All scrimmage downs have two phases:
- The ball is 'live'
- The ball is 'dead'
The Ball Is 'Live'
The scrimmage down begins when the ball is declared 'live' by officials. So when does this happen? Every scrimmage down begins with a snap, also known as a hike. A snap or hike is a backwards pass through the legs of the center to the quarterback. These are both players in the offensive unit.
The Ball Is 'Dead'
- a score is made
- a pass is incomplete
- the ball carrier is tackled to the ground
- the ball is carried or thrown out-of-bounds
See all the ways a ball is declared 'dead' by officials here.