  We know and he knows that officials are not going default him, at least not until his star wanes and he is less relevant in the slams.  This is completely unfair to opponents who abide by the rule and it gives him a competitive advantage. In defense of the umpire, it is a very subjective rule and rather difficult to enforce on a consistent basis.  Wouldn’t any sport prefer to avoid such subjectivity (please take note girls high school lacrosse)?  Clearly you cannot eliminate the rule or matches would take too long, so the answer is obvious.  Institute a serve clock.  Here’s how it could work:

1. At the start of a set and on changeovers the umpire starts the serve clock as soon as he/she calls time. 
2. After the first game and between even numbered games the umpire starts the serve clock as soon as all the tennis balls have been transferred to the opposite end of the court.
3. Between points the clock would be tied to the score, so that as soon as the chair umpire records the point the clock resets and begins running. 
4. The chair umpire would be able to stop the clock for external disruptions and could add 10 seconds back for a disrupted serve toss or if a player was disrupted with less than 5 seconds left on the clock. 
5. A time violation occurs if the serve clock expires before the player has tossed the ball (it must be completely out of their hand).  This would be fully verifiable by replay if it was ever decided that was necessary.
6. A time violation is recorded as a fault.

A change in this rule will not only improve enforceability and eliminate prevalent unfairness in the sport, it is my belief it will add urgency and excitement to the game for players and fans alike.