By Martyn Herman
LONDON (Reuters) - A simple plaque next to Court 18 at Wimbledon records the 11 hours and five minutes it took American John Isner to beat Frenchman Nicolas Mahut in a three-day epic in 2010.
That record-breaking duel, which Isner won 70-68 in a deciding fifth set, is unlikely ever to be surpassed but, even without the occasional freak match, watching tennis is becoming an increasingly time-consuming activity.
The days when players like Pete Sampras and Boris Becker served and volleyed and points were over in a blur, are no more.
When Novak Djokovic played Andy Murray in this year's Australian Open final, the first set alone took 72 minutes.
Some of their rallies lasted longer than the time it takes to make a cup of tea.
A decade ago the average for a set was 40 minutes.
Even on Wimbledon's slick lawns match times have risen in the past decade, but it is not just game style that is elongating matches -- it is also what happens when the ball is not even in play.
Fourteen-times grand slam champion Rafael Nadal, most often cited for slow play, is not alone in fussy pre-serve routines.
Most players seem unable to play two points without toweling down while "bathroom breaks" at the end of sets have become almost routine, especially in women's tennis.
To think in the 1970s players still did not get chairs to sit on at changeovers, resuming battle after a swig of water.
Television has played it's part, with the 90-second changeover, the perfect time to screen commercials.
A more complex and gray area is the time taken for players to serve.
At Wimbledon players are allowed 20 seconds before serving -- not long when you have to grab a towel, adjust your shirt, tweak your shorts, choose a ball, bounce it numerous times (world number one Djokovic has been known to reach 15 bounces) and finally deliver.
Nadal seems to contravene the rule more than most, with umpires, who since 2013 can take away a serve for a second offense, now enforcing it more stringently.
"He touches his ears, he bounces a certain amount of times. He does the same thing every time. The poor guy, he's driving himself crazy," three-times Wimbledon champion John McEnroe, now a commentator with ESPN and the BBC, said.
What annoys players is the often random way the time rule is enforced by umpires -- a situation Andy Murray and others feel could be remedied by a "shot clock".
"How are players supposed to know, we can't know," Murray, who was warned for slow play at Roland Garros, said.
"Because are we supposed to be counting in our head?"
While time between points is something of a gray area, what is clear is that tennis matches are stretching.
Data complied by analyst Jeff Sackmann, who used match stats from 25 years of men's tennis, revealed that the average point in a men's match took 4.6 seconds longer in 2012 than in 1991.
Things have speeded up slightly since then and McEnroe believes that rather than pick on the likes of Nadal, the ATP and WTA should be cracking down on players leaving the court for bathroom breaks or calling on the trainer for tactical reasons.
"Why don't you focus on the people calling trainers, abusing the rule? To me, that's far worse," he said.
Fellow American Chris Evert agrees. Speaking on an ESPN conference call she said: "I have more of a problem with ‘I call a trainer because my heart is beating fast, I'm having a panic attack.’ You know what? You're nervous or you're out of shape.
"We see this in the women's game more than the men's. We see players sitting on the side waiting for 10 minutes then they come back and win the match.
"We didn't even sit down. We didn't even have chairs in the 1970s!"
(Reporting by Martyn Herman; editing by Toby Davis)