Players on the clock in Open

ATP and WTA are tracking what competitors, spectators and TV broadcasters make of the new system. Reviews from players so far have mostly been positive or indifferent, although Serena Williams said she’s “not a fan of it at all.”

“You’re aware of it. You certainly look at it and notice it. I do think it’s a good thing,” said Andy Murray, a three-time major champion. “It’s one of those things in tennis that is so stupid: The players were sort of expected to sort of be counting to 25 in their head. ... How are you supposed to know how much timeyou’re actually taking?”

Wimbledon semifinalist John Isner and others noted they would step to the line to serve and still have plenty of time — sometimes 10 seconds or more — left, enabling them to catch their breath or think about how to approach the next point. “I didn’t feel rushed at all, by any means,” Isner said. “Maybe it can slowyou down.”

That might have contributed to one unintended consequence during the three men’s tournaments where clocks were used for qualifying and main draws: longer matches. It’s a small sample size, and, of course, it’s dependent on the particulars of individual contests — nearly 30 percent more matches went to 7-5 or a tiebreaker in the third set in 2018 than 2017 at those events. But third sets lasted an average of 5 minutes longer this year than last year. First sets were nearly 1½ minutes longer this year while second sets were a minute shorter.

Servers were warned 74 times and returners received nine warnings at the ATP and WTA tournaments with the clocks.

It’s possible this setup will become more widespread as soon as 2019; the ATP Board could consider that for the men’s tour during its U.S. Openmeeting.

The amount of time taken between points has been a subject of discussion in tennis for quite a while now, just as other sports are concerned about whether events that take too long are losing viewers in this age of short attention spans and competition for eyeballs (take Major League Baseball’s limits on mound visits, time between innings and movement towarda pitch clock).

“This just makes it a little more transparent, a little more visible,” U.S. Open tournament director David Brewer said. “North American fans are used to shot clocks. They actually expect this sort of thing.”

There already was a time limit in tennis, but it was entirely up to a chair umpire’s discretion, because no one — most importantly players, but also folks in the stands and TV viewers — knew exactly how many seconds had elapsed. Now it will be apparent to everyone, much like a shot clock in the NBA and college basketball or a play clock in the NFL and college football.