7 Semi-Automated Offside Mistakes Fans Make in 2026

7 Semi-Automated Offside Mistakes Fans Make in 2026

Semi-automated offside technology (SAOT) is a FIFA-tested officiating system that uses roughly a dozen optical tracking cameras, a sensor inside the match ball and computer-generated offside lines to tell video referees, within seconds, where every player stood when the ball was played. First used at the 2022 FIFA World Cup in Qatar, it now runs across UEFA competitions, the AFC Asian Cup, the FA Cup and the Premier League, and it has become the reference point for offside debates around the 2026 World Cup. FIFA's figures put its tracking at 29 body points per player, sampled 50 times a second, with a ball sensor reporting at 500 Hz. The system is called semi-automated because a human official still confirms the kick point and the final decision. The practical takeaway: judge the call by the kick-point frame, not by how clean the drawn line looks.

On 22 November 2022, at Lusail Stadium, Argentina lost 2-1 to Saudi Arabia in their World Cup opener after having goals ruled out for offside three times in the first half. I was awake at 3 a.m. with a notebook, pausing every replay, and listen up, this is the part that matters: none of those calls was settled by a linesman's eyeball. Each was settled by a skeleton of tracked points and a line drawn on a 3D model, and the margins were small enough that most fans simply refused to believe them. Four years on, the same technology sits behind offside reviews from the FA Cup to UEFA competitions, and the argument has not cooled. At Fan Strategy we follow the 2026 World Cup daily, and the same seven misreadings keep surfacing in comment sections, group chats and in-play betting slips. None of them is foolish. Each is the natural result of a name that promises more automation than the system actually delivers. Below are the five steps I use to read a call properly, with each mistake marked where it usually happens.

The seven mistakes, in order of appearance:

• Mistake 1: treating SAOT as a robot referee that overrules people.
• Mistake 2: assuming every league runs the same hardware, including a ball sensor.
• Mistake 3: believing the freeze frame is chosen arbitrarily.
• Mistake 4: ignoring the sampling gap between the ball sensor and the player data.
• Mistake 5: blaming the machine for judgement calls it never makes.
• Mistake 6: reading an offside position as an offside offence.
• Mistake 7: expecting the system never to fail, and having no plan when it does.

Ready to see how the numbers behind these calls fit together? Here is a closer look at our World Cup coverage.

Learn More

Step 1: What Does the System Actually Track?

It tracks two things at once: every player's body and the ball. Twelve roof-mounted cameras follow 29 body points per player 50 times a second, while a sensor inside the ball logs contact at 500 Hz. Together they produce a live 3D skeleton model of all 22 players, which is what the offside line is drawn from.

Mistake 1 is the belief that this is a robot referee. According to Wikipedia's entry on semi-automated offside technology, it is an officiating support system that assists video assistant referee teams by supplying tracking data and automated alerts, while the final decision stays with match officials. The supplier Genius Sports sells its version of the product with the promise "Fast offside calls, every time", and notice that the promise is about speed, not about removing people. Mistake 2 is assuming every competition runs identical hardware. The same Wikipedia entry says the ball sensor is used only "in some implementations". Where a league has cameras but no sensor ball, an operator has to pick the kick point from video, and the 500 Hz precision I quoted above simply does not exist. Before you argue about a call in any competition, find out which setup it uses. A Premier League match, an FA Cup tie and a continental qualifier can all say "SAOT" on the graphics while running meaningfully different pipelines underneath. [Internal Link: how video assistant referees work in World Cup matches]

Step 2: How Does It Find the Exact Kick Moment?

The ball sensor detects the instant of contact, and the system matches that timestamp to the player-tracking frame closest to it. Because players are sampled at 50 Hz, the nearest frame can be up to 10 milliseconds away, roughly 8 centimetres for a sprinter at 8 metres per second.

That last figure is my own arithmetic, and it is the detail almost no explainer mentions. Players are sampled every 20 milliseconds, so the worst-case gap between the true kick and the nearest frame is half of that, 10 ms. A winger at full tilt covers about 8 cm in that window, before any interpolation the software applies to smooth it out. This is mistake 3 and mistake 4 in one breath: fans assume the freeze frame was picked to suit a narrative, and then forget that the frame itself carries a physical tolerance. The honest reading is that a call decided by 3 cm sits inside the uncertainty of the method, while a call decided by 25 cm does not. I am not claiming the system is wrong in the first case, only that the drawn precision looks tighter than the measurement behind it. For a data person, that gap between how precise a graphic looks and how precise the input is should be the first thing you check. [Internal Link: player tracking data and what it reveals about tactics]

Here is the practical order of events once a possible offence is flagged:

1. The ball sensor reports a contact spike, or an operator marks the kick point on video.
2. The system selects the tracking frame nearest that moment.
3. The skeleton model for both teams is frozen at that frame.
4. The offside line is generated from the relevant body points.
5. The video operator confirms, and the result goes to the video assistant referee.

Seeing the pipeline as a chain makes it easier to ask the right question when a call looks strange: which link produced the surprise?

Curious how this feeds into our match-by-match breakdowns? Take a look before the next fixture.

Learn More

Step 3: Who Makes the Call?

Match officials do. The system flags a possible offside and proposes a kick point; a video operator confirms it, the video assistant referee reviews the result, and the on-field referee still announces the decision. The technology supplies evidence and speed, not authority, which is why Wikipedia describes it as an officiating support system.

Mistake 5 is blaming the machine for judgement calls it never makes. SAOT answers one narrow question: where were the players at the moment of the kick? It says nothing about whether an attacker in an offside position interfered with play, whether a defender's touch was a deliberate play or a deflection, or whether the ball was last touched by a teammate at all. Those are human decisions under Law 11, and they are where most of the genuinely contestable moments live. What the technology did change is the clock. FIFA has said that automated lines cut the average offside review at the 2022 World Cup from about 70 seconds to about 25 seconds, and that is the real benefit: a shorter wait between the ball hitting the net and the verdict. In practice, when a review drags on now, the delay is usually a human question, such as the deflection or the phase of play, rather than a line-drawing problem. [Internal Link: offside law changes and referee decision timelines]

Step 4: How Should You Read the Lines on Screen?

Read the line as a model, not a photograph. The 3D animation shows where the tracked body points were at the kick frame, and the attacker is offside only if any part of the head, body or feet is nearer the goal line than both the ball and the second-last opponent. Hands and arms do not count.

Mistake 6 is reading an offside position as an offside offence. The IFAB Laws of the Game define the position as one where "any part of the head, body or feet is nearer to the opponents' goal line than both the ball and the second-last opponent", and being there is not an offence in itself. The player must also become involved in active play. So when the graphic shows a pale shaded band and one shoulder across it, the question is not only whether the shoulder crossed, but whether that player then touched the ball, blocked a defender's line of sight or challenged for it. The second trap is the camera angle. The animated view is generated from tracked data, so it can be rotated to look along the offside line, while a broadcast replay is shot from a fixed lens and can distort depth. If the 3D view and the replay seem to disagree, trust the 3D model for position and the replay for contact. Last, remember that there is no tolerance band: under the Laws, a margin of one centimetre is still offside.

Want the same discipline applied to tactical previews? Keep going with our tournament notes.

Learn More

Step 5: Verification

Verification means checking the call yourself in five moves before you trust or reject it. Confirm which technology the competition uses, find the kick-point frame, read the line against the correct body part, ask whether involvement in play was judged, and note the margin. Doing this takes about two minutes and ends most arguments quickly.

Here is the checklist I run from the sofa:

1. Setup check. Does the competition use a ball sensor, or an operator-chosen kick point? The answer sets how much precision to expect.
2. Frame check. Step the replay to the moment of contact. If the foot is still approaching or already past the ball, the chosen frame is worth questioning.
3. Body-part check. Identify which part of the head, body or feet is ahead of the line. Arms and hands are excluded, and a goalkeeper-style reach does not make anyone offside.
4. Involvement check. Ask whether the player in the offside position touched the ball or clearly affected a defender.
5. Margin check. Compare the gap to the roughly 8 cm sampling tolerance from Step 2. A gap under that is a close call, not a scandal.

One more point that matters for anyone who bets on matches: a disallowed goal can change a market after the fact, and the way operators handle goals under review varies between rulebooks. Read the specific settlement terms for your operator before staking anything, and only ever stake what you can afford to lose. My own habit is to treat an in-play market as unreliable while a VAR check is on screen. [Internal Link: how in-play betting markets settle goals under review]

Troubleshooting Common Failures

Mistake 7 is expecting the technology never to fail and having no plan when it does. The system can lose clean tracking in crowded penalty areas, the ball sensor can drop out, or the review can fall back to manual lines drawn on broadcast footage. When that happens, the fallback is slower and less precise, so expect longer waits and thicker lines.

Four failure patterns recur, and each has a sensible response:

• Players bunched in the box. Occlusion makes some body points harder to resolve, so the operator may need extra time to confirm. Expect a longer check, not a different rulebook.
• Ball sensor dropout. The kick point reverts to operator judgement from video, which lowers precision. Treat very tight margins with more caution.
• Replay and 3D view disagree. Different lenses and a generated model will never match perfectly. Use the 3D model for position and the replay for contact.
• A league without SAOT. Manual VAR lines apply, and the line thickness alone can exceed several centimetres on the pitch. Do not hold that league to the tracking standard of a World Cup.

The underlying lesson is that semi-automation is a promise about workflow, not about perfection. It speeds up the check, narrows the argument and leaves the human at the end of the chain. If you keep the seven mistakes in mind, you will read most offside decisions more calmly than the commentary does, and you will know exactly which link to blame when something still feels wrong. That is the kind of detail we try to bring to every match preview at Fan Strategy.

Want a steady stream of match insight through the tournament? Join us for the rest of the World Cup.

Learn More

Frequently Asked Questions

Q: What is semi-automated offside technology?

A: It is an officiating support system that uses tracking cameras, computer-generated offside lines and, in some versions, a ball sensor to help video referees review offside. FIFA tested it before the 2022 World Cup in Qatar. It is semi-automated because the tracking data and alerts are automatic, but match officials still confirm the kick point and make the final decision.

Q: How does semi-automated offside work step by step?

A: It follows five steps: detect the kick, select the nearest tracking frame, freeze the 3D player model, draw the offside line, and have an operator and the video referee confirm. Cameras track 29 body points per player at 50 Hz, and the ball sensor reports at 500 Hz. The whole chain is designed to finish in well under a minute.

Q: Is semi-automated offside better than traditional VAR lines?

A: It is faster and more consistent, but not automatically more correct on every call. FIFA has said average review time at the 2022 World Cup fell from about 70 seconds to about 25 seconds. Traditional VAR lines depend on a manually chosen frame and a calibrated broadcast view, so they carry more human variation and often a thicker line.

Q: Why was a goal disallowed when the offside looked tiny?

A: Because Law 11 has no margin of tolerance, so any part of the head, body or feet ahead of the line counts. The technology also has a small sampling gap of up to about 10 milliseconds, which is roughly 8 centimetres at sprint speed. Very close calls therefore look dramatic on screen even when the rule was applied exactly as written.

Q: What happens if the offside technology fails during a match?

A: Officials fall back to manual VAR review, drawing lines on broadcast footage. Expect a slower decision and a thicker, less precise line than the tracked 3D model gives. Tracking can degrade when many players crowd the box or when a ball sensor drops out, and the final decision still sits with the referee.

Q: Does semi-automated offside technology cost fans anything?

A: No, watching it is free, since it is built into the match broadcast and stadium screens. The cost sits with competitions and leagues, which pay suppliers such as Genius Sports to install and run the cameras and software. Whether a given league has it varies, so check your competition's rules before assuming the same standard applies.