Introduction

We've already learned about scrimmage downs and the concept of the down cycle. Now, it's time to learn how a scrimmage down works.

All scrimmage downs have two phases:

1. The ball is 'live'
2. 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'

The scrimmage down ends when the ball is declared 'dead' by officials. So when does this happen? The ball is 'dead' when one of the following occurs on a scrimmage down:

• 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.

Chain Crew

At the end of every scrimmage down, a group of referees known known as the chain crew will mark the locations of the line of scrimmage and the 1st down line.