The video assistant referee (VAR) was heralded as a major success at the World Cup finals this summer, and now it has been introduced fully in almost every top European League. Only the Premier League is stalling over its introduction, while UEFA is considering implementing it from the quarterfinals of the Champions League.
But how is VAR getting on in La Liga, the Bundesliga, Serie A, Ligue 1 and the Primeira Liga -- as well as Major League Soccer, where it's been in use since March after an initial trial last year?
La Liga
Number of key incidents reviewed by VAR this season: 364
Number of incidents correctly overturned after review: 10 overturned. 354 decisions approved (97.2 percent)
VAR has been used in all 29 league games played, with an average of 12.55 reviews per game. Only three incidents have been reviewed by the referee using the pitch-side monitor, while VAR has recommended seven incidents for review. Ten referee decisions have been overturned after reviews: seven goals -- five for offside, one for a previous foul and a goal/no goal situation -- two penalty decisions and one mistaken identity.
While it's early in the season, what has emerged is that VAR has pacified the game. Not since the 1991-92 campaign in Spain's top flight have there been fewer cards shown after three rounds, with an average of 4.34. Only one of the cards given was for simulation.
"We've had a few yellow cards that have not been shown and others that should not have, but the overall picture is extremely satisfactory," Spanish referee technical committee president Carlos Velasco Carballo said.
VAR has generally made games longer but Velasco Carballo says referees have improved since the opening round of games with respect to being more precise regarding stoppage time. Improving communication between the VAR and the match referee, due to crowd noise, is still a work in progress to reduce delays.
While the biggest criticism of VAR is that technology disrupts the flow of game, including affecting goal celebrations as Barcelona striker Luis Suarez recently bemoaned, debates regarding refereeing decisions have decreased, making the game seem more just.
But there have still been controversies as to when VAR should be used. Sevilla coach Pablo Machin was fuming after VAR did not intervene during a crucial incident in his team's 1-0 defeat at Real Betis on Sunday. Sevilla lost Roque Mesa to a second yellow card in an incident where Machin believes his player had first been fouled by goalkeeper Pau Lopez, and hence his team should have been awarded a penalty.
"Perhaps it's better to referee from the BAR with a 'B' having a few beers," Machin said. Velasco Carballo responded by saying: "VAR only intervenes if it considers the refereeing decision unsustainable." In other words, if it were a clear and obvious error. -- Adriana Garcia
Bundesliga
Number of key incidents reviewed by VAR this season: No data given
Number of incidents correctly overturned after review: There is no information yet for the 2018-19 season, but last season a total of 76 key decisions were overturned and 99.25 percent of decisions made were correct. Some 26 penalties were awarded after video review, and 13 penalty decisions reversed. Disallowed goals accounted for 23 overturned decisions.
After initial troubles, a more transparent and focused system saw VAR earn more acceptance in the second half of last season.
While controversy was reduced as players, officials, media and supporters became more accustomed to the use of VAR, there were still moments when it hit the headlines. In the match between Mainz and Freiburg, players were called back on to the pitch after the half-time whistle for a penalty.
Also, Hamburg were denied a goal after an offside flag in Frankfurt but TV pictures were not able to clarify whether the player had been offside or onside. With the introduction of the calibrated offside lines (on television screens) this season, there won't be as many controversial offside calls for VAR to deal with.
Acceptance of VAR has grown despite a false start this season, when a red card shown to Schalke defender Matija Nastasic led to the demotion of the league's most experienced video referee, Wolfgang Stark. It was also called "a shambles" after the opening weekend.
The league now informs fans inside the stadium of decisions taken via VAR on the giant screens, and that has helped greatly with communication.
Going forward, the Bundesliga hopes to become even more transparent by showing reviews on TV screens in grounds. It could also form teams of VARs and matchday officials to ensure good communication between the control room in Cologne, where the VARs are based, and the stadiums.
While the adjustment period is still ongoing, the atmosphere around VAR has changed and it is now becoming just part of the game.
However, it is still uncertain exactly when contact is made between the VARs and the referees, with what constitutes a "clear error" very much still open to interpretation. -- Stephan Uersfeld
Serie A
Number of key incidents reviewed by VAR this season: No data given
Number of incidents correctly overturned after review last season: 117 (59 penalties, 16 red cards, 42 goals). The number of mistakes without VAR would have been 5.75 percent, whereas with it, this dropped to 0.89 percent. Also, over the course of the season, the average time for VAR decisions improved from 1 minute 22 seconds in the first three games to 31.5 seconds over the whole season.
Despite being part of Italian football for a year already, VAR continues to fuel discussion. Its implementation, mainly for offside decisions, has prompted the most controversy with several incidents from last weekend alone under the microscope. Or rather the calibrated, digital, line visible to the VAR on their screens to determine whether players are offside or not.
Two goals -- one for AC Milan and one for AS Roma -- were scratched off by the VAR, while two were also disallowed after being referred in Chievo's goalless draw with Empoli. Last season, these decisions would unlikely have been amended as offside decisions were more subjective, and referees did not tend to change their decisions when they were so marginal.
Since the World Cup, VAR has improved with these offside decisions now so accurate that referees just agree with what they are being told in their earpiece, and players are not protesting either.
Indeed, acceptance of the technology and its decisions have led to fewer protests, including from Empoli coach Aurelio Andreazzoli, whose side would arguably have beaten Chievo without VAR. "I'm in favour of fair results and I've always been a fan of VAR," he told RAI radio. "This time it has penalised and upset us, but we have to accept it. If they've ruled [the goals] out, then it means they were offside."
In a league where refereeing decisions would be discussed for days on end, VAR has brought an end to much controversy, allowing the focus to return to what really matters -- the game.. -- Ben Gladwell
Ligue 1
Number of key incidents reviewed by VAR this season: No data given
It all started so well. The opening game of the Ligue 1 season, Marseille against Toulouse, and VAR - introduced in league matches in France for the first time in 2018-19 - was used to give the hosts a penalty that sparked a 4-0 win.
"We're not going to resolve all problems 100 percent," winning boss Rudi Garcia said. "But coaches and players will be more calm because referees will have the opportunity to correct a mistake."
Not so, Rudi. Fans and players have now learned that VAR "remains based on interpretation" -- as Reims boss David Guion pointed out -- and where there is interpretation, there is debate and a number of decisions being hotly contested.
Notably, Guingamp saw a goal that would have put them 2-0 up against Paris Saint-Germain ruled out after referee Clement Turpin saw a foul by scorer Nicolas Benezet on his VAR review that most -- also with the benefit of TV replay -- would not have given. Guingamp lost the game 3-1.
Referee Thomas Leonard was criticised for his non-use of VAR in last Sunday's goalless draw between Saint-Etienne and Amiens. While all parties were agreed he was right to chalk off a goal for the hosts after spotting a push with the help of VAR, Leonard came under serious fire for not reviewing incidents which would have given Saint-Etienne penalties.
"VAR has to go both ways," Saint-Etienne midfielder Yann M'Vila said. The home fans made their feelings clearer still, chanting: "And the video, the video, it's s---! The video it's s---!"
A long way to go for VAR in France -- Ian Holyman
Primeira Liga
Number of key incidents reviewed by VAR this season: No data given
Number of incidents correctly overturned after review last season: In 2017-18, a total of 76 incorrect refereeing decisions were reversed by VAR. (34 rounds, 18-team league)
Even allowing for teething issues as referees, players and fans accustomed themselves to the use of VAR, the overriding opinion regarding the new system's introduction in Portugal in 201718 has been almost universally positive. In a country where heated discussions raising suspicions about corrupt officials is a staple across all media every weekend, the fact such a radical change in how matches are refereed has given rise to broad agreement is a victory in itself.
The new campaign has started well for VAR with no major controversies. The highest-profile incident came in the third round of matches when a power cut at VAR's Cidade do Futebol headquarters in Oeiras on the outskirts of Lisbon meant the system was unavailable to the referee for 30 minutes during the Porto vs. Vitoria Guimaraes match. That spell coincided with Porto scoring an offside goal which was wrongly validated as well as the away side having a strong shout for a penalty turned down. If VAR was available it is probable both decisions would have been reversed. Fortunately, an early season storm of controversy was avoided as the visitors staged a remarkable fightback to come from 2-0 down and win the match 3-2, rendering the mistakes meaningless.
Nevertheless, Vitoria Guimaraes coach Luis Castro was rightly unhappy at seeing his side prejudiced by VAR. "Portuguese football has many points of instability and we can't have another one," he said. "When a referee is not available, a substitute is brought in. When VAR goes down, there has to be a back-up."
The only other time this season VAR has hit the headlines was in another Porto match as the Dragons were awarded a stoppage-time penalty for handball resulting in a late winner away at Belenenses. The referee had initially pointed for a corner. The handball looked extremely harsh given that the Belenenses defender had turned his back on a shot by Porto captain Hector Herrera just a couple of metres away from him. This potential flashpoint was mitigated, however, by the fact the referee had earlier awarded a penalty to Belenenses in practically identical circumstances.
As with all refereeing, what infuriates players and fans alike is a lack of consistency, and while one consequence of VAR is an increase in the number of penalties awarded (mirroring what we saw at the World Cup) the overriding feeling continues to be favourable in that the officials are now better equipped to ensure everyone gets equal and fair treatment. -- Tom Kundert
Major League Soccer
Number of video reviews in 2018: 95
Number of incidents correctly overturned after video reviews in 2018: 68
Number of correct decisions following video review in 2018: 84 (includes initially correct decisions that were maintained and incorrect decisions that were changed)
As MLS navigates its way through its second season with VAR, it seems not a week goes by without a player, coach or team executive pointing an incriminating finger in the direction of the system. There have been numerous complaints about inconsistencies about when VAR is used and the decisions that get made. Of course it's worth remembering that humans were making these decisions before VAR and they're still making them. But it would appear that a year after VAR was first used in MLS, some kinks are still being worked out.
That said, some interesting shifts in the way the game is being played - and refereed - are becoming apparent. A recent match between the Philadelphia Union and the New England Revolution saw Union forward Cory Burke released on a clear breakaway only for assistant referee Peter Manikowski to raise his flag for offside. Yet referee Drew Fischer, mindful of the protocol that encourages referees to let plays run to their conclusion, allowed play to continue. The only players to keep playing were Burke and Revolution goalkeeper Matt Turner, and Burke duly scored.
Upon review, the goal was allowed to stand, and even Revs manager Brad Friedel acknowledged that the call was correct and blamed his players for not observing the youth soccer adage to play until the whistle. It would seem that not all players have caught up to the way referees are making decisions in the age of VAR.
The support for VAR still seems relatively strong, though there have been suggestions for how to improve it. Earlier this season, a high-profile rant from Real Salt Lake manager Mike Petke that included a reference to "The Simpsons" was amusing and won the internet for a day, but it did highlight one sore spot with VAR, that being one of communicating to players, coaches and fans about how decisions get made.
Right now only the end result is communicated. Questions from reporters as to how decisions were arrived at often don't result in much more clarity. If MLS and the Professional Referees Organization - which has overseen VAR's implementation - can find a way to provide that information in a manner that doesn't result in more referee abuse, that may be the ticket to accelerating VAR's acceptance. -- Jeff Carlisle