VAR vs. Semi-Automated Offside Technology: What Changed
VAR is the review process; semi-automated offside technology is the tool that makes one part of it faster. Here's what actually changed since the Premier League and FIFA adopted camera-based offside tracking.
Fabian Schär thought he'd scored. The Newcastle defender drilled a late finish against Brighton & Hove Albion in an FA Cup tie on March 2, 2025, and for a few seconds it looked like a winner. Then semi-automated offside technology stepped in, drew the line, and chalked it off. Brighton went on to win in extra time. It was the first goal ever disallowed by the system in English football — and a preview of the tool now running quietly behind every close call at the 2026 World Cup.
SAOT and VAR get used almost interchangeably by fans, but they're not the same thing. VAR is the review system — the process of a video assistant referee checking a decision. Semi-automated offside technology is a specific tool that VAR uses for one type of call. Understanding the difference explains why some offside reviews now take ten seconds and others still take four minutes.
The old way: a human drawing lines by hand
Before SAOT, a close offside call meant a replay operator manually finding the exact "kick-point" — the frame where the ball left the passer's foot — then drawing crosshair lines across the pitch by hand, using whichever broadcast camera angle gave the clearest view. Only once those lines were placed could the system generate an onside or offside verdict.
The process was slow and, more damagingly, looked arbitrary to fans watching lines that sometimes sat almost on top of each other. It also wasn't foolproof: in February 2023, VAR failed to flag an offside Brentford player in the buildup to a goal against Arsenal, and on the same day, mislabeled lines led to a Brighton goal being wrongly disallowed. In October 2023, Liverpool had a legitimate goal ruled out at Tottenham after VAR missed a correction entirely.
What semi-automated technology actually changes
SAOT replaces the manual line-drawing with optical tracking. FIFA and UEFA's version uses 10 to 12 cameras mounted in the stadium roof, tracking roughly 29 data points per player at 50 frames per second — the same frame rate as a standard broadcast camera. The Premier League's version, built with Genius Sports, is more elaborate: up to 30 iPhones (model 14 or newer) fixed under the stadium roof, capturing 100 frames per second and tracking up to 10,000 surface "mesh" points across each player's limbs and extremities.
Both versions do the same basic job faster: the cameras track the ball and every player in real time, the software flags a potential offside, and it automatically proposes both the kick-point and the offside line — work a human used to do by hand. A 3D animation is then generated for broadcast and the stadium screen, replacing the old flat, two-dimensional crosshair graphic.
Why it's only "semi" automated
The video assistant referee never gets removed from the loop. The system flags a decision, but a human still has to confirm that the software identified the correct kick-point, the correct players, and the correct body part — and still has to make the judgment calls SAOT can't touch. Was an attacker "interfering with play" without touching the ball? Did a defender make a deliberate play that resets the phase? Those subjective calls still go to the referee, sometimes with a pitchside monitor review.
There's also a hardware difference most fans don't know about. FIFA's World Cup ball carries a suspended sensor near its core — a patented design licensed to Adidas — that flags the exact moment of a kick without any camera work. No European domestic league uses that ball, because none of them contracts with Adidas, so the Premier League, Serie A, LaLiga and the Champions League all rely purely on optical tracking to estimate the kick-point instead of sensing it directly. It's a meaningful gap in precision that the Premier League's chief football officer, Tony Scholes, has argued its camera density is built to close.
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Does it actually change how many goals get disallowed?
No — and that's by design. The Premier League has said SAOT doesn't change the accuracy of decisions, only the speed and consistency of reaching them. The league has also kept its "tolerance level," a roughly 5-centimeter benefit of the doubt introduced in 2021-22 to cut down on so-called "toenail" offsides, a buffer other SAOT leagues don't use. What does change is the clock: the Premier League estimated close offside reviews got about 30 seconds faster on average once SAOT arrived, with some of the worst cases — like an April 2025 Chelsea-Tottenham review that ran past four minutes under the old system — cut by roughly two minutes in trials.
It isn't a cure-all. Games with multiple overlapping incidents, or camera angles blocked by clustered players, still force officials back to manual crosshairs. An FA Cup tie between Bournemouth and Wolves in March 2025 needed an eight-minute review spanning two possible handballs and an offside — SAOT couldn't shortcut that one at all.
Where the technology goes next
Serie A was first among Europe's major domestic leagues to adopt SAOT, in January 2023, after a stoppage-time Juventus goal was wrongly disallowed the previous season. LaLiga followed for 2024-25, and the Premier League brought its camera-heavy version into live matches on April 12, 2025 — first spotted flagging Crystal Palace's Eberechi Eze offside against Manchester City, then disallowing Kieran Tierney's opener for Arsenal against Brentford on the same afternoon. At this summer's World Cup, the FIFA version with its chipped ball is running in every stadium, the fullest test yet of whether sensor data and optical tracking together can finally make offside calls fast and trusted.
