7–2–2 defense

The 7–2–2 defense or seven-box defense, used seven "down linemen", or players on the line of scrimmage at the time of the snap, two linebackers, and two safeties.Amos Alonzo Stagg invented the seven-box defense in 1890 at Springfield College. At that time, most teams were using a nine-man line on defense, and there were only three downs and no forward passes. The 7–2–2 was the base defense used by Knute Rockne at Notre Dame, as well as Mike Donahue at Auburn. Into the late 1930s, the 7–2–2 was still commonly employed inside the defender's thirty-yard line. It was considered "very strong against a running attack, but rather weak defensively against passes." The 7–2–2 was also employed when the opponent was expected to punt.

The 1906 football rule reforms mandated that offenses use at least seven down linemen. These players usually stood shoulder-to-shoulder before the snap, a posture defenses tended to match. The defenses of the time are considered unsophisticated by today's standards. The interior defensive linemen were expected to hold their ground against their assigned blockers, while the responsibility of disrupting the offense rested primarily with the tackles and ends, especially those lined up on the "strong" side of the opposing line.

Over time, however, as new offensive formations, such as the single wing, were introduced, and increased the lateral running and passing threats, the seven man front changed in character. Box and letter drawings of the seven man front, by coaches such as Bernie Bierman and Steve Owen show a broadly spread front, with the center and two guards versus the interior five offensive linemen, defensive tackles 2–5 yards from the guards, and ends 2–5 yards outside the defensive tackles, and well outside the offensive ends.

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