How the World Cup’s AI instant replay works

A new hyper-accurate technology, and referees' eternal quest for objectivity.

The offside rule, which requires attacking players to be behind either the ball or the last defender, is a rule that sounds objective, but has led to a lot of questionable calls, partly because it can only be judged from an individual perspective. Until now. Meet the new “semi-automated AI offsides technology” at the 2022 World Cup.

This technology relies on a sensor in the ball that relays its position on the field 500 times a second, and 12 motion tracking cameras mounted underneath the roof of the stadium that use machine learning to track 29 points in players’ bodies. In other words, FIFA is mo-capping players, just without the funny gray suits. And the whole system will alert referees when a player is offside. If you’ve been watching the World Cup, you may have also seen the motion tracking information being used to create an immediate 3D replay.

This system seems like it could be capable of eliminating “bad” offside calls, or maybe bad calls altogether - but its new precision will inevitably impact gameplay no matter what. And the first World Cup to feature it will show us exactly how.

[scone]

There’s nothing artificial intelligence about this technology. Really wish everyone would stop throwing that phrase around.

[idrisb]

Wish we could hear the officials’ conversations and decision making during these situations

[Chemson]

Can't imagine FIFA 2077
- AI referees
- AI coaches
- Full of bugs

[ThePositievx]

I came for AI, I found the explanation of offside.
Many thanks Vox.

[manubeckerman]

There is still a problem with the semi-automated VAR, tho. In the Saudi Arabia-Argentina game, Lautaro Martínez scored a goal that was ruled out because he was supposedly offside, but after the match people noticed that the semi-automated VAR was putting him offside because it was taking into consideration the center back that was just beside him, and it was not considering the Saudi left back that was putting him in the onside zone. Mistakes likes this MUST not happen, specially in a World Cup.

[CRZYvidz]

Off side rule being automated is an example of imposing a rule over it's original objective, in this case, off side rule intention is to prevent an unfair advantage of the attacker over the defending team. Having the tip of a finger from a hand or a milimiter of hair passing over the strict line of the defender does ot imply an advantage for the attacker and might be due to just a natural body movement, that might be the main reason for fans to hate the AI VAR system, maybe changing rules to prevent the attacker from having his point of support/supportig leg and torso over the line (or something similar) might be a more suitable parameter while still being just as objective

[codythomas]

An error happened in the US vs Wales game. The whales player intentionally passed the ball backwards to a US player who was offside. He was then fouled in the box but the AI determined the play was offside because it was not capable of determining intention. (It’s not offside if a defender makes an intentional touch to the opposing team whose offside). So instead of a foul being called and penalty given, the offside was called first and no review was done

[plkrtn]

"In an early match between Qatar and Ecuador"

Yeah. So early it was the first match 😂

[KainGerc]

Offside call is relatively objective (even if it gets decided on a matter of centimeters), but decisions based on stuff like fouls or handballs still get really heated debates

[mercurymercury]

For the next fifa the ball will be updated to feel pain and start yelling when an offside happens

[liliq.]

"So, the simplest way of explaining offsides is..." procedes to give the weirdest explanation of what offside is. Also, it would still happen today, because it does.

[felipe_marra]

It's so precise that eliminates goals by differences so subtle that it loses sense

[letsgoooooo]

As a casual football watcher (only during worldcups), i was soo confused this year by 'offside' decisions, thanks for expalining what this term means and how the AI tech works this year

[Thomas-gvzl]

Why is everyone forgetting the most important part..."WHEN THE BALL IS PLAYED"

[denwest]

Yeah, but offside was created to determine if the attacking team had an advantage. How is being 2 centimeters with your kneecap in offside an advantage?!. In my mind, there should be a rule change, where for example the attacking player has to be at least some amount in in front.

[neilsamuel]

Guys, you can't just put "AI" in front of anything. That's just motion tracking.

[zzzx]

wow, the story, the animation, they are stunning! thanks for the quality u guys made. + 1 sub

[valeg]

How did y’all know I was wondering this the whole time 😭

[kitanat]

Man, this whole World Cup is just reminding me how much I don’t like the current offsides rule. Why do the inches or centimeters matter? If a good ball is coming over the top or through, that player is getting to goal regardless of even a half a meter. How is a player supposed to measure centimeters in real time? How is a lean more advantageous for the attacker?

For the health of the game, I really think they should simplify the rule and make it easier to call such that refs can easily make the call without an entire computer program having clarify and dragging back goals and killing momentum and morale. At lower levels, do we just suffice with the eye-test offsides until we get counted off by a shoulder or knee by technology at the highest level? Then again, refs always just give the benefit of the doubt to the defenders, so you really shouldn’t be close at all to be safe.

So, in my opinion, they should either revert the offsides rule back to when you had to be clearly behind the defender. Or (what I’d prefer), you have the Arsene Wenger rule where you just need one body part being in line with the last defender. This actually really wouldn’t be that hard to recognize because most players making runs are watching the defender as a reference point and they would be timing their runs accordingly either way. Just my thoughts.

[mattbrown]

Any discussion of offside like this must include a discussion of overlapping body parts. Can the attacking player’s finger be offside if the rest of him is onside? Head? Foot? Knee? That’s what these calls come down to.