Currently making waves throughout European football, VAR — or Video Assistant Referee to give the concept its full name — was introduced in the Bundesliga for the 2017/18 season, and was available for all 306 top-flight fixtures.
bundesliga.com lays out what VAR is and how it is being used to make football a fairer sport.
How does it work?
Each Bundesliga game has a VAR, who sits in the VAR studio in Cologne and can quickly review incidents that occur in order to help the referee on the pitch. After watching TV replays, the VAR gives their opinion to their counterpart inside the stadium via the earpiece worn by match officials.
Watch: How Video Assist works
Which incidents are looked at?
There are four clear cases in which a VAR can review incidents via TV replays.
Was a goal wrongly ruled out for offside or given when a player was offside? Was a foul committed or some other rule breached in the scoring of a goal?
- Red cards
Is the sending-off justified? Has any unsporting conduct occurred behind the referee's back or off the ball?
Is the decision to award the spot-kick correct? Should one have been given for a foul not spotted by the match referee?
- Yellow/red cards
Is there a case of mistaken identity?
Who has the final say?
The VAR can only give their opinion. The match referee has three options when they hear what their colleague has to say:
- leave their decision unchanged;
- accept the VAR's suggestion regarding a decision;
- watch the incident again themselves via a TV screen inside the stadium.
When was VAR used for the first time?
Tobias Stieler was helped by Dr. Jochen Drees, the very first VAR for a Bundesliga game, when Bayern Munich kicked off the 2017/18 league season with a 3-1 win at home to Bayer Leverkusen. The VAR was called on 12 times in the match, helping to spot a foul by Leverkusen's Charles Aranguiz on Robert Lewandowski that led to a penalty being awarded to Bayern that otherwise would not have been given.
Watch: Referee Tobias Stieler reflects on his historic use of VAR