The optical tracking system was first tested at last year’s Arab Cup in Qatar, and the ultimate goal is for it to be fully in use for the World Cup in the Gulf state later this year.
Pierluigi Collina, chairman of FIFA’s referees committee, on Wednesday told reporters VAR had proved “very successful” since its introduction but conceded more consistency is needed.
“It’s not yet at the very, very top… the same speed decision-making process. Being fast and being accurate don’t work together,” Collina said at the Club World Cup in Abu Dhabi.
“It’s important the video officials get an accurate decision, but we are aware we need to reduce the time, particularly with offside.”
“Sometimes it takes a bit longer to assess an offside decision, particularly in very tight incidents,” he said.
“The goal is already celebrated, everybody is waiting and then there is a goal disallowed, or the other way round… and then after quite a long time there is the final decision.”
The data-driven, limb-tracking technology relies on a series of dedicated cameras and broadcast cameras around the stadium to give the exact position of players on the pitch, offering referees precise information within seconds.
To provide improved accuracy, the system currently generates 18 data points per player — tracking the various parts of the body to create a skeletal, three-dimensional model.
The aim is to increase that to 29 for the World Cup to provide further precision, according to the head of football technology at FIFA, Sebastian Runge.
Once a final decision is made, the artificial-intelligence driven technology turns the images into a 3D animation that can be displayed on the big screen at grounds.
“By taking that data, we can enter the 3D world and we can create animations, that can explain perfectly whether a player was onside, how much of that player was offside or onside,” said Runge.
“We put that in an animation that will be shared with TV and our giant screen operators and we can inform the spectators in a clearer way on offside and onside decisions.”
Despite the ever-growing influence of technology, FIFA insisted the match officials will always make the final call.
A dedicated VAR assistant is responsible for monitoring offside, checking incidents as they happen rather than waiting for a stoppage in play.
The assistant notifies the main VAR official, who makes the decision and then speaks to the referee.
“I know that someone called it ‘robot offside’; it’s not. The technology is simply a tool used by human beings,” said Collina.
“The referees and the assistant referees are still responsible for the decision on the field of play. The technology only gives them valued support to make more accurate and quicker decisions.”
Collina used the example of a goal ruled out for offside in Palmeiras’ 2-0 semi-final win over Al Ahly on Tuesday as an area where more can be done to keep fans fully informed.
“We were discussing before how to get the attention of the people in the stadium because if you don’t know (the animation) is coming… you don’t look at the giant screen,” he said.
“It’s not possible to get this image within the same stoppage of play. It takes roughly 30 seconds, that’s why it’s shown at the next stoppage of play.
“Maybe we need a way to alert fans to the image on the big screen.”