Top seed Alexander Zverev stirred controversy during his third-round match at the Madrid Open, when he paused play to photograph a disputed ball mark, challenging the accuracy of the Hawk-Eye electronic line-calling system. The incident, which earned him a warning for unsportsmanlike conduct, has tennis fans once again talking about the reliability of technology on clay. Let’s look at what actually happened and why it matters.
A Photo That Stopped Play
Zverev faced Spain’s Alejandro Davidovich Fokina in a tense third-round match at the Caja Mágica, ultimately winning 2-6, 7-6(3), 7-6(0). Zverev believed a backhand from his opponent landed wide but was called in by Hawk-Eye. Convinced of a “malfunction” in the system, he argued with umpire Mohamed Lahyani, who couldn’t overrule the electronic call. Frustrated, the German grabbed his phone from his bag and snapped a photo of the ball mark, prompting a warning from the umpire for unsportsmanlike conduct and some boo’s from the crowd.
Still, after the match, Zverev posted the photo on his Instagram story, captioning it, “Just gonna leave this one here. This was called in. Interesting call,” with two thinking emojis. The image, showing a mark Zverev believed was clearly out.
Clay courts historically rely on physical ball marks, inspected by umpires, due to the surface’s visible traces. However, the ATP and many WTA events, including Madrid, have phased out line judges this season, leaning on Hawk-Eye for speed and consistency. Doubts persist about its accuracy on clay, where sliding balls can distort marks. Zverev’s incident isn’t isolated, Aryna Sabalenka received a similar warning for photographing a mark in Stuttgart earlier this month, and Victoria Azarenka shared a disputed call image from Madrid on social media.
The upcoming Roland Garros event will stick with line judges, a decision many players support. Hawk-Eye’s clay record isn’t flawless; its error margin, though under 3mm, can be decisive in tight matches.
Technology’s role in tennis
Zverev’s photo sparked broader questions about technology’s role in pro tennis matches. Electronic systems like Hawk-Eye reduce human error but remove the usual ball-mark checks clay players seem to prefer.
Zverev’s decision to photograph the mark was bold but risky, getting him a warning that could’ve disrupted his focus. I think he’s right to question Hawk-Eye on clay, where visual evidence is literally underfoot, but taking matters into his own hands crossed a line for the umpire this time. Maybe there should be a compromise at clay events—use Hawk-Eye but allow umpires to check marks in disputed cases. What is your opinion on these live calling systems? Let us know in the comments.
There’s no way Hawk Eye’s error margin of 3mm is accurate on all shots – even on hard courts
At Indian Wells and other tournaments, I have watched balls bounce far enough out to see “daylight” of court between the bounce and the line and hawk eye made no call. These were not all even particularly fast shots that are hard to see.
It’s been obvious on television replays, too, on the rare occasion that they actually show you the slow-motion replay of the ball bounce (instead of just a computer “drawing” of a ball that is in or out with no proof that is where your ball landed).
I have also seen chair umpires overrule Hawk Eye in ATP events. Nacho Forcadell did it on a serve when the Hawk Eye call was obviously wrong.
I think they should get rid of Hawk Eye and just use the “Real Bounce” system that some smaller tournaments use where the call is proven with super-zoomed in slow motion video footage of the bounce. It takes a couple more seconds but seems more accurate and proves its calls, which is important.