What it is

Deep zones are the areas of the field far from the line of scrimmage that the safeties and cornerbacks protect. The defense splits the deep part of the field into halves, thirds or quarters, depending on the coverage.

In a game

Two deep defenders each take a half, as in Cover 2. Three take a third each, as in Cover 3, and four take a quarter each, as in Cover 4. The more players share the deep field, the smaller each zone is and the more help each defender has against a deep pass. The price is that fewer defenders are left underneath.

More detail

A zone is a promise to protect an area rather than a player. A deep defender stays on top of the deepest receivers, keeps his eyes on the quarterback and never lets anybody get behind him. Offenses attack the spaces between the zones, for example with a seam route between two deep halves.

The diagram

1. Two deep defenders split the field into halves.
2. Three deep defenders split it into thirds.
3. Four deep defenders split it into quarters.