Types of Football Defenses
Cover two (and Tampa two)
The cover two defense was devised to stop the West Coast offense, which relies on short passing routes and running backs coming out of the backfield to catch passes. Rather than cover receivers man to man, the defensive side of the field is divided into zones, with each zone the responsibility of a safety, cornerback, or linebacker. The deep part of the field (the area starting about 15 yards from the line of scrimmage) is divided into two large zones, each of which is the responsibility of a safety. The safeties guard against receivers running downfield to catch long passes.
Meanwhile, the area between the line of scrimmage and the deep part of the field is divided into five small zones, each of which is the responsibility of a cornerback or linebacker. The idea is to stop the short pass, or if a receiver succeeds in catching a short pass, to keep him from gaining more than a few yards. If a receiver breaks a tackle and gets downfield, one of the two safeties for which the defense is named is supposed to stop the receiver from breaking off a long gain.