Semi-automated offside technology is a support tool that automates key elements of the offside decision-making process for the video assistant referee (VAR).
It will be used in close offside calls – to either confirm or recommend a change to the referee’s call on-field – as is currently the case with VAR.
To determine close offside calls, the VAR currently needs to work with replay operators (RO) to manually determine the "kick-point" for the offside decision and then "draw" calibrated lines with a crosshair on the relevant defender and attacker, using multiple camera angles.
Once the lines and kick-point are determined, an "offside" or "onside" decision is generated.
Semi-automated offside technology will suggest a "kick point" and automatically create offside lines on the second rear-most defender and the relevant attacker – saving significant time in determining whether a player is onside or offside.
Once the semi-automated offside technology-generated outcome has been reviewed and approved by the VAR, a decision visual will be automatically generated and distributed to fans in the stadium and to the media.
How does the system work?
The system uses up to 30 newly installed cameras mounted around Premier League stadiums – with several capturing footage at 100 frames per second, twice the frame rate of typical broadcast cameras.
The cameras track the exact movement of the ball as well as up to 10,000 surface "mesh" data points per player - meaning the technology will track to see if any attacking player involved in the build-up to any incident was offside.
These are then "flagged" automatically in SAOT software to the VAR and SAOT operator.
Why isn’t it fully automated?
The technology is "semi-automated", meaning there is human input as the VAR still needs to confirm the decision and that the SAOT system has accurately identified the "kick-point" and the correct players with the correct part of the body – and the outcome of the SAOT.
VAR will also need to determine whether the referee needs to conduct an on-field review for "subjective" offside calls – such as cases where deliberate play by a defender needs to be considered, or where an attacking player doesn’t touch the ball but could be interfering with an opponent while in an offside position.
