Cover 6 is a blend of two separate coverages: Cover 4 and Cover 2. It offers the ability to disguise, protect against the passing strength, and has safeties that are active in the run game.
Cover 4 uses four deep defenders and three defenders underneath. Typically, it uses man-coverage techniques within zone principles.
Cover 0 is an aggressive coverage that is usually tied to heavy blitz packages. It leaves zero deep defenders and utilizes man coverage.
Cover 3 is a zone defense with corners and safeties protecting the deep thirds of the field and four defenders covering the underneath zones.
Cover 2 is a zone coverage with two deep safeties and the rest of the defense responsible for five underneath zones.
Cover 1 utilizes one free safety in the middle of the field with underneath defenders in man coverage and one lurk defender.