Cover 4 looks for all intents and purposes as Cover 2. We will begin with the Linebackers. Will will drop to the curl unless there is a number 2 wide receiver. (Tight Ends do not count.) If there is a number 2 wide receiver, the Will Backer will wall the number 2 receiver to the outside. Mike Backer will wall the Tight End toward the outside. The Sam Backer is playing the Flat . They have to play run first. The difference is the corner and strong safety to the 2 receiver side. They show cover 2 but on the snap they play man to man on the wide receiver and Tight End. The Corner and Free Safety are still playing zone on the backside along with the Linebackers. The coner backside squats and keeps outside leverage. He are looking inside at the QB. If the ball is not in the air on the QB's third step, they immediately open and run to the deep out squeezing the passing lane. The FS is playing center Field keeping everybody in front. The advantage is by the Strong Safety playing the TE when he sees run, he will basically become a fourth linebacker and comes flying up for run support.