A defensive strategy in which two players, usually the safeties, are responsible for guarding an area deep down the field. Cover 2 can be played in conjunction with a man defense or a zone defense.
In a Cover 2 Man, the receivers are being guarded man to man by other players with the two safeties providing help over the top. In a Cover 2 Zone, the short area of the field is divided up by the other players while the deep players guard against a long bomb pass.
Cover 2 is one of the more common defensive styles in football today. It relies on using the free safety and strong safety to take away deep routes down the sideline and gives the rest of the defense a chance to guard aggressively against shorter routes. A signature of the cover 2 defense involves the cornerbacks lining up close to the wide receivers and aggressively jamming them up at the line of scrimmage.
It can be exploited with throws down the middle if a team has an effective quarterback and good receivers who can go across the middle. Ideally, a Cover 2 should take away any deep passes, and allow the defense to stop the run and defend the line of scrimmage more effectively.