FIFA President Gianni Infantino has called video assistant refereeing "the future of modern football," lauding its role in the Confederations Cup to date. The system has had its detractors too.
Infantino called the Confederations Cup a "milestone tournament" on Monday - but not in reference to Germany's abnormally young squad or even to an international FIFA tournament taking place on Russian soil.
Infantino was in fact praising the landmark of the video assistant referee (VAR) being used at all Confederations Cup games as a prelude to the technology's World Cup debut next summer.
"I am extremely happy with VAR so far. We have seen how video assistance has helped referees make the correct decisions," Infantino said in a statement after Germany's opening game against Australia. "This is what VAR is all about … What fans have been waiting for over so many years is finally happening. This is a milestone tournament. Video Assistant Refereeing is the future of modern football."
The video assistant was called into action for a fifth time as Germany beat Australia 3-2 - sparing Bernd Leno's blushes somewhat by taking the attention off his second blunder of the game. Instead, uncertainty over whether the Socceroos' goal would stand dominated the moment.
'Are we okay to celebrate yet?'
It had already been used in four instances, including disallowing a goal from Portugal's Pepe against Mexico and another for Chile's Eduardo Vargas against Cameroon. Both were disallowed for offside, with the Vargas call a particularly close one.
Some have complained, however, that the process can take too long and even spoil key moments of the game. Much has been made, for instance, of the uncertainty now plaguing players' goal celebrations: checking for the offside flag and glancing at the ref is no longer sufficient before players know they can bolt to the stands and their fans.
German commentator Tom Bartels, from the public broadcaster ARD, was among the critics despite saying he was in favor of the new tech.
"Definitely unsatisfactory, at least so far. In principle I was a big supporter of the idea, but I think it hasn't really worked and isn't very transparent for spectators," Bartels said. "In general it's taking too long until decisions are reached, and very often the viewer can't work out what's the reason for the delay."
Some suggestions in this regard have included giving referees microphones, a common practice in several sports including rugby. This allows them to communicate why the decision is going for review, and explain the decision once it's in.
Human error still a possible factor
FIFA first adopted the technology at this past season's Club World Cup in Japan, and many major European competitions including the Bundesliga plan to introduce it next season.
Infantino did at least obliquely acknowledge some of the criticisms in his statement.
"The VAR tests during this Confederations Cup are also helping us to improve the processes and fine-tune communication," he said.
The technology should not be confused with goal-line technology - where the equipment is able to categorically answer a question of fact: did the entire ball cross the goal line or not? There is no human input in the process. VAR, on the other hand, relies on the person watching the tape using the extra evidence at their disposal to reach the right decision.
Although this situation is yet to be encountered in an on-air football game, video footage will prove inconclusive at times - a problem already well known to officials trying to pick through the bodies and see the ball on a crowded rugby try-line.