Summary points
To apply the offside rule correctly in a football game, the referee must be able to keep in his visual field at least five objects at the same time—two players of the attacking team, the last two players of the defending team, and the ball
This is beyond the capacity of the human eye, which may explain why so many offside decisions are controversial
The use of modern technology such as freeze frame television to aid referees' decisions is necessary for the offside rule to be applied correctly
Mehr Details: http://bmj.bmjjournals.com/cgi/content/ ... /7480/1470
