VAR at the World Cup 2018: What is the technology being used in Russia and how does it work?

Videos could decide the result of the competition this year. And it will almost certainly prove controversial

The World Cup will put the greatest footballing nations on Earth to the test. But there is another trial happening, perhaps just as important and even more controversial: that of VAR, or the video assistant referee.

The technology is being used at the World Cup for the first ever time, and has the potential to fundamentally change games. It could decide the future of the tournament, by reversing some of the most important refereeing decisions in the game.

Proponents claim that VAR will ensure that decisions are fair and that the best team wins. But even those supporters admit that the technology is still at a very early stage – with supporters and referees still apparently confused about how it should actually be used.

Despite that complexity, the technology is fundamentally incredibly simple: it is an extra referee who watches the game and advises officials on decisions. In practise, though, it might be very complicated indeed.

How does it work?

There are 13 officials who can be chosen as the video assistant referee. They will all sit in a special hub in Moscow – no matter where the game is happening – and they will do so wearing their full kit, as if they were ready to jump onto the pitch at any time.

Of those, one will be chosen for each game, and they will have a team of three assistants.

In there, they will receive a stream from inside the stadium, which is made up of the view from a whole host of cameras – including slow motion ones – which the referees can flick between.

The VAR will watch the whole of each game. If they see something wrong, they can flag it to the referee; if the referee thinks something is wrong, he can get in touch with the VAR.

Either way, the VAR is only advisory. Any decision ultimately rests with the referee, even if he has advised the opposite way by the VAR.

A general view of the Video Assistant Referee's Room home of the VAR system to be used at all FIFA World Cup matches during the Official Opening of the International Broadcast Centre on June 9, 2018 in Moscow, Russia (Laurence Griffiths/Getty Images)

What can be referred to the video referee?

Fifa might have allowed the technology into the World Cup. But they have severely limited the kinds of decisions it can actually be used for.

In total, there are four different sorts of incident that can be reviewed:

• Goals. The system can be used to check if a goal actually went in, in the obvious way. But it can also adjudicate on the lead-up to the goal, not just the ball passing into the net – if an infringement would have stopped the goal being rewarded, then VAR can stop it being awarded.
• Penalties. This can go either way, being used to check whether a penalty should have been awarded and wasn't, but also reversing the decision if a foul is given in the penalty box.
• Red cards. If the referee has decided a foul has been committed, then VAR can be used to decide whether a red card should be awarded. This might be the most controversial thing that the video technology will be relied on for, for reasons we will get onto later.
• Mistaken identity. Probably the most vague but also important parts of VAR's responsibility, this will allow the additional referees to spot if the wrong player has been disciplined. If they are, the referee will be corrected. That should stop situations like the mix-up between Kieran Gibbs and Alex Oxlade-Chamberlain that saw the wrong player sent off during a match in 2014.

How do you know when it's happening?

The entire system of VAR is focused around the referees, not around spectators. Which means the priority is not on making clear when or whether the system is being used.

It can be engaged in one of three ways.

In some situations, the referee might simply get a message in their earpiece, indicating that a decision is being reviewed. They'll get word from the VAR referees, who might tell them to change or stick with a decision. Spectators might not even know this is happening, or just see the referee touch their earpiece.

Another sees the video process engaged more formally, and the referee will draw a rectangle in the air to indicate a TV. That can be triggered by either the referee or the VAR judges, who will again have a word through the earpiece. The decision will be relayed to the referee, who will then make the rectangle sign again and carry on with the match.

The final one is the most clear, but could be the most confusing and frustrating in the stadium. Referees will head over to a small reviewing station on the side of the pitch – making the TV sign as they do – where they will also be able to see the same replays that are being shown to the VAR officials. They'll then consult together and make their decision.

In all cases, the decision will be made clear in the normal way – by the traditional referee signalling the decision, in the same way as without VAR. They might make the rectangle TV sign in the air to indicate how the decision was made, but then will continue in the usual way.

What can spectators see?

Perhaps the strangest and most confusing part of VAR is the fact that spectators won't actually get to see any of the replays, or even necessarily know what is happening. At most, they'll see the referee make the TV screen sign and perhaps head off to watch the pitch-side review.

But viewers at home will get to see the same pictures the referees are being shown, so the decision should not be quite so shocking. (This only goes one way: the referees don't get to see any broadcast images, or hear any commentary.)

Does it make any difference to players?

In the more direct sense – that is, discounting any arguments about whether it will change the pace of games – VAR doesn't allow players to do anything specific. In fact, the only significant rule change is what players can't do: they must not make the VAR sign themselves, in the same way they can't pretend to hold up a yellow card to someone as part of a protest, and they can be booked if they try it.

Why is it so controversial?

It took a long time for VAR to be introduced. And that was partly because many people fear it could ruin the flow and feel of the game.

Critics suggest that referees flagging up decisions using VAR – and then taking time to review footage and make their decision – could cause disruptions in play. And they also suggest that it will take away the important nuance that is part of refereeing, butting into matches to decide on any incident that relies on shades of grey.

Proponents have dismissed that idea. Earlier this year, refereeing body PGMOL stressed that the system would only interrupt games when there were very clear problems – "the rule of thumb is essentially 'if it’s not clear and obvious, leave it', and 'minimum interference, maximum benefit'," The Independent's Miguel Delaney wrote at the time.

But in use, the technology has been far from clear.

At a friendly match between Italy and England just weeks ago, a bizarre decision saw the video referee award a penalty – but that fact came after minutes of unexplained contemplation, and was not very well communicated to spectators. That came after similar events at Tottenham, which saw Spurs have two games disallowed during an FA Cup game, but after a lengthy disruption to play.

Officials might now be more used to using the technology, and working together. But we won't know until a World Cup match is interrupted.

Are there any changes being made for the World Cup?

The previous confusing instances have led to some changes for this competition. Fifa will be able to use a special tablet to send information to spectators and broadcasters, which should hopefully give them a bit more of a sense of what is actually happening while decisions are being made.

Is it likely to make a difference to decisions?

A study released this week found that slow-motion videos and real-time ones mostly led to the same decisions: in the experiment, referees were 63 per cent right when they watched an incident slowed down, compared with 61 per cent at normal speed.

But it found that slowing down videos seemed to severely change the way that referees saw intention. Watching in slow-motion made them far more likely to think that a foul had been done on purpose – and therefore considerably more likely to give a red card.