EP1944067

For detecting an offside situation during a soccer game, a referee (in particular a linesman) needs to determine whether an offensive player is behind a line, which line is determined by the last defensive player of the other team and thus moving, at the moment that the ball is kicked. In order for the referee to keep said offensive player in sight, a method and system is provided, wherein an observable signal is generated when the ball is kicked or otherwise touched by a player. Thus, it is prevented that a small time lag occurs between detection of the kick of the ball and detection of the position of the offensive player with respect to the position of the last defensive player.