It’s the moment you’ve all been waiting for. Yes, this is the big, exciting weekend that’ll see the introduction of semi-automated offside technology in the Premier League.
If that sounds like gibberish to you, here’s Ben Fisher’s handy explainer.
What is semi-automated offside?
Semi-automated offside technology (SAOT) is a tool that automates key elements of the offside decision-making process for the video assistant referee (VAR). It will first be used for the first time in the Premier League when Manchester City host Crystal Palace on Saturday lunchtime. The league hopes SAOT will address a key frustration: delays. Once a SAOT-generated outcome has been reviewed and approved by the VAR, the decision will be relayed to those inside the stadium on screens and shared on social media, via the league’s PLMatchCentre X account.
How will it help?
It should speed up decisions, though before last weekend the average VAR delay per game was down from 64 seconds in 2023-24 to 39 in 2024-25. The league believes SAOT will deliver efficiency and consistency. For example, it is thought the VAR check for Moisés Caicedo’s disallowed goal for Chelsea against Tottenham this month, when Levi Colwill was deemed offside, which took more than three minutes, would have taken less than half the time with SAOT. It will not, though, eradicate delays.
How does it work?
The system uses up to 30 cameras mounted around stadiums – with most capturing footage at 100 frames per second, twice the frame of typical broadcast cameras. The technology tracks the movement of the ball and up to 10,000 data points per player to produce a ‘virtual world’ in which potential offsides are detected. Those are automatically flagged to the VAR, reducing the possibility of missing an offside. In the Premier League this season, offside calls have been adjudged to be 100% correct.
Will SAOT mean more ‘toenail’ offsides?
No. The league will continue to implement the “tolerance level” sometimes referred to as “thicker lines”, of about 5cm, which gives the benefit of the doubt to the attacking team and prevents marginal offsides. The league adopted the approach at the start of the 2021-22 season and the sense is it has been well-received by clubs.
Why the wait?
The league wanted to be confident there would be a near-seamless incorporation. It has been testing the technology from November and although it was hoped SAOT would be in use last autumn, the league further delayed its introduction after an eight-minute VAR delay when it was trialled in the FA Cup fifth round in March. The technology did not work during Bournemouth’s win over Wolves, before Milos Kerkez’s first-half goal was disallowed, because the ball was obscured by numerous players. In those cases, officials will revert to the current VAR technology.
