A strategy used by defensive ends and linebackers to prevent mobile quarterbacks from leaving the pocket.
There are numerous strategies employed by defenses to prevent mobile quarterbacks from hurting the opposing team with his legs, but they all have one thing in common: forcing the quarterback to remain in the pocket to either attempt a pass or take a sack. Contain strategies are typically used against mobile quarterbacks who often have the ability to extend a play with their legs.
The most commonly used strategy is for an outside or middle linebacker to “spy” the quarterback at the beginning of an offensive play. The linebacker is assigned to watch the quarterback and to follow him laterally if he begins to leave the pocket or rollout, thus trapping him in the backfield and forcing him to make a decision with the ball. This linebacker remains behind the defensive line and can drop back into coverage or pursue the quarterback depending on how the play develops. Defensive ends and tackles usually cooperate with linebackers by avoiding too deep a pass rush and helping to force the quarterback wide towards the sidelines if he manages to break containment in the pocket.