Tech football

What Is Semi-Automated Offside Technology & How Does It Work?

VAR, eh? It was supposed to be the end game for inaccurate officiating decisions in football, with video technology introduced to eliminate human error and bring us crashing into an AI powered future. Unfortunately, like the plot of some post-apocalyptic Hollywood thriller, the technology has not worked in fact – in fact, it’s driven a wedge into the beautiful game like never before. Questions of inaccuracy, incompetence amongst those deploying the tech and the interminable wait for a decision to be made have condemned VAR to football’s ‘we tried but it was rubbish’ pile.

But help could be at hand, at least in boosting the accuracy of offside decisions, anyway. The Premier League is planning to introduce ‘semi-automated offside technology’ during the 2024/25 season, with the hope that both the quality of officiating – and the speed with which decisions are made – will increase exponentially.

“The technology will provide quicker and consistent placement of the virtual offside line, based on optical player tracking, and will produce high-quality broadcast graphics to ensure an enhanced in-stadium and broadcast experience for supporters,” so said the Premier League’s press release. But will the technology actually deliver on its stated aims this time?

What Are Semi-Automated Offsides?

Perhaps sensing that VAR couldn’t cut the mustard, FIFA deployed a number of technicians and engineers to come up with a better and more accurate way to officiate offside calls – negating the need for the weird lines drawn on-screen by video officials. After a semi-automated system was devised, FIFA rolled it out during a number of minor international tournaments – satisfied with the results, they announced full implementation at the World Cup in 2022.

The technology was considered to be a success, so by April 2024 there was interest in introducing semi-automated offsides in the Premier League too. After a meeting of EPL shareholders, all clubs voted unanimously in favour of the tech. It’s thought that it will be rolled out a few months into the 2024/25 season.

Semi-automated offsides will be decided by a series of cameras in conjunction with tracking software, which is said to be accurate to within a few millimetres. This process is all automated, with the only intervention of a VAR official coming as they check whether or not the ‘offside’ player is interfering with play or not.

By removing the need for human intervention, offside calls are sped up and a 3D visual is shown on the big screen (at stadia that have them). According to FIFA’s trials, semi-automated offsides take around 20 seconds from detection to a decision being taken – a significant decrease on the VAR-led time, which is approximately 70 seconds.

How Does Semi-Automated Offside Technology Work?


The new system, which is abbreviated to SAOT (Semi-Automated Offside Technology), is the pinnacle of sporting innovation. It utilises 12 dynamic optical tracking cameras, which can track as many as 29 different parts of the human anatomy – which, exactly, has not been revealed.

So every player’s movement and position on the pitch is monitored, with information relayed to the data centre 50 times per second. A new match ball, complete with an inertial sensor, will also transmit data at 500 hertz for the minimum of lag and delays.

Using AI, those managing the SAOT tech are able to see in real time when an offside decision is made – video officials check their screen, confirm that the offside player is interfering with play, and then buzz the on-field officials to let them know of the verdict.

One of the key elements of the new system is that a digitally rendered 3D graphic is created – the tracking software creating the visual from its data points and the tracked positioning of each players’ limbs.

This can then be displayed on big screens and scoreboards, allowing fans to see why the offside decision has been made – a big improvement on the current VAR system, which leaves in-stadium supporters (and even those watching on TV) completely in the dark as to why a call has been taken.

Is Semi-Automated Offside Tech Accurate?

Of course, all of this counts for absolutely nothing if the technology itself is inaccurate – rendering it useless, and affecting the integrity of the games it is used for. The good news, so far, is that SAOT has delivered the goods, getting the absolute vast majority of its calls correct – with a 100% approval rate at the World Cup.

Indeed, the tech played a key part in ensuring that games weren’t decided by dodgy goals. Croatia had a goal ruled out against Belgium after Dejan Lovren had crept into an offside position – a margin so tight to the naked eye that a ‘non tech’ based decision simply wouldn’t have been able to have been made.

That had come after the first official use of SAOT at the World Cup in the opening game – Ecuador’s Enner Valencia adjudged to have been offside when scoring against the hosts Qatar. The decision proved to be correct, although there was an embarrassing two-minute wait for the official 3D graphics to be ready for display.

FIFA have thus far been delighted with the results of their SAOT system. “Based on the test results gathered during the three-year testing phase, semi-automated offside technology is currently the most accurate offside support system available to video match officials,” they have reported.

In addition, the system provides consistency in the placement of offside lines, especially in situations where the shoulder or top part of the arm determines the offside line.

FIFA’s head of officiating, Pierluigi Collina – not a man to be trifled with during his long and distinguished refereeing career, is also adamant that the technology works. “The objective is to have a very accurate technology, something similar to goal line technology, which offers a very, very high accuracy,” he said.

It went down from the initial three centimetres to very few millimetres today. And the goal line technology is praised by everybody for its accuracy.