Abstract: Broadly speaking, the embodiments of the present invention fill the need for a method of accurately determining if an offense soccer player is in an offside position. This is determined using a combination of sensors on the players and the ball which are then sensed using fixed sensors on the field. The instantaneous sensor readings are used to locate each player, offense and defense with respect to the location of the ball and goal posts. These data are analyzed using an algorithm on a computer which can then determine if the player was in an offside position.