What it is

Cloud is a Cover 3 variation in which one cornerback plays the flat instead of dropping deep. The safety on that side takes his deep third.

In a game

The cloud cornerback takes the first receiver who runs into the flat and, if nobody does, works to rob the #1 receiver underneath. The safety over him protects the deep third on that side, the deep safety plays the middle third, and the other cornerback plays the third on the opposite side.

More detail

Cloud gives a defense a way to take away quick throws to the flat and to muddy the quarterback’s reads. It is rarely used as a base coverage, but it is a handy tool, for example against offenses that read the defense to choose their routes.

The diagram

1. The cloud cornerback takes the flat.
2. The safety above him plays the deep third.
3. The deep safety and the other cornerback take the other two thirds.