Video Assistant Referee causes controversy every week in the Premier League. But how are decisions made and are they correct?
After each weekend we take a look at the major incidents, to examine and explain the process both in terms of VAR protocol and the Laws of the Game.
In this week's VAR Review: Why Everton's overturned penalty against Manchester United is not as straightforward as you might think. Plus, a possible penalty for Aston Villa against Chelsea and red cards for Myles Lewis-Skelly and Illia Zabarnyi.
Everton 2-2 Man United
Possible penalty overturn: Challenge by Maguire on Young
What happened: Three minutes into stoppage time, a shot by Idrissa Gueye was saved by André Onana. As Ashley Young moved toward the rebound, he went down and appealed for a penalty. Referee Andy Madley pointed to the spot for a foul by Harry Maguire, which was checked by the VAR, Matt Donohue.
VAR decision: Penalty canceled.
VAR review: It was the big controversy of the weekend, with Manchester United rescued from almost certain defeat as the VAR stepped in to cancel a penalty to Everton.
Did the referee really make a clear and obvious error, or did the VAR overstep?
The answer lies within the context of the on-field decision, and once you know the process it makes much more sense.
It has to be separated into two parts -- and that's what's not immediately apparent.
The on-field decision
The cornerstone of the VAR review was the original on-field decision. Madley gave a penalty for a foul by Maguire on Young, so that's what the VAR checks.
Maguire placed a hand on Young's hip, but there was no hold or pull that would cause the Everton player to go to ground in the way he did.
Upper body contact is viewed differently. For instance, a penalty may stand when a player goes down when through on goal even if the contact from the goalkeeper is slight. But when a pull is involved, the VAR will overturn if the attacker's actions are embellished -- as was the case in October when Chelsea had a penalty canceled against Newcastle United when the VAR ruled that Dan Burn had not pulled back Christopher Nkunku.
It was a clear and obvious error to give a penalty for this and the VAR was correct to overturn the penalty.
If the VAR doesn't think there was a foul by Maguire, he cannot unilaterally support the penalty for another reason, in this case the actions of Matthijs de Ligt.
De Ligt's shirt-pulls
De Ligt grabbed Young's shirt twice, once at the side and then at the back. Had the referee given the penalty for the Netherlands international's actions there would have been no VAR review; to award the spot kick would not have been a clear and obvious error. But the referee incorrectly penalized Maguire, not De Ligt.
You must consider whether De Ligt's actions are worthy of a VAR review if the referee had given nothing.
Holding is an offense when it impacts an opponent's ability to play or challenge for the ball, so a pull of the shirt by itself isn't a penalty. The VAR will take into account how long the shirt has been held, and if the player goes to ground in a way which is commensurate to the act.
Penalties awarded through VAR this season have all been for extreme examples of holding -- save for the red card shown to Southampton's Ryan Fraser for denying an obvious goal-scoring opportunity (DOGSO).
Donohue decided that the holding was "fleeting" (we've heard this before) and Young threw himself to ground in an exaggerated way. Therefore, this didn't meet the threshold for a clear and obvious error for a penalty. It would be difficult to support as a standalone review, based upon past similar incidents.
Why wasn't the referee shown the correct angles?
Again, it's down to the original decision, and the reason the referee was sent to the screen.
The VAR showed the referee several angles involving Maguire because the review was to cancel the penalty for that offense. Madley agreed to rescind the spot kick after being shown these.
This wasn't about concentrating on the wrong angles, it was the opposite: showing the referee the angles related to his on-field decision.
However, the De Ligt incident wasn't ignored at the monitor. After accepting the Maguire review, Madley was shown the shirt-pulls by De Ligt from the "high behind" camera, offering the referee the chance to assess it without advising there was enough in it for a spot kick.
Perhaps the referee could have been shown the goal-mouth camera angle, but remember the VAR has decided that there is no clear and obvious error related to De Ligt. The referee could also have requested further angles after seeing the high-behind.
Shaka Hislop backs the referee's decision to overturn his own call to award Everton a late penalty in the 2-2 draw with Manchester United.
Verdict: Earlier this month, Tony Scholes, the Premier League's chief football officer, said he wants to get to a place where "full visibility and full audio of the conversation between the referee and the VAR" is played out live. It's vital that that happens. But after eight years with VAR, the IFAB appears no closer to allowing even trials.
In this case, hearing the interaction would have made a huge difference to the general understanding, even if you still didn't agree with the final outcome.
There was a clear and obvious error to give a penalty against Maguire, so this wasn't re-refereeing the game. But to those watching without the context of the review, it may look to be the VAR getting involved when the decision should stay on the field.
We saw a similar kind of review last season, which was also confusing because no one could be aware of what went on at the monitor. The VAR told the referee that Brighton & Hove Albion's Lewis Dunk had been pulled back by Brentford's Yoane Wissa and it should be a penalty, but prior to that Wissa had himself been fouled by Dunk. The referee was sent to the screen and shown the penalty infringement, and also the initial foul. Rather than a penalty, play restarted with a free kick to Brentford.
Possible offside: Build up to Beto goal
What happened: Everton took the lead in the 19th minute when Beto scored from close range, but there was an offside check which took 3 minutes and 20 seconds. What was the VAR looking at?
VAR decision: Goal stands.
VAR review: This took far too long, partly because there was doubt about whether Jesper Lindstrom had touched the ball to set the offside phase to Beto, though he wouldn't have been offside anyway.
There was also two close offside situations as the ball pinged around the box, but it's doubtful the players involved were having any impact on the move.
Verdict: The Premier League's new semiautomated VAR offside technology (SAOT) will be used for the first time in the FA Cup fifth round, but it wouldn't make a difference in a situation like this.
As there's no chip in the ball, there would still be a question of Lindstrom touching the ball, and the VAR would have to weigh the possible impact if other players were offside. SAOT would have no impact on these aspects.
Aston Villa 2-1 Chelsea
Possible penalty: Challenge by Cucurella on Bogarde
What happened: Aston Villa won a free kick in the 83rd minute, which was swung into the area by Marcus Rashford. In dropped to the edge of the 6-yard box and as Lamare Bogarde tried to react he went to ground under a challenge from Marc Cucurella. Referee Michael Oliver allowed play to continue, and it was checked by the VAR, Paul Tierney.
VAR decision: No penalty.
VAR review: One of the considerations for a possible offense is both players being involved in mutual holding. If that's present, there's no foul by either player and they are equally culpable.
Both Cucurella and Bogarde have a hold of each other's arms, and this is why the VAR chose not to intervene.
Verdict: This was a quick VAR check, and it could be that the VAR saw the players had their arms entwined so judged it didn't need further attention.
But what is not immediately apparent is that Cucurella was holding the Aston Villa player with both of his arms and prevents him from getting to the ball. Oliver may have been unsighted to this, but the VAR should have picked it up.
Unlike the "fleeting" shirt-tugs by De Ligt on Young, this is the kind of holding offence which should be the subject of a VAR review.
Arsenal 0-1 West Ham
Possible red card: DOGSO by Lewis-Skelly
What happened: Mohammed Kudus robbed Myles Lewis-Skelly in the 73rd minute, and the West Ham United forward advanced past the halfway line with Arsenal goalkeeper David Raya well out of his goal. Lewis-Skelly fouled Kudus, with referee Craig Pawson showing a yellow card. It was checked for denying an obvious goal-scoring opportunity (DOGSO) by the VAR, Peter Bankes.
VAR decision: Red card.
VAR review: Although Kudus was on the halfway line when he was brought down by Lewis-Skelly he had control of the ball and Raya was in no man's land; the West Ham United player would have had the chance to shoot at goal.
If Raya had been inside his area, there might have been some doubt because Kudus was in a wider area and he would have needed to get closer to goal to have a realistic chance of scoring.
The only other VAR red card for DOGSO this season was for another Arsenal player, when William Saliba saw red at AFC Bournemouth, and there are some similarities with the fouls happening a long way from goal. In Saliba's case, Raya was much deeper but backtracking into his area, and the play was in a central area with the ball positioned for Evanilson to run on to.
There were claims of a foul by Kudus on Lewis-Skelly as he won possession, but there wasn't enough in that to be seen as a clear and obvious error.
Verdict: A textbook DOGSO red card which really should have been identified by the referee at the time. But then isn't this what VAR should be fixing?
Bournemouth 0-1 Wolves
Possible red card: Serious foul play by Zabarnyi
What happened: Illia Zabarnyi stretched into a challenge on Rayan Aït-Nouri in the 29th minute, and he caught the Wolverhampton Wanderers player high above the ankle. Referee Michael Salisbury produced a yellow card, and it was checked for serious foul play by the VAR, Stuart Attwell.
VAR decision: Red card.
VAR review: Red cards when a player's foot has come off the top of the ball always appear controversial, the most high profile being Curtis Jones' red card for Liverpool at Tottenham Hotspur last season.
The perception is that if the ball has been played, a player shouldn't be penalized for accidental contact which may follow. But it's always how the player is making the challenge which determines serious foul play.
Zabarnyi was perhaps unfortunate, but he made contact high on the shin of Aït-Nouri because he went over the top of the ball -- not because he went through it. Ergo, the challenge was already high and wasn't solely determined by the foot coming off the ball.
Verdict: The challenge was at full stretch and he caught Aït-Nouri high on the shin, causing the player's ankle to buckle. This won't be recorded as an incorrect VAR intervention.
Man City 0-2 Liverpool
Possible offside: Szoboszlai and Jones on second goal
What happened: Liverpool scored a second goal in the 37th minute when Dominik Szoboszlai fired home from just inside the area. The VAR had to check two possible offside offenses within the move.
VAR decision: Goal stands.
VAR review: Szoboszlai was in an offside position from the initial ball over the top, but crucially the Hungary international had no interest in getting involved in the play and allowed an onside Mohamed Salah to run onto the ball.
There was a bigger question about the role of Curtis Jones, who was clearly offside when Szoboszlai took the shot.
Importantly, Jones wasn't in Ederson's line of vision to the ball, and Szoboszlai's shot went to the opposite side of where he was stood.
Verdict: Had the ball passed close to Jones, the midfielder could have been judged to be impacting the goalkeeper. That would also have been the case if Jones was closer to Ederson.
But this is much like Manchester City's winning goal at Wolves earlier this season, when Bernardo Silva was not in the line of goalkeeper's vision. John Stones' goal was ruled out on the field but was awarded following a VAR review.
Newcastle 4-3 Nottingham Forest
Possible penalty: Handball by Aina
What happened: Lewis Hall tried to put a cross into the box in the 28th minute, which was blocked by Ola Aina. Newcastle United players appealed for a penalty, but referee Jarred Gillett allowed play to continue. It was checked by the VAR, Peter Bankes.
VAR decision: Penalty, scored by Alexander Isak.
VAR review: It's only the sixth penalty awarded for handball in the Premier League all season -- far less than any other top European league or competition.
Each time it has been given, a player has either had his arm raised high, or fully extended away from the body.
Verdict: Aina is perhaps the most unfortunate to penalized, as he was jumping and the arm wasn't above shoulder height, but it still created an obvious barrier.
Forest later had penalty appeals of their own, including one against Lewis Miley but the Newcastle player had his arm tucked into his body.
Ipswich 1-4 Tottenham
Possible penalty: Challenge by O'Shea on Danso
What happened: The game was in the 64th minute when Lucas Bergvall played a pass for Kevin Danso in the area. Dara O'Shea came across and shoulder barged the Tottenham Hotspur player off the ball, but referee Tim Robinson gave a goal kick as the ball ran out of play. It was checked by the VAR, Chris Kavanagh.
VAR decision: No penalty.
VAR review: Can it be argued that O'Shea is trying to protect the ball to win the goal kick? He took a huge risk doing so in such a fashion.
It's a strong challenge and had the referee awarded a penalty it wouldn't have been overturned, but at the same time we haven't seen VAR penalties awarded for situations like this.
Verdict: There was a similar case two weeks ago when Beto claimed he had been fouled by Leicester City's Jannik Vestergaard, who came across with a strong challenge to push the Everton striker off the ball. The KMI panel voted that it should have been given a penalty on the field (4-1) but on a split 3-2 vote said it didn't reach the threshold for a VAR intervention.
Some factual parts of this article include information provided by the Premier League and PGMOL.