Wimbledon 2026 drops line judges: the limits of a system that cannot admit error

2 a.m. in Hai Phong. The match on screen had ended four hours earlier, yet I was still sitting in front of an unfinished analysis file. The file had a title, nine sections and very tidy little tables. Almost every cell was empty: no player name, no tournament name, no figure for first-serve percentage or return points won.

I found that offside at 2 a.m., after everyone had gone home. This time there was no offside at all. Only a gap — and in my trade, a gap is itself a form of evidence. It forces the analyst to choose one of two things: invent a plausible-sounding verdict, or keep the emptiness and live with how useless that feels. I chose the second. The only note I left in the file read: not enough data to conclude.

That sounds like a private story, until tennis did exactly the same thing on a global scale.

Wimbledon 2026 was the first edition in 147 years with no line judges on court. Every in-or-out call belonged to Electronic Line Calling. The ATP announced that from the 2026 season, ELC Live would be used at every event on the ATP Tour. The US Open brought Hawk-Eye Live in from 2026, initially on most courts, partly to reduce the number of people inside the grounds during the pandemic.

The story is usually told starting from a human failure. The 2026 US Open quarter-final between Serena Williams and Jennifer Capriati is the classic case: chair umpire Mariana Alves made a series of errors in decisive games, and replays showed the ball clearly landing inside the lines. Two years later, the 2026 US Open became the first Grand Slam to let players request a Hawk-Eye review. From there to Wimbledon 2026 is nearly two decades of authority migrating from human eyes to a computational model.

What that story rarely mentions is the technical nature of the replacement. Hawk-Eye operates more like a computational model than a camera. Independent studies typically place its margin of error at around 3.6 mm, while the ball touches the court for roughly four milliseconds. No human can read an interval that short. A machine has to infer it.

Based on my experience tracking matches, one technical detail decides the whole story: the system does not see the bounce. It reconstructs the ball's three-dimensional trajectory from data supplied by multiple cameras positioned around the court, then extrapolates the final contact point. When the trajectory is obstructed — a player standing in front of a lens, a ball passing tight to the net post, a crowd raising its arms — the system is forced to interpolate. That interpolation never appears on the big screen. The stands only see a clean animated arc and the word IN or OUT.

This is where I see the parallel with my own empty file. In both cases, the pressure to reach a conclusion is identical; the input data is not. The difference is that a written analyst is compelled to disclose the shortfall, while a commercial system is not.

In football, VAR has a buffer layer that tennis lacks. VAR officials work with a clear-and-obvious threshold, a historical scale of sanctions, and the right to uphold the original decision when evidence is insufficient. At the 2026 AFC Cup, I handled an offside that was 0.3 metres out, and that signal only carried meaning because a human being stood behind the number. Tennis has no such buffer. In or out is a binary ruling, and an ELC decision is final. There is no uphold-the-on-field-call option for the system.

A system that does not publish its own extrapolation rate is not an accurate system — it is an untested one. Three figures should be released after every match: how many times the system had to interpolate because of obstruction, the estimated error of each interpolation, and how many times an operator intervened manually. Without those three figures, spectators are forced to trust a brand's reputation instead of trusting data.

In tennis the in/out ruling is binary, but the data that produces it is not. The distance between those two things is where the biggest arguments are born, and where the media almost never looks.

A counter-intuitive view: removing line judges raises average accuracy but lowers the capacity for scrutiny. A line judge has a name, an accreditation number, and can be questioned, assessed and disciplined. That means a human error can be corrected at system level. An electronic system has no name to question.

There are offsides nobody sees, but the cameras never blink — that line has held true for me for years. Not blinking, however, does not mean always seeing. A model can be looking somewhere else, very confidently, and nobody inside the stadium has the authority to say it looked wrongly. In that moment, spectators fill the gap with emotion, and the analyst has to stay silent. Staying silent at the right moment is a form of professional courage, even though it earns no views.

The biggest mistake is not holding the whistle; it is refusing to own your own whistle. When rulings are handed entirely to a system that never speaks, responsibility becomes ownerless. Nobody has to own any whistle, even when that whistle comes from an obstructed extrapolation in a corner of the court that nobody noticed.

What I want to see next season is not a new technology but a new document: a system log published after every match. If the ATP and the Grand Slam organisers choose that route, trust in electronic officiating will be built on verifiable data rather than on pure faith. The question is no longer whether the machine is wrong. The question is when we will be allowed to read its error log.