Semi-automatic offside in Serie A: what it is and how it works

From 4 January 2023 the new system

The semi-automatic offside (Saot) arrives in Serie A and will make its debut in the Italian championship on 4 January 2023, when the tournament resumes after the Qatar 2022 World Cup. How does the system work? How many cameras are used? How much time does it take for decisions?

The system should offer additional support to referees and assistant referees in evaluating more controversial situations. After being successfully tested at the FIFA Arab Cup last year, the system has been used at the World Cup. The president of the FIFA referee committee Pierluigi Collina has explained in recent weeks that the goal is “to have more accurate decisions and also faster decisions in offside cases. I know someone has called it an offside robot: it’s not”.

The Saot is an extension of the VAR system already used in 47 countries around the world and in more than 100 competitions, including all FIFA tournaments. Ten dedicated cameras, as well as several television cameras, are set up in the stadium to track 18 data points of each individual player, giving their position on the pitch. The number of data points should increase to 29 points per player by the World Cup.

This data, collected 50 times per second, is then transmitted to an Avar specifically dedicated to offside decisions to check and make their recommendation to the Var and the on-field referee. This process takes place in real time and therefore means that decisions can be made on offside calls in seconds, through near real-time monitoring of the position of the players’ arms and legs.