 If the offense fails to gain a first down (10 yards) after 4 downs, the other team gets possession of the ball at the point where the fourth down ended, beginning with their first down to advance the ball in the opposite direction.Except at the beginning of halves and after scores, the ball is always put into play by a snap.Offensive players line up facing defensive players at the line of scrimmage (the position on the field where the play begins).