scrimmage: offense![click to hear](/images/speaker.jpg)
The offense or team with ball possession has four downs to gain 10 yards. If it succeeds, it is given another four downs; if not, the ball is turned over to the other team by means of a punt.
right tackle ![click to hear](/images/speaker.jpg)
Position on the outside of the right guard; this player blocks the opposing defense and protects the quarterback in passing situations.
right guard ![click to hear](/images/speaker.jpg)
Position to the right of the center; this player has a blocking role in passing and running situations.
center ![click to hear](/images/speaker.jpg)
Position at the center of the offensive line; this player puts the ball in play by snapping it to the quarterback.
left tackle ![click to hear](/images/speaker.jpg)
Position on the outside of the left guard; this player blocks the opposing defense and especially protects the quarterback in passing situations.
left guard ![click to hear](/images/speaker.jpg)
Position to the left of the center; this player has a blocking role on passing and running plays.
quarterback ![click to hear](/images/speaker.jpg)
Position behind the center; the offensive leader, this player gathers teammates together between downs and communicates tactics.
fullback ![click to hear](/images/speaker.jpg)
Position behind the quarterback; this player protects the quarterback in passing situations and blocks for the tailback.
tailback ![click to hear](/images/speaker.jpg)
Position behind the fullback; this fast player often carries the ball (running play).
tight end ![click to hear](/images/speaker.jpg)
Position on the outside of the tackle; this versatile player blocks opposing players and catches passes.
wide receiver ![click to hear](/images/speaker.jpg)
Two positions at the far end of the offensive line; they use speed and agility to separate themselves from the defense and catch passes.
line of scrimmage ![click to hear](/images/speaker.jpg)
Imaginary line along which the offense and defense face one another before the ball is snapped.