Umpire Nico Helwerth opted to replay a point when a ‘human error’ led to the line-calling technology being deactivated
Wimbledon 2025
Dates: 30 June-13 July Venue: All England Club
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Wimbledon officials have implemented changes to its electronic line calling system to mitigate the possibility of “human error,” following an accidental deactivation incident on Sunday.
An “operator error” resulted in the ball-tracking technology being disabled for a portion of the fourth-round match between Sonay Kartal of Great Britain and Russia’s Anastasia Pavlyuchenkova on Centre Court.
“Following a thorough review, we have eliminated the capacity for Hawk-Eye operators to manually deactivate the ball tracking system,” the All England Lawn Tennis Club (AELTC) stated to BBC Sport.
“While the root cause was identified as human error, the implemented system changes will prevent a recurrence of this issue.”
During a game point at 4-4, Kartal’s backhand shot landed long, but the line-call system failed to detect it, triggering two automated “stop” calls instead.
Umpire Nico Helwerth’s decision to replay the point, which Kartal subsequently won, drew criticism from Pavlyuchenkova and some commentators who argued he should have overruled the call and declared the ball out.
Television replays clearly showed the ball landing beyond the line, prompting Pavlyuchenkova to advocate for a video review system akin to those used in football, enabling umpires to make informed decisions.
The AELTC defended Helwerth’s actions, stating he had “adhered to the established protocol,” while adding that the implementation of video reviews would be “among the issues to be considered” at the conclusion of the Championships.
Club chief executive Sally Bolton confirmed earlier in the week that Helwerth was “having a rest day.”
“We operate a regular rotation of umpires. Similar to the players, the umpires require rest days throughout the tournament,” Bolton told BBC Sport.
“He is taking a rest day today and is in good spirits.
“It is important to emphasize that the umpire followed the established protocols. He acted appropriately on court and adhered to the guidelines.”
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Electronic line calling is widely implemented in numerous top-tier tournaments, with both the US Open and Australian Open incorporating a video review system.
Previously, when line judges were present at Wimbledon, players could challenge calls using electronic review technology. The current system does not permit challenges, and video replays are not utilized.
While replays of points can be shown on the big screens, they essentially reflect the technology’s assessment and only indicate “close calls.”
Given the widespread availability of televised replays, viewers are left to question the umpire’s inability to leverage such footage when uncertainty arises regarding a call.
Pavlyuchenkova suggested that tennis should embrace video checks similar to those in football “so that we can review the point.”
“I think it is a necessity at such a major event, considering this is not an isolated incident,” she told BBC Sport on Sunday.
The AELTC stated: “We do not currently incorporate a video review system within our officiating protocols.”
“As part of our annual review process, we will comprehensively assess all aspects of The Championships’ operation, including this matter.”
The electronic system was introduced at this year’s Championships, replacing line judges, who had been a fixture on court for 147 years.
The technology represents an “enhanced” version of the previous Hawk-Eye system used for player challenges to line judge calls.
A dedicated line-calling hub located within Wimbledon’s grounds houses 50 operators monitoring ball-tracking footage from 12 cameras per court on 144 screens.
The AELTC reaffirmed its “full confidence in the accuracy of the ball-tracking technology.”
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Kartal wins controversial game after electronic line-calling system fails