No More Line Judges on the Baseline: When Tennis Hands the Truth to Machines

No More Line Judges on the Baseline: When Tennis Hands the Truth to Machines On January 3, 2026, at the Brisbane International, a Holger Rune serve was called out. No arm went up. No human voice shouted out. There was only a synthesised voice from the speaker system, steady as a metronome. The crowd fell silent for two seconds. Not out of outrage. But because something had just vanished from the court, and no one managed to name it. I was sitting in front of a screen in Sydney, notebook in hand, and wrote down one line: How many times now have I not seen a line judge? That was the first question that came to me. But then I realised the real question was not the presence or absence of line judges. The real question was: when the human eye leaves the baseline, what are we trading for, and what are we losing? In my trade, people call this moment the handover point. A duty that once belonged to people is being transferred to machines, and tennis is the last of the major sports to hand it over so quietly. Roland Garros held out the longest, but by 2026 it too had bowed to the trend. This is no longer an experiment. This is a transfer of power. And like every transfer of power, it has two faces. The human eye sees only the ball touching the ground; the referee's eye sees the intent behind the fault. Machines see only coordinates, not intent. And that is exactly where the story gets complicated. Hawk-Eye uses roughly ten cameras, and its margin of error is around 3.6 millimetres, far smaller than a tennis ball. Human line judges, in fast conditions, can misjudge a ball near the line by several centimetres. So machines are more accurate, and not by a little. But accuracy is not the whole story. In five years working as a rules analyst, I have learned something: rules do not exist to punish, but to keep the match from becoming a game of chance. The question is not whether the machine is more accurate. The question is whether it makes the match feel fairer to the players and the fans. VAR did not kill football, it exposed a truth we had long refused to admit. But a truth exposed at the right moment and a truth exposed too late create two very different experiences. ELC solves only one kind of call: the ball out. It does not solve foot faults, hindrance calls, whether a ball touched racket or hand, reckless intent, or the right to a medical timeout. In other words, machines replace humans only in the easiest part of the job: measuring distance. The hardest part remains with people. Line judges were never just people calling balls out. They were part of the ritual. When they disappear, a ritual disappears with them. And there is a cost that is economic as well: tournaments save money on staff, and hundreds of professional line judges lose a livelihood. With the fans, a tennis match is not just a precise string of scores. It is a story with emotion. When a machine calls the ball out, fans lose the right to argue, the right to judge for themselves. The best referee is the one who knows where he went wrong before anyone points it out. Machines do not feel shame when they err, and cannot offer a player in crisis the kind of look only a human can give. If I had to predict, in ten years ELC will be the global standard, even at junior and grassroots level. At the same time, the role of the chair umpire will grow, not shrink. And I always write long analyses, even knowing most readers only read the headline. I do not believe in the final verdict; I believe in the chain of reasoning that leads to it. After the synthesised voice called Rune's serve out, the match continued within seconds. No one was wrongly penalised. Everything worked as designed. But in my notebook, I wrote one more line: what I am missing is not accuracy, but the sound of a call in a human voice. I do not oppose technology. I only want to record that every advance has a price. And that price lies in the things data cannot measure, like the moment a stadium falls silent because there is no longer anyone to look at. If asked whether I would go back to the age of line judges, I would say no, because fairness now must be guaranteed by both the accuracy of the machine and the understanding of the human. Tennis has passed through one of the great turns in its history, and the human fence on the baseline has receded into the past.