neutral zone

a portion of the football field which is the length of the football from one tip to the other when it is placed on the field prior to the start of the next play; no member of either team may be inside the neutral zone when the ball is snapped or a penalty will be called; a new definition of the neutral zone came into effect after a September 12, 2005 fight between the Philadelphia Eagles' Jeremiah Trotter and the Atlanta Falcons' Kevin Mathis that occurred prior to the opening kickoff; the NFL then instituted a rule that each end of the field from the end zone to the 45-yard line is reserved for one team, and that no player other than a kicker may be between the 45-yard lines prior to the game; the only exception to this rule is the center on the offensive team who may be inside the neutral zone while preparing to snap the football.