Editing Cornerback (section)

===Zone===
In [[Zone defense in American football|zone coverage]], the cornerback defends an assigned area of the field. Many schemes and variations were created to provide defensive coordinators great latitude and flexibility which aim to thwart offensive schemes.

When a team is using [[zone coverage]], some areas of the field require special attention when defending against specific pass plays. They include the flats (to defend the screen pass and hitch routes), mid range zones including the void (to defend the "stop n go", quick post, fade, hook, curl, and "sideline" or "out" routes), and finally the deep zones (to defend the post/deep post, chair, streak, "fly", "go", bomb, or [[Hail Mary pass|Hail Mary]] routes). These are basic terms (perhaps the most generic) for the basic zones and routes which vary system to system, league to league, and team to team.

Advanced forms of coverage may involve "quarterback spies" and "containment" coverages, as well as various "on field adjustments" that require shifts and rotations; the latter usually initiated by the captain of the secondary (typically the [[free safety]]) during the quarterback's cadence.  At this time the captain attempts to "read" the alignment (pro set, split set, trips, etc.) of the offensive "skill players" (backs and receivers) in order to best predict and counter the play the offense will run. He will base his decision on past experience, game preparation, and a sound comprehension of his teammates strengths, abilities, and tendencies. These adjustments may change on a play by play basis, due to substitutions or even evolving weather or field conditions. For example, defensive coordinators may favor a tendency to play a less aggressive containment style zone coverage during wet or slippery field conditions to avoid problems associated with over-pursuit (when a defender takes a poor angle on a ball carrier and cannot redirect in time due to poor footing).