"Out" With Electronic Line Calling in Tennis

Another moment in Cincinnati shows that live electronic line calling is still not up to the job it was entrusted to do in tennis.

MASON, Ohio — I have a few fun, in-depth stories I’m cooking up for y’all in the next couple days, but first I wanted to share a small-but-illustrative moment from last night here at the Cincinnati Open which I’m surprised barely got any attention.

Tommy Paul had set point at 6-5, 40-0 in the first set of his third round match against Adrian Mannarino, and hit a second serve which Mannarino returned.

And then…nothing happened? Paul thought the ball had landed out and poked his racquet into the court to say so; a few partisan voices in the crowd seemed to agree. Meanwhile across the net, Mannarino walked to the other side as if he had won the point. After all, there had been no “out” call to indicate that Mannarino’s shot had missed.

Here’s video of how the situation unfolded:

Chair umpire Fergus Murphy got on his walkie-talkie to the control room and said a video replay was on the way.

“Ladies and gentlemen, I am requesting a video review of the right baseline,” Murphy told the crowd.

A replay began to show on the big screen inside the Grandstand court. American fans shouted “out!” and “very out!” but Murphy didn’t seem as sure about the close call, saying that “I can’t say it on the screen” after the video began playing.

Murphy soon sided with the crowd: “Ladies and gentlemen, as you can see, the video review shows that the ball is out. Game, first set: Paul.”

Mannarino walked to the chair to complain about the ruling. Most of what Mannarino was saying was inaudible as the microphone near him wasn’t turned on, but he seemed to be arguing that the video was not conclusive: “We cannot see; no, we don’t even see the slow motion on the video.”

Murphy responded by telling Mannarino that he thought the ball was “about two inches out.”

There wasn’t a major outcry about this moment: Mannarino won the match in the end, and most of the tennis world seemed to be watching the simultaneous Jannik Sinner match instead. And maybe the delayed, jerry-rigged out call was right, ultimately.

But I was struck as I watched it: I had never before seen an “out” call determined by an umpire watching a video on a stadium screen replay like that. Why had this been necessary when electronic line calling was supposed to be doing such a flawless job, better than any human could?

After I inquired, the ATP sent this statement to Bounces explaining the incident:

VR [Video Review] can only be used for line calls when the system fails to track the ball and produce a decision, as was the case in the referenced incident. In this instance, the inability of ELC [Electronic Line Calling] to produce a decision was due to the proximity of the ball, racket head, and court surface at the moment of impact.

ELC’s “inability” to make a call would seem to fall into guidelines for video review for what happens when no call is made at all, as outlined in this document for chair umpires from earlier this year when the ATP first implemented video review at its 1000 events:

The CU [chair umpire] may call for a Video Review of a line call when there is no call from the Live ELC system (no audible call, no lights and confirmed from the RO [review official] there is no system result), and the CU cannot make the call. The result of the Video Review will not count against either player’s review count. The point will be replayed if the available video evidence is inconclusive.

But what would’ve happened if Tommy Paul had played the ball back and the rally had continued? Would no one have been the wiser?

When “In” and “Out” Flicker On and Off

The fallibility of the current line calling system has been on display several times in the last week or so.

Earlier that day in Cincinnati before Paul-Mannarino, a power outage that affected much of the tournament grounds forced a halt in play for about 75 minutes. (The ATP said that a power loss would not affect the marginal accuracy of electronic line calling: it would either be fully operative or fully inoperative.)

And late in the men’s side of last week’s Canadian Open in Toronto, there were several issues with the electronic line calling that disrupted play at length. First, the start of the second semifinal between Taylor Fritz and Ben Shelton—already a late start after the first match went to a third set tiebreak—was delayed by 15 minutes due to an electronic line calling outage.

Then in the Toronto final, a point had to be replayed twice because of a lack of audible calls on missed serves by Khachanov.

Midway through the second set, Khachanov clearly missed his first serve but there was no audible call, which confused both players.

Coincidentally, Fergus Murphy was also the chair umpire on this occasion.

“If it’s like two meters long, it doesn’t call,” Murphy explained to a confused Shelton.

Shelton, charitably, said Khachanov should get another first serve because his second serve had been unduly delayed by the conversation. But when Khachanov missed his redo and again no call came, Shelton began yelling: “That was this far out! Come on, man.”

Murphy agreed: “I know the ball is out,” he said, explaining to Khachanov “I know it’s out because I get a red light telling me it’s out. The problem was there was no call from the audio. So I know it’s out, but there’s just no ‘fault’ call.”

Both players were upset; Khachanov, understandably, was not a fan of silent, unspoken out calls.

“We are used to hear the ‘out,’ you know, like a linesperson,’” he said.

Murphy started radioing the control room for support.

Murphy: “Hello? Hello? I need some feedback, please.”

Review Official: “We have the lines working, but for some reason, there is no audio calls.”

Murphy: “OK, so we’re happy to continue like this for the moment?”

Review Official: “We don’t know for how long it’s going to take, but the system is up and tracking. But we are not sending audio calls.”

Murphy: “OK, well if we have the lights, that’s our procedure. If we have the lights, we keep going. So we just try and fix the audio.”

Review Official: “Thank you, Fergus.”

“OK, so everything is working, except the audio,” Murphy told the players, trying to reassure them. “The system is calling the balls in and out. I’ll get the lights; I’ll make the calls.”

Khachanov hit a ball toward a line to see if it would work; Murphy told them that wouldn’t work and the system would need to be set, but he was amenable to the idea of proving the function of the faltering system. The review official was more skeptical about this idea.

Murphy: “Before we start the players would just like to test, so I can get Karen to hit a serve, just test it, and everybody will be a bit more relaxed.”

Review Official: “We’re going to send a call…We don’t need the players to do [that].”

Murphy: “Alright, so…just tell me what to do then? We just have a bit of a credibility issue.”

Play continued after more than five minutes of delay. Khachanov, who had missed his first serve twice, was granted another first serve.

“If you want to give him another first serve again, that’s up to you,” Murphy told Shelton.

“Yeah, another first serve, why not?” Shelton said. “It’s Christmas!”

The players laughed it off and played on. but the scene should have been deeply embarrassing to tennis officials, especially in the final of a prestigious ATP 1000 event. To me, it was yet another exhibit of how rushed the implementation of this still-not-ready-for-primetime technology had been, as it was last month on Centre Court, too.

Calling Out for Humanity in Tennis

As they continue to pile up, these moments have shown that the new system just isn’t good enough to have been relied upon so wholly so hastily. Live electronic line calling chased human line judges off the court much faster than they should have under the guise of the pandemic; the old system, with skilled human line judges whose work was reviewable by a challenge system. Those challenge moments weren’t just good officiating, they added a bit of life and crowd participation into atmospheres as fans engaged and slow-clapped along; those moments, and how they showed the personalities of players, are now gone, replaced by a system with no personality whatosever. All the built-in moments of tension and excitement that close calls yielded—both in the Hawkeye challenge era and even in the old McEnroe meltdown era—have been flattened and erased in this new antiseptic, automated moment.

The easiest fix? Bring back humans and the old challenge system. Next best? The communication and display of out calls needs to be much, much clearer. Out calls should be clear and audible on every point, and there should be a visual signal as well that can easily be seen by players and audiences—in the stadium and on broadcasts—not just a small red light to which only the chair umpire is privy.

Right now, the current state of electronic line calling just feels like the current state of AI, being presented to us as credible and reliable when nearly anyone can tell it’s not yet up to the task.

Aside from all the people showing recently how ChatGPT can’t count how many times the letter ‘B’ is in ‘blueberry,’ I recently stumbled across a tennis example of this: I was wondering if anyone man had been younger than 17-year-old Richard Gasquet when he won a Grand Slam mixed doubles title, and so I Googled the topic.

Google AI confidently said it was 20-year-old Rod Laver, which I immediately knew it was wrong—but many others might’ve just taken at face value.

(The answer, I believe, was a 16-year-old Jimmy Arias.)

Adding to this feeling: even as I finish up this piece near an empty stadium during a Cincinnati rain storm, a disembodied voice just shouted “Foot fault! Foot fault!” into the night. These faceless voices are disconcerting when shouting amok, I must say.

Relatedly: on my drive to from DC to Ohio, I greatly enjoyed hearing my buddy Courtney Nguyen’s two-part visit to The Body Serve podcast, including a section about AI that Courtney deftly segued into a discussion of line judges (the part about line judges begins 40:45 into this episode).

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One more note, as a follow-up: I got several comments from folks on Sunday evening when Sofia Kenin played her first match since she was the focus of my vAce% story at Bounces last week.

She Can't Touch This

Sure enough, her opponent Varvara Gracheva hit 15 aces, good for an ace rate of 14.9 percent in her three set win. It was by far the most aces Gracheva had ever hit; only twice in Gracheva’s career had she even been above 10 percent.

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Thank you to all of you beautiful humans for subscribing to Bounces! -Ben