At this year's World Cup in Qatar, VAR will once again be used to assist referees during tournament matches.
While use of the video assistant has become commonplace in the Champions League, Premier League and Europa League, the referees in the control room have another tool in their arsenal to help them make decisions in the Middle East. The semi-automated offside technology is said to be able to make decisions quicker during matches.
It has already been the centre of some controversy at the tournament. In the opening match it helped rule out Ecuador's goal against Qatar inside four minutes and it also played a part in calling three Argentina goals against Saudi Arabia offside.
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But how does it work? MEN Sport has taken a look.
What is semi-automated offside technology?
FIFA approved what is known as 'limb tracking technology' to help officials make correct offside decisions during the World Cup for the first time. Although this is its debut in the prestigious tournament, the technology has undergone several trials over the last few years including in the Club World Cup this year.
How does semi-automated offside technology work?
In order to work, FIFA has installed 12 cameras in each of the stadiums which track the ball during the 90 minutes. The technology also uses data points on each of the players, while a sensor inside the ball is used to chart whether a player is on or off.
All of this data is sent to the control rooms 500 times per second. When a player is deemed to be in an offside position, the control room is alerted.
Before the VAR officials communicate with the referee, they check the decision manually to make sure that the player is definitely offside.
Once the decision has been made, a 3D graphic of the incident is shown to fans in the stadium and at home. FIFA claims that the call will only take longer than 25 seconds, the average VAR wait time for an offside decision, if there are multiple elements at play.
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