This rule controls the action of the offensive team's current quarterback, and requires that the blocking/countdown rule not be in use. When teams are even, a "shift" (hand-off) between two offensive players begins the play. It takes a touch from a defender assigned to the quarterback (the "first touch",) to stop his initial forward progress and determine where the ball will be thrown from. The assigned defender is stuck to the quarterback, unable to act as a pass defender or hinder the quarterback in his search of a receiver.