How Does Wimbledon's Electronic Line Calling Work?

The 139th Championships (29 June – 12 July 2026) introduce two officiating upgrades. The biggest is video review, available for the first time in Wimbledon history: players can ask the chair umpire to re-watch specific judgement calls on six courts — Centre Court and No. 1 Court for all matches, plus No. 2 Court, No. 3 Court, Court 12 and Court 18 for singles.

The second change is smaller but answers a 2025 complaint: scoreboards on every court, including qualifying, now show visual 'out' and 'fault' indicators for the electronic line calling. In 2025, players — including Emma Raducanu and Aryna Sabalenka — said the automated voice calls were sometimes hard to hear over crowd noise.

The All England Club announced both changes on 21 March 2026, framing them as a direct response to feedback from the first year of live electronic line calling. Wimbledon is the third Grand Slam to adopt video review, after its debut at the 2023 US Open and subsequent adoption by the Australian Open.

Together the two systems split officiating cleanly: the machine calls the lines, and the human umpire keeps the judgement calls — a division that is reshaping how technology assists judges across sports.

Wimbledon's live electronic line calling (ELC) is built on Hawk-Eye, the same ball-tracking system that once powered the challenge review. 18 cameras around each court follow the ball in real time, and an automated voice announces 'out!' or 'fault!' within a fraction of a second of the bounce.

The call is live and final. There are no line judges to overrule and no challenge system — the theatrical pause while the crowd claps a Hawk-Eye animation onto the screen disappeared with the arrival of live calling in 2025. Players can still ask for a replay to be shown, but the replay cannot change the call.

The human presence has shrunk dramatically. Wimbledon employed around 300 line judges before the switch; since 2025 roughly 80 remain as 'match assistants', on standby in case the technology fails. Line judges had stood on Wimbledon's courts for 148 years, since the first Championships in 1877.

Wimbledon was a late adopter by tour standards: the ATP Tour has used live ELC at all of its events since the start of 2025, and the Australian Open and US Open converted earlier. Grass also removes the fallback that clay offers — there is no readable ball mark, so once the line judges left, the camera system became the only witness to where the ball landed.

Video review does not cover line calls — those belong to the ELC and are final. It covers judgement calls made by the chair umpire, where the umpire's eyes were previously the only evidence. Per the All England Club's announcement, the reviewable calls include 'not-up' (the ball bounced twice before the player struck it), 'foul shot' (an illegal stroke, such as a double hit) and 'touch' (the ball touched a player, or a player touched the net).

A review can be requested in three situations: on a point-ending call, when a player immediately stops play, or immediately after the completion of a point in the case of hindrance. Players have unlimited review requests — there is no penalty for asking and losing, unlike the old challenge system for line calls, which allowed three incorrect challenges per set.

There is no separate video official. The chair umpire watches the footage back on a screen at the chair and makes the final decision — the same official who made the original call also rules on the review.

The technology's debut year produced two high-profile failures. In the 2025 fourth round between Anastasia Pavlyuchenkova and Sonay Kartal, an operator deactivated the ball tracking in error on one side of the court for a full game. Three calls went unmade; when a Kartal shot landed clearly long without an 'out' call, umpire Nico Helwerth stopped play and ordered the point replayed. Pavlyuchenkova, denied a 5-4 lead, told him: "They stole the game from me." Wimbledon apologised to both players and removed the operators' ability to switch the tracking off — the failure mode cannot recur.

Days later, in the quarter-final between Taylor Fritz and Karen Khachanov, the system called 'fault' on a Fritz forehand that had landed inside the baseline. The cause: the tracking had not reset after a ball was retrieved during Fritz's first serve.

Player trust split. Jack Draper said: "I don't think it's 100 per cent accurate, in all honesty"; Emma Raducanu said she did not trust it after what she saw as a missed call; Belinda Bencic reported the same view was common in the locker room. On the other side, Taylor Fritz called it "a better system" than human line judges, and Novak Djokovic said the technology is "probably more accurate" than a lines person — while conceding that system failures at awkward moments are the price.

The pattern matches what football learned with VAR: precision technology does not end arguments — it moves them, from 'was the ball out?' to 'can we trust the machine?'

Tennis has quietly adopted the same officiating split football uses: factual, measurable calls go to the machine; judgement calls stay with the human, now supported by replay.

Whether a ball landed in or out is a measurable fact — a camera array answers it better than any human eye, so the call is automated and unchallengeable. Whether a ball bounced twice, whether a player's frame double-hit the ball, whether a hand brushed the net — these are interpretation calls that depend on what the umpire perceived, so they stay with the chair and gain a video safety net.

One design choice stands out: at Wimbledon, the chair umpire reviews their own call. Football separates the roles — a VAR official watches remotely and recommends a review. Tennis trusts a single official to overrule themselves on replay evidence, which keeps authority in one place but asks the umpire to be their own critic.

This measure-versus-judge split is the core of modern officiating design, and it is the principle behind how AI and technology are entering judged sports. Scoring platforms like JudgeMate are built around the same division: the system records, times and computes what is measurable, so human judges can spend their attention on what genuinely requires judgement.

The four majors have landed in three different places. The Australian Open and US Open run live electronic line calling with video review — the US Open pioneered video review in 2023. Wimbledon joined them fully in 2026, adding video review to the ELC it adopted in 2025.

Roland-Garros is the outlier. The French federation confirmed that human line judges stay for 2026, with vice-president Lionel Ollinger saying the tournament "will continue to show off the excellence of French umpiring". Clay makes the choice defensible: the ball leaves a readable mark, and the chair umpire climbs down to inspect it on request — a physical review system no other surface offers.

Here is how a video review runs on Centre Court in 2026, at 5-5 in a deciding set.

Step 1 — The call. Player A plays a drop shot. Player B sprints in and flicks the ball over the net. The chair umpire calls 'not up' — ruling the ball bounced twice before B's racquet arrived. The call ends the point in A's favour.

Step 2 — The request. B walks to the chair and requests a video review. It is a point-ending call, so it qualifies. B has already used two reviews earlier in the match — it does not matter, because requests are unlimited.

Step 3 — The review. There is no video umpire to consult. The chair umpire re-watches the pickup on the review screen, frame by frame, while the stadium sees the same replay.

Step 4 — The decision. The footage shows a sliver of grass between the second bounce and the strike — the ball was up. The umpire overturns their own call and announces the correction.

Step 5 — The outcome. Play is resolved per the rules of tennis for a corrected call, and the score is updated. The review costs B nothing: no counter ticks down, and the next point starts with the same rights.

Total elapsed time: under a minute — closer to a cricket DRS check than to a multi-angle VAR deliberation.