At Wimbledon, the Human Eye Keeps Dropping the Ball

Andy Murray was a victim.

Bianca Andreescu was too.

Jiri Lehecka had to play a fifth set and essentially win his third-round match twice.

Hawk-Eye Live, an electronic line calling system, could have saved the players their set, even their match, but Wimbledon doesn’t use it to its full extent, preferring a more traditional approach. The rest of the year on the professional tours, many tournaments rely exclusively on the technology, allowing players to know with near certainty whether their ball lands in or out because the computer always makes the call.

But when players come to the All England Club for what is widely regarded as the most important tournament of the year, their fates are largely determined by line judges relying on their eyesight. Even more frustrating, because Wimbledon and its television partners have access to the technology, which players can use to challenge a limited number of calls each match, everyone watching the broadcast sees in real time if a ball is in or out. The people for whom the information is most important — the players and the chair umpire, who oversees the match — must rely on the line judge.

When the human eye is judging serves traveling around 120 m.p.h. and forehand rallies faster than 80 m.p.h., errors are bound to happen.

“When mistakes are getting made in important moments, then obviously as a player you don’t want that,” said Murray, who could have won his second-round match against Stefanos Tsitsipas in the fourth set, if computers had been making the line calls. Murray’s backhand return was called out, even though replays showed the ball was in. He ended up losing in five sets.

No tennis tournament clings to its traditions the way Wimbledon does. Grass court tennis. Matches on Centre Court beginning later than everywhere else, and after those in the Royal Box have had their lunch. No lights for outdoor tennis. A queue with an hourslong wait for last-minute tickets.

Those traditions do not have an effect on the outcome of matches from one point to the next. But keeping line judges on the court, after technology has proved to be more reliable, has been affecting — perhaps even turning — key matches seemingly every other day.

To understand why that is happening, it’s important to understand how tennis has ended up with different rules for judging across its tournaments.

Before the early 2000s, tennis — like baseball, basketball, hockey and other sports — relied on human officials to make calls, many of which were wrong, according to John McEnroe (and pretty much every other tennis player). McEnroe’s most infamous meltdown happened at Wimbledon in 1981, prompted by an incorrect line call.

“I would have loved to have had Hawk-Eye,” said Mats Wilander, the seven-time Grand Slam singles champion and a star in the 1980s.

But then tennis began experimenting with the Hawk-Eye Live judging system. Cameras capture the bounce of every ball from multiple angles and computers analyze the images to depict the ball’s trajectory and impact points with only a microscopic margin for error. Line judges remained as a backup, but players received three opportunities each set to challenge a line call, and an extra challenge when a set went to a tiebreaker.

That forced players to try to figure out when to risk using a challenge they might need on a more crucial point later in the set.

“It’s too much,” Wilander said. “I can’t imagine making that calculation, standing there, thinking about whether a shot felt good, how many challenges I have left, how late is it in the set.”

Even Roger Federer, who was good at nearly every aspect of tennis, was famously terrible at making successful challenges.

Before long, tennis officials began considering a fully electronic line calling system. When the Covid-19 pandemic hit, tournaments were looking for ways to limit the number of people on the tennis court.

Craig Tiley, the chief executive of Tennis Australia, said adopting electronic calling in 2021 was also a part of the Australian Open’s “culture of innovation.” Players liked it. So did fans, Tiley said, because matches moved more quickly.

Last year, the U.S. Open switched to fully electronic line calling. There is an ongoing debate about whether the raised lines on clay courts would prevent the technology from providing the same precision as on grass and hardcourts. At the French Open and other clay court tournaments, the ball leaves a mark that umpires often inspect.

In 2022, the men’s ATP Tour featured 21 tournaments with fully electronic line calling, including stops in Indian Wells, Calif.; Miami Gardens, Fla.; Canada; and Washington, D.C. All of those sites have women’s WTA tournaments as well. Every ATP tournament will use it beginning in 2025.

“The question is not whether it’s 100 percent right but whether it is better than a human, and it is definitely better than a human,” said Mark Ein, who owns the Citi Open in Washington, D.C.

A spokesman for the All England Club said Sunday that Wimbledon has no plans to remove its line judges.

“After the tournament we look at everything we do, but at this moment, we have no plans to change the system,” Dominic Foster said.

On Saturday, Andreescu became a casualty of human error. The 2019 U.S. Open champion from Canada, Andreescu has been going deeper into Grand Slam tournaments after years of injuries.

With the finish of her match against Ons Jabeur of Tunisia in sight, Andreescu resisted asking for electronic intervention on a crucial shot the line judge had called out. From across the net Jabeur, who had been close to the ball as it landed, advised Andreescu not to waste one of her three challenges for the set, saying the ball was indeed out. The match continued, though not before television viewers saw the computerized replay that showed the ball landing on the line.

“I trust Ons,” Andreescu said after Jabeur came back to beat her in three sets, 3-6, 6-3, 6-4.

Andreescu explained that she was thinking of her previous match, a three-set marathon decided by a final-set tiebreaker, during which she said she “wasted” several challenges.

Against Jabeur, she thought, “I’m going to save it, just in case.”

Bad idea. Jabeur won that game, and the set, and then the match.

Over on Court No. 12, the challenge system was causing another kind of confusion. Lehecka had match point against Tommy Paul when he raised his hand to challenge a call after returning a shot from Paul that had landed on the line. His request for a challenge came just as Paul hit the next shot into the net.

The point was replayed. Paul won it, and then the set moments later, forcing a deciding set. Lehecka won, but had to run around for another half-hour. Venus Williams lost match point in her first-round match on another complicated sequence involving a challenge.

Leylah Fernandez, a two-time Grand Slam finalist from Canada, said she likes the tradition of line judges at Wimbledon as the world cedes more to technology.

Then again, she added, if “it did cost me a match, it would have been probably a different answer.”

That is where Murray, the two-time Wimbledon champion, found himself after his loss Friday afternoon. By the time he arrived at his news conference, he had learned that his slow and sharply angled backhand return of serve that landed just a few yards from the umpire had nicked the line.

The point would have given him two chances to break Tsitsipas’s serve and serve out the match. When he was told the shot was in, his eyes opened with a startle, then fell toward the floor.

Murray now knew what everyone else had seen.

The ball had landed under the nose of the umpire, who confirmed the call, Murray said. He could not imagine how anyone could have missed it. He actually likes having the line judges, he added. Perhaps it was his fault for not using a challenge.

“Ultimately,” he said, “the umpire made a poor call that’s right in front of her.”