Stemming is a defensive technique used to create confusion within an offense's blocking scheme.

Defenses typically stem after the offense has broken the huddle and aligned in its formation. The

movement is usually initiated by a command from the Mike Linebacker, using an alert word such

as "Move" to signal the defense to shift from one alignment to another.

When executed properly, stemming can be highly effective against offenses that rely on

offensive line calls and pre-snap blocking adjustments. By changing the defensive front just

before the snap, defenders force offensive linemen to quickly reassess their assignments,

increasing the likelihood of communication errors and missed blocks.