This technology tracks the ball using 12 dedicated tracking cameras and analyses up to 29 data points for each player, 50 times per second, to determine their precise location on the field.
All limbs and extremities that are important for determining offside are included in the 29 data points.
Including an inertial measuring unit (IMU) sensor in the match ball would add another crucial component in making close-offside calls.
Semi-automated offside technology (SAOT) is used in association football to help referees determine whether an attacking player is in an offside position.
The play can continue if the referee determines that the attacking player is not in an offside position.
If the referee determines that the attacking player is in an offside position, the play can be stopped, and the opposing team can take possession of the ball.
SAOT was first introduced into international football during the 2006 World Cup.
At that time, it was only available during group-stage matches. Since then, it has been implemented into more and more FIFA tournaments. In 2018, SAOT was implemented into all World Cup matches.