3–3–5 defense

In American football, the 3–3–5 defense is a defensive alignment consisting of three down linemen, three linebackers, and five defensive backs. The 3–3–5 defense can also be referred to as the 3-3 stack and the Spread Defense. It is one form of the nickel defense, a generic term for a formation with five defensive backs. Veteran college football defensive coordinator Joe Lee Dunn is widely credited with being the main innovator of the 3-3-5 scheme.

This alignment is generally used when the defense is trying to confuse the offense by applying different blitz pressures on the offense while playing mostly zone or sometimes man coverage. This alignment is rarely seen in the NFL, but is used by many high schools to counterattack the spread offense scheme. Boise State, West Virginia, BYU, and Arizona have used this formation with success in college football. Michigan ran this formation during the 2010 season. TCU uses this as a variant formation; its base defense is a different nickel set, the 4–2–5.

Teams that run the 3-3-5 generally use it because they are a relatively fast but smaller unit compared to the opposing offense, and they want to cause blocking assignment issues for that offense. Also, a 3-3-5 can be adjusted to a 4-3, 3-4, or 4-4 defense with the same starting players.

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