The long-awaited rollout of the Video Assistant Referee (VAR) in football is being done with the intention of modernising the game, but its introduction has been far from smooth.
Now in operation across the biggest competitions in the world, featuring in the Champions League, the World Cup and Europe's top five leagues among others, it is a change which many are still getting used to.
While video refereeing was brought in with the noble aim of eradicating "clear and obvious errors" it hasn't always necessarily been able to do so, floundering in its remit on a number of occasions.
The Premier League was the last of the big leagues to sign up to VAR and, given how it has gone thus far, some in the league may feel their apprehension was well founded.
Goal takes a look at the issues to come up so far and whether it will be discontinued in the division.
Will VAR be scrapped in the Premier League?
VAR is unlikely to be scrapped in the Premier League any time soon, but it has been a constant source of frustration and debate since its introduction to the competition in the 2019-20 season.
Indeed, complaints regarding VAR have emanated from various strands of the football community in England, with players, managers, ex-professionals, pundits, fans and even officials airing grievances with the system over the course of the season.
Match of the Day presenter and former England striker Gary Lineker, for example, has been particularly vocal in his criticism, describing a contentious disallowed goal in Sheffield United's game against Tottenham in November 2019 as "VAR at its absurd worst".
Former Liverpool and Tottenham striker Robbie Keane, whose Republic of Ireland team potentially would have benefitted from VAR when Thierry Henry handled the ball in the play-off for the 2010 World Cup, believes that there are currently too many "grey areas".
"I was [in favour of VAR] at the start, but now I'm swaying towards 'no'," Keane told FAI TV . "Some of the decisions that have been made have been appalling, really."
There will be no changes in 2019-20, but the regularity of issues arising with VAR has been noted by Premier League bosses and pledges have been made to continue forensically reviewing the application of the technology in order to improve things in future seasons.
VAR at its absurd worst rules out a @SheffieldUnited equaliser for offside which is impossible to see one way or the other. WTF are they doing to our game?— Gary Lineker (@GaryLineker) November 9, 2019
"The message has got through to the league and to the referees' association that fans are unhappy, and many stakeholders in the game think we have to do a whole lot better," said Aston Villa chief executive Christian Purslow in an interview with the BBC following a November 2019 meeting between match officials and Premier League clubs,
Despite the volume of exasperation Premier League's head of VAR Neil Swarbrick rated the division's rollout of the video assistant referee at "seven out of 10".
"I think we're probably where we'd expect to be," Swarbrick told the BBC . "We always said it would take a while for everybody to be comfortable with how we're implementing VAR within the Premier League."
What are the main VAR issues?
When it comes to the use of VAR, the main issues are: the speed of decisions, the consistency of the technology's application and how details are communicated in the stadium during the game.
Ultimately, it is widely felt that VAR is having an adverse affect on the game by disrupting the flow of matches with delays which may not even yield the correct decision.
The main issues relating to decision speed and so on have also served to diminish the sense of enjoyment for both players and supporters when a goal is scored.
Brighton forward Leandro Trossard, for example, admitted that he has now learned not to celebrate a goal in case it is subsequently ruled out by VAR.
What are the main VAR controversies in the Premier League?
VAR has been in use in football since 2017 and controversy has travelled with it in whichever competition it is used, including the Premier League.
When Charlie Austin ranted about the need for VAR the season before it was rolled out in the Premier League, he probably didn't envision it would create so many issues.
Sheffield United 1-1 Tottenham (November 9, 2019)
A VAR decision in the November 2019 game between Sheffield United and Tottenham led Gary Lineker to ask incredulously: "WTF are they doing to our game?"
David McGoldrick's goal for the Blades was ruled out because his team-mate John Lundstram was deemed to have been in an offside position in the build-up.
Not only was the offside not clear from the footage, it took officials almost five minutes to arrive at their decision.
When describing the extended deliberation for Sky Sports News , former Liverpool star Phil Thompson screamed, "think of the punters in the stands!"
Brighton 3-2 Everton (October 26, 2019)
A VAR-led penalty call against Everton in a game against Brighton proved costly as the Toffees went from leading 2-1 to losing 3-2.
The decision was made to award the penalty to Brighton after Everton defender Michael Keane stood on Aaron Connolly's foot, but league officials subsequently admitted it was an error.
Everton boss Marco Silva was understandably upset and suggests that VAR has cost him five or six points, saying: "If they say to me, ‘Marco, sorry, it was not a penalty’, what does that change? I know it was not a penalty. It doesn’t help at all."
Aston Villa 1-2 Liverpool (November 2, 2019)
Did you hear the one about the armpit goal?
Liverpool Roberto Firmino was denied a goal by VAR in a game against Aston Villa because his armpit was in an offside position.
Liverpool's Roberto Firmino was flagged offside before putting the ball in the net against Aston Villa and the decision was confirmed by VAR— Premier League (@premierleague) November 2, 2019
The red line signifies Firmino and was aligned to his armpit, which was marginally ahead of the last Villa defender #AVLLIV pic.twitter.com/a2OnNWnz2E
Luckily for the Reds, they did not need the goal in the end as they won the match 2-1, but Jurgen Klopp was not happy about the explanation.
"We won 2-1, so it's now not that serious. But we are talking about serious moments, it's not right that we are sitting here talking about it and everybody wants to laugh," said the German coach.
"There's nothing to laugh about, to be honest. A manager can get sacked for losing football games.
"I don't want to make it bigger than it is. We just have to clarify it. I don't say anybody is doing it on purpose."