The purpose of this page is to illustrate the various defensive formations that are seen on the field. There are many different variations of these defenses, but these variations all come from the same BASIC formations, as shown below.
Typically, the first digit in the defensive name refers to the number of down linemen. The second number represents the number of linebackers. A nickel defense includes 5 defensive backs. A dime defense has 6 defensive backs.