Since the main goal is to disrupt the offensive play before it even develops, many blitz packages encourage cornerbacks to play tight man bump and run coverage to disrupt the wide receivers' release and prevent them from running their pre-assigned routes. The non-blitzing safety, usually the free safety, has an enormous amount of field to protect and is at a serious disadvantage if the blitz is unsuccessful and receivers threaten his coverage area or if the offense can quickly move the ball forward through immediate checkdown passes or draw plays. As such, he usually works for depth upon the snap of the ball, backpedaling into his assigned zone.