The 3-4 defense is a basic football defensive formation that is used by several NFL teams. The alignment features three down linemen and four linebackers in the front seven, thus the name 3-4 defense.

How a 3-4 Defense is Arranged

In a 3-4 defense, the front row of three defense linemen includes a center nose tackle (NT) and two defensive ends (DE), one on either side.

The second rank includes four linebackers (LB). They might at times move up to the line of scrimmage as needed.

Two cornerbacks (CB), one on each side of the field, line up to cover the wide receivers. There are also two safeties. The exact positioning of the defensive backs (cornerbacks and safeties) depends on the type of pass coverage they are in for the play.

Playing the 3-4 Defense

The front line for this defense is typically very large, usually larger than the same positions when used in a 4-3 configuration. The nose tackle in the 3-4 configuration has one of the most challenging positions in the NFL. He faces the offense's center and must control the gaps between the center and his guards, making the tackle for any rush through those gaps.

The defensive ends are also larger than those used in a 4-3 defense. The face off with the offensive guards who are on either side of the center.

The linebackers in the 3-4 defense are the second layer of the defense. Two outside linebackers (OLB) are on either side of the while two inside linebackers (ILB )are between them but behind the front three line. The outside linebackers may be used close to the line of scrimmage while the inside linebackers are further from it. The linebackers respond to the play to make tackles and break up passing plays.

The secondaries in a 3–4 defense are four defensive backs. Two of these are safeties, and two of them are cornerbacks. The cornerbacks line up three to five yards off the line of scrimmage and may play zone defense or man-to-man coverage. The free safety responds to the plays and covers deep passes. The strong safety usually covers closer to the line of scrimmage.

Front Variations

Teams use variations of the 3-4 Defense. These include the 3-4 Okie Front, the 3-4 Eagle Front, and the 3-4 Under Front.

History of the 3-4 Defense

Bud Wilkenson devised the alignment at the University of Oklahoma in the late 1940s. Chuck Fairbanks brought the 3-4 defense to the NFL after he learned it from Wilkinson. It became a very popular defense alignment in the late 1970s through early 1980s and was used by the Miami Dolphins in their Super Bowl win and undefeated season in 1972. In Super Bowl XV in 1981, both teams used the 3-4 defense.

However, its popularity declined and by 2001 only one NFL team was using it. Then a resurgence started, perhaps due to the success of that team, the Pittsburgh Steelers, and by 2016 there were 16 NFL teams using the 3-4 defense.