Semi-Automated Offside FAQ: What FIFA's VAR Actually Measures

Semi-automated offside technology (SAOT) has been in the headlines since the 2026 World Cup, but the public conversation is mostly heat. Here are the questions people actually search for, answered without spin.

How does semi-automated offside work?

Multiple ceiling cameras track 29 body points on each player at 50 frames per second, plus a sensor in the match ball. Software estimates each player's position in 3D space, applies the offside rule at the moment of the pass, and flashes an alert to the video room when it thinks an attacker is beyond the second-last defender.

Is the animation on the broadcast the evidence?

No. The 3D animation is a visualization of the same positional estimate the software already produced. It is not an independent second measurement — it inherits every error from the underlying tracking. A crisp graphic can feel like proof; it isn't.

What is the tolerance on the measurement?

The Premier League operates its system with a 5 cm tolerance. FIFA's auto-alert only fires above 10 cm. Yet individual verdicts are reported in millimeters. Independent analysis suggests reliability lands around 9 in 10 at the tightest margins — which sounds high until you remember tournaments turn on the 1 in 10.

Why is it called semi-automated?

Because a video referee confirms each output before it becomes the on-field decision. FIFA presents this as human oversight. In practice, no official has ever publicly reversed a positional call, which makes the "confirmation" closer to endorsement than review.

Has the system been independently audited?

Not publicly. There is no published error rate, no external verification report, no shared test methodology.

What happens if the system is wrong?

There is no appeal path for a positional call. The verdict stands, the match continues, and — as Iran discovered at the 2026 World Cup — a tournament can end on a call no independent party has verified. The full case study is in A Verdict Without Evidence.

Why does any of this matter outside football?

Because the same architecture — unauditable systems issuing high-stakes verdicts with no published error rate — now runs in credit scoring, hiring, benefits eligibility, and pretrial risk assessment. If we accept the pattern in sport, we accept it everywhere.

What would fix it?

Six things: publish the error rate, declare the decision rule, attach a confidence score to every verdict, define the operating limits, keep an auditable log, and submit to independent verification. None of them are radical. All of them are missing.