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: How Manchester City were robbed of the chance to win the game against Tottenham Hotspur, plus penalty decisions between Chelsea and Brighton & Hove Albion, and possible spot kicks for Arsenal and Nottingham Forest.
Play stopped on Grealish counterattack
What happened: The game was into added time when Emerson Royal tripped Erling Haaland in the centre of the park. Referee Simon Hooper paused for a second as Haaland regained his feet, before the striker got to his feet and played Jack Grealish through for a run on goal. But Hooper stopped the play and brought it back for the free kick (watch here.)
Review: It's not a decision that's covered by VAR, but it was by far the biggest refereeing incident of the weekend.
All referees will incorrectly stop play instead of giving the advantage to the attacking team a few times a season, but not in added time of the biggest game of the weekend when the scoreline is level.
Hooper plays the advantage, but changes his mind with the ball in flight as it is above Grealish and the Tottenham defenders. The referee mistakenly thinks the ball isn't of sufficient quality for Grealish to run on to, yet it becomes clear immediately after he has blown the whistle that the England international may have been through. Hooper's first instinct on the advantage was right, but he's then blown too early to pull it back having misjudged the pass. By that point it's too late.
Of course Hooper got this badly wrong, and we'll never know if Grealish would have got through for a shot on goal or if one off the three defenders, perhaps Ben Davies, would have made a challenge. The Spurs players stopped at the point of the whistle, which may give the impression that Grealish had a greater chance than he did have, but snuffing out the possibility of a match-winning chance is a big error.
Hooper had a good game up to this point, but the only discussion over his performance will be this mistake in a crucial situation.
Despite a high-profile error on the first weekend of the season, when Hooper failed to award an added-time penalty to Wolverhampton Wanderers at Manchester United, he is viewed as one of the most improved Premier League referees over the past year. Towards the end of last season he was given a number of key games, including this same fixture (which City won 4-2), the Merseyside derby and Manchester City vs. Liverpool. This season he was in charge for Tottenham Hotspur's controversial 2-1 win at home Liverpool, when there was a VAR error out of his control to disallow a Luis Díaz goal for offside. Last weekend he was the referee for Newcastle United vs. Chelsea, before being given this City-Spurs game.
Haaland was booked for dissent immediately after the incident, but the Football Association won't look at his furious reaction at the full-time whistle as well as his "WTF??" tweet in response to a video of it. Man City will be charged as the club failed to ensure their players do not behave in a way which is improper.
Possible penalty: Milner challenge on Mudryk
What happened: Mykhailo Mudryk broke through into the area in the 61st minute and went down under a challenge from James Milner. Referee Craig Pawson waved away the Chelsea player's penalty appeals and stopped play for treatment for goalkeeper Jason Steele while the VAR, Jarred Gillett, began a check for a possible penalty.
VAR decision: Penalty awarded, scored by Enzo Fernández.
VAR review: There's probably enough in the nature of the challenge for a VAR spot kick to be given, but it will split opinion, specifically about where the threshold sits with clear and obvious.
We see similar challenges when players are running side by side and a penalty isn't awarded, and we're told that the on-field decision will stand whichever way it's been given.
Milner, however, does seem to bundle into Mudryk, rather than it being two players running together, and he does trip Mudryk.
The law over denying an obvious goal-scoring opportunity (DOGSO) was changed slightly this season, to say that an attempt to play the ball and a challenge for the ball are both covered under double jeopardy. It means fewer red cards will be shown for DOGSO incidents inside the penalty area, with Milner cautioned as a result.
Possible penalty overturn: Handball by Colwill
What happened: Brighton & Hove Albion thought they had been given the chance to equalise 10 minutes into added time. A cross was played in by Simon Adingra and it hit Levi Colwill, with the ball going behind for corner. Pawson took a few seconds before pointing to the spot for a penalty (watch here.)
VAR decision: Penalty cancelled.
VAR review: A quick overturn from the VAR, with the referee mistakenly thinking the ball had hit Colwill's raised arm when it actually smashed into his face.
But there was a mistake with the restart -- Brighton should have had a corner and the chance to equalise from the set piece.
As the ball had already gone behind before the whistle was blown to stop play, Pawson should have restarted with a corner kick to Brighton after he had overturned his decision at the monitor. Instead, play got back underway with a dropped ball to Chelsea goalkeeper Robert Sánchez, which is the correct protocol if the penalty had been awarded with the ball still in play -- which is usually the case.
Situations where play would restart with a corner after an overturned penalty are extremely rare. But Brighton boss Roberto De Zerbi will feel aggrieved that VAR decisions have gone against him yet again -- first the penalty, which many will feel wasn't clear and obvious, and then failure to restart with a corner, instead giving the ball back to Chelsea, when Brighton needed a goal.
Coincidentally, it's the second time in recent gameweeks that a handball penalty has been mistakenly awarded in these circumstances, after Fulham's Timothy Castagne was wrong penalised at Aston Villa when the ball hit his head and went behind. Play also restarted with a dropped ball in this instance, though it was a borderline case whether or not the whistle was blown before the ball went out of play.
Protocol over the correct restart in these circumstances will no doubt be reconfirmed to all officials.
Possible penalty: Doucouré foul on Yates
What happened: Nottingham Forest wanted a penalty in the 73rd minute. A corner was played in from the right and Ryan Yates appeared to have his shirt tugged by Abdoulaye Doucouré as he ran across the area. Play carried on and Felipe fired a shot wide off the post. Referee Paul Tierney didn't give anything but it was looked at by the VAR, Michael Oliver.
VAR decision: No penalty.
VAR review: Holding or grappling takes place on every set piece, among many players, so penalising all contact isn't realistic. It's defined as being when "a player's contact with an opponent's body or equipment impedes the opponent's movement," which is hugely subjective not only for the offence itself, but only when the threshold is crossed for a clear and obvious error with VAR.
Unless all examples of holding of any kind are penalised with penalties there will never be perceived consistency, especially as the VAR looks to get involved only when the holding has a material impact upon the play -- does the attacker have a genuine attempt of challenging for the ball with limited holding?
Previous examples where penalties have been given have involved a defender having his arms around the attacker, rather than holding onto the shirt. That was the case last weekend when Nottingham Forest had holding penalties awarded for and against them against Brighton.
But the flight of the ball suggests Yates would have had a chance of challenging for the header if his shirt hadn't been held back, so this could be logged as a missed intervention by the Premier League's Independent Key Match Incidents Panel -- though it's a borderline call.
Possible penalty: Foul by Kilman on Jesus
What happened: In the 48th minute, Gabriel Jesus looked to meet a cross by Takehiro Tomiyasu and went down asking for a penalty, claiming to be held back by Max Kilman. The VAR checked for a possible spot kick.
VAR decision: No penalty.
VAR review: In comparison with the possible penalty to Forest, this is unlikely to be viewed as an error by the VAR not to get involved.
While there is some holding by Kilman, it's questionable whether it has enough of an impact on the Arsenal striker.
Possible handball penalty: Dalot
VAR decision: No penalty.
VAR review: Dalot had his arm by his side close to his body anyway, but there is an automatic exemption within the handball law that if a player heads or kicks the ball onto his own arm -- even if it's outstretched away from his body -- there should be no offence.
The logic is that a player cannot be gaining any advantage from hitting the ball onto their own arm in making a clearance attempt.
It's viewed differently if the ball is deflected onto the arm when making a block, as that is stopping the path of a ball played by an attacker; in this case arm position would be the important factor.
Indeed, there was another penalty appeal in the 78th minute when Aaron Wan-Bissaka tried to make a block, and the ball came off his thigh and onto this arm. As his arm wasn't making his body bigger it was a correct decision not to intervene with a spot kick.
Possible red card: Schar challenge on Fernandes
VAR decision: No red card.
VAR review: Schar should have conceded a free kick and been cautioned, but the contact on Fernandes was on top of the foot.
While the VAR does look for buckling of the ankle as evidence of excessive force as part of the assessment, this is unlikely to be the case when a player is stepping into a challenge rather than stretching.
There's no prospect of the VAR intervening on contact of this nature to advise a red card.
Possible offside overturn: Maguire on Antony goal
VAR decision: No goal.
VAR review: The ball touched the chest of Harry Maguire, who was in an offside position, on its way into goal, so it was an automatic and clear offside offence.
However, even if the ball hadn't made contact with Maguire the goal should still have been disallowed. Maguire had tried to evade the ball as it went past him, which would have been an obvious action which impacted goalkeeper Martin Dúbravka.
Possible foul: Tsimikas on De Cordova-Reid
VAR decision: Goal stands.
VAR review: There's an argument for a foul if given on the field, with Tsimikas jumping into Bobby De Cordova-Reid to win the ball. But it would have been hugely controversial had the VAR got involved to disallow the goal for this kind of 50-50 challenge won by the Liverpool player.
Possible disallowed goal: Encroaching on restart
What happened: Burnley took the lead against Sheffield United after just 15 seconds through Jay Rodríguez, but the striker appeared to already be in the opposition's half before the kick off was taken.
VAR decision: No intervention possible.
VAR review: The VAR is unable to get involved in any restarts of play, even if it results in a goal.
So even though there is a technical infringement, the goal cannot be ruled out.
We saw this happen last season too when Bournemouth scored from the kick off at Arsenal.
Possible red card: McBurnie for foul on O'Shea
What happened: Sheffield United forward Oliver McBurnie tried to shrug off Dara O'Shea with his arm in the 37th minute, with referee Chris Kavanagh showing the yellow card. The VAR, Stuart Attwell, checked for a possible red.
VAR decision: No red card.
VAR review: Very much the case of an "orange" card for McBurnie and there's a case that he throws his arm into O'Shea as he jumps for an aerial ball, and if the referee had shown the straight red card it wouldn't have been overturned.
McBurnie didn't last much longer, shown a second yellow card nine minutes later for a similar offence on the same player. The Sheffield United player will now serve a two-match suspension as it's his second red card of the season.
Possible offside overturn: Soucek on Kudus goal
What happened: West Ham thought they had a second goal in the 46th minute when Mohammed Kudus swung a cross in from the right, and Tomás Soucek tried to guide it on but the ball went straight in. The assistant immediately raised the flag to disallow the goal for offside.
VAR decision: Offside.
VAR review: Although Soucek didn't get a touch on the ball as it went through to goal, his attempt to kick it was an obvious action which had to have an impact upon goalkeeper Sam Johnstone.
Again, this provides comparisons with the VAR error not to disallowed Man City's goal against Fulham.
Some parts of this article include information provided by the Premier League and PGMOL.