Video Assistant Referee (VAR) causes controversy every week in the Premier League, but how are decisions made and are they correct?
After each weekend, we take a look the most high-profile incidents and examine the process both in terms of VAR protocol and the Laws of the Game.
Possible red card: Richarlison throws smoke bomb
What happened: After Richarlison put Everton in front just after the half-time break, a home fan threw a smoke bomb onto the pitch. As part of his celebration, Richarlison picked it up and threw it back in the direction of the crowd.
VAR decision: No VAR review.
VAR Review: A difficult one for the VAR team, led by John Brooks, because as soon as Richarlison scores their role is to review the attacking phase for any offence, such as a foul, offside or handball. It's for this reason there was no VAR review, as it was not picked up at the time.
Whilst it's not outside of VAR's remit to identify a red-card offence during a goal celebration, it is more for the match referee, in this case Kevin Friend, who should always monitor it for any over-exuberance that requires a sanction -- including removing the shirt and/or jumping into the crowd.
Should Richarlison have been sent off? Throwing any kind of object can certainly be seen as violent conduct, so Richarlison was running a huge risk.
Jamie Carragher of Liverpool was sent off against Arsenal in January 2002 when he picked up a coin thrown by a Gunners fan and hurled it back into the crowd, hitting a supporter. This was a clear case of a violent act and while he didn't face a Football Association charge he was banned for three games for the red card and fined £40,000 by his club.
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The question over Richarlison, which has yet to be answered, is where the smoke bomb landed. While it was sent toward the fans, Everton insist the player was throwing it out of the ground through the gap between the stands.
It's complicated by the ban on all forms of pyrotechnics inside grounds. Indeed, earlier this season Liverpool's Harvey Elliott was written to by the FA for merely holding a red smoke bomb following his side's Carabao Cup final victory over Chelsea.
The FA will look into the incident, and Richarlison is in danger of a three-match ban if he were to be charged, which would severely dent Everton's hopes of avoiding relegation. If he did throw the smoke bomb out of the ground, he might be lucky and escape with just a fine or censure for misconduct.
Possible red card: Ramsdale on Bowen
What happened: Jarrod Bowen was sprinting into the Arsenal half when goalkeeper Aaron Ramsdale came rushing out of his area. Bowen went down from Ramsdale's challenge but the West Ham United forward was booked for diving by referee Mike Dean.
VAR decision: The incident was reviewed for a red card on two possible counts -- denying an obvious goal-scoring opportunity and serious foul play. The first was discounted as Bowen was running away from goal, and it was decided there was no clear and obvious error on the tackle itself as Ramsdale made no contact with Bowen.
VAR review: Another interesting one on a point of Law, as there doesn't need to be contact with an opponent for a referee to dismiss a player for serious foul play. Indeed, Arsenal's Granit Xhaka was sent off at Manchester City in August when he made little to no contact on Joao Cancelo when he challenged with both feet off the floor. The difference in that case was the red card was shown by the referee, and not from a VAR intervention.
Bowen himself admitted to Dean that there was no contact and his yellow card for simulation was deserved. However, it can certainly be argued that Bowen had to take evasive action to avoid the challenge. Therefore, the better outcome would be that Bowen was not booked for his part in the incident.
An important factor for the VAR is that decisions are not taken on hypothetical scenarios, such as what would have happened if Ramsdale actually did make contact with Bowen in what was a forceful challenge. Therefore, the yellow card for the dive was not an incorrect decision from Dean, even though the incident itself could very easily have resulted in a red card.
That said, if Ramsdale had been sent off we would be having a similar discussion, but on the merits of a red card without contact.
Possible handball: Holding in build-up to Gabriel goal
What happened: Gabriel scored to put Arsenal 2-1 up in the 54th minute. Earlier in the build-up, the ball appeared to hit the arm of Rob Holding, before it dropped to Gabriel Martinelli to create the goal.
VAR decision: Goal stands, no deliberate handball by Holding.
VAR review: The Law governing handball directly before a goal has been relaxed over the past two seasons, meaning a goal will only be disallowed if the handball -- accidental or otherwise -- is by the player who scores the goal.
The only way the goal could have been disallowed is if the VAR decided it was a deliberate handball by Holding, and in this case his arm position was justifiable by his action (jumping for the header.) Correct decision to allow the goal under the current interpretation, though it may well have been ruled out two seasons ago.
VAR overturn: Penalty to Brighton
What happened: The score was goalless when the ball hit the arm of Wolves defender Romain Saiss as he attempted to block a cross.
VAR decision: The VAR, Michael Salisbury, advised referee Simon Hooper there was a handball from Saiss. The penalty was awarded, though Alexis Mac Allister could only hit the post.
VAR review: We have seen several similar incidents not lead to penalties via a VAR review this season, as Saiss' arm wasn't a long way out from his body.
The key difference here was the defender was deemed to have leaned into the cross, and then blocking it with his arm. If the ball had simply hit his arm, no penalty would have been awarded. That said, on another day with a different VAR you wonder if there might have been no overturn.
If the referee, Jon Moss, had given a penalty it certainly wouldn't have been overturned by the VAR, Jarred Gillett. As it was, Gillett decided that it was a subjective call by the referee and not a clear and obvious error. Son can count himself lucky as the game could have gone very differently had Leicester scored first.
VAR overturn: No penalty to Burnley
VAR decision: The VAR, Stuart Attwell, checked where the foul had taken place and advised referee Craig Pawson it was just outside the box. The penalty was rescinded and Burnley were given a free kick on the edge of the box.
VAR review: The position of a free kick or penalty is judged when the initial foul contact is made. So, a player could be fouled just outside the area and contact continue into the box. In this case, the foul contact on McNeil was outside the area and it was a correct decision to rescind the penalty.
It's different when there is a holding offence. When this continues into the box a penalty can be awarded even if the first contact is outside the box.
Possible penalty: Romeu on Gallagher
VAR decision: The VAR, Peter Bankes, decided that it was not a clear and obvious error to award a penalty to Gallagher, who had been stumbling just before contact from Romeu.
VAR review: Gallagher may not have completely had his balance when the challenge came in from Romeu, but the Southampton player certainly didn't get the ball so it was a surprise that the VAR did not advise a penalty review. The Premier League's high bar on interventions meant Bankes felt the threshold hadn't been met because Gallagher was not fully in control, and it seems a situation which would result in a penalty in other leagues.
Information provided by the Premier League and PGMOL was used in this story.