At its most basic, Cover 4 plays as a four deep, three under defense; and at its most aggressive, it plays almost identically to a tight Cover 0. To the average fan, Cover 4 may sound like a passive, prevent-type defense, while to the more nuanced fan, it may seem like an aggressive coverage that can bring 9 defenders into the box. The truth is that it is all those things and more. One of the greatest powers of the Cover 4 is its ability to adjust, the intricacies, and tweaks that can be made to the same look to both confuse the offense, and remain fundamentally sound. In this article, we’re going to look at the basic elements of coverage in a Cover 4 defense.