Sack
Downs
Interception
Fumble
Line of Scrimmage
The offensive team has 4 to advance the ball to the next 1st down marker. Teams may advance the ball by passing or rushing.
When the defensive player catches a pass intended for an offensive receiver
When the Quarterback has his flag pulled by the defense behind the line of scrimmage
When the ball is dropped after being in possession
The imaginary line where the nose of the ball is placed to separate the offensive team from the defensive team.
