Football 101: Zone Coverages

I do not have a humorous anecdote about zone coverage's, as I learned far more about zones from studying football and the wonderful world of Madden than I did playing guard for an offense that ran the original one back spread in high school.  Today we will dive into a basic description of the most common zone coverage's used in football today; the cover 2, cover 3, and cover 4. 

The numbers 2,3,4 refer to the amount of defenders in the secondary that will be playing deep coverage and preventing the completion of long passes.  This is why you will often here these referred as "2 deep" and "3 deep" zones. 

The advantage of zone coverage allows the defenders to have their eyes on the quarterback and the development of receivers routes.  Man coverage often results in defenders running with their back turned, relying on reading the receivers mannerisms to see if the ball is coming their way.

The Cover 2 Zone:

The Cover 2 Zone involves the two safeties playing deep zone coverage and five defenders playing zones underneath. 

This is the absolute simplest form of the Cover 2 defense.  The defense is designed to shut down intermediate throws and force short passes.  It also includes many variations that can confuse quarterbacks. In the NFL, you will mostly see the "Tampa 2" defense.  In the Tampa 2, the middle linebacker drops to the deep middle, covering the seam route. This gives the 2 deep coverage the advantages of 3 deep coverage.  It is also designed to help defend against the ultimate cover 2 zone beater, the "Four Verticals".  The most effective way to beat a zone defense is to stretch it to create space.  By sending an four receivers downfield, it attacks the space covered by just two defenders. 

Cover 3:

The NFL is a league of fads. A decade ago, everyone ran either the Tampa 2, or the 3-4 "Blitzburg" zone blitz scheme. After the Seahawks won a Super Bowl and led the NFL in defense four years in a row running the cover 3, the cover 3 is back in fashion.  The cover 3 involves breaking up the space downfield into thirds.  The cornerbacks take the outside thirds on their respective sides and the middle third is manned by the Free Safety. The cover 3 allows the strong safety, the bigger of the two safety positions, to play closer to the line of scrimmage and assist in run support. 

The cover 3 is best defending throws downfield and it forces the offense to complete short throws to move downfield. The cover 3 is most vulnerable in throws to the flat as you can see in the diagram above. Schematically, it is vulnerable against seam routes, although teams like the Seahawks use great athletes at linebacker and safety to close off the seam route. 

Cover 4

The cover 4, also called quarters coverage, involves splitting the back end of the secondary into fourths.  The straight cover 4 zone is typically associated with the "Prevent" defense as it is designed to give up short and intermediate throws in order to make it nearly impossible for the offense to complete deep passes. 

All of these coverage's have alterations that make them fluid and adaptable to modern offenses.  Michigan State has been running a flexible cover 4 to great success for much of the last decade.  The cover 4 switches from press man to zone based on the offensive alignment and route combinations.  The Seahawks version of the cover 3 is similar, with checks built in to adjust to each offensive look.  Yet, this is football 101, those intricacies can be addressed at a different time in a different column. Now, come the fall, you may be able to understand the what and the why of pass defense just a little bit better.