Introducing the Offense
The offense consists of 11 players whose aim is to move the football down the field. This is to either get into their opponents end zone, or to get close enough to attempt a field goal. In most plays, the offense will huddle for instructions before lining up on the right spot on the field.
The quarterback leads the offensive and calls the plays in the huddle.
The quarterback leads his team down the field by running with the ball or handing the ball off. Their aim is to complete a forward pass to an eligible receiver.
The running back (also called a halfback or a tailback) is typically the primary ball carrier. They are the faster of the two backs lined up behind the quarterback in a standard formation. On offensive plays he either runs with the ball or tries to catch a forward pass. Or he remains in the back field to block for the quarterback.
The fullback is usually the larger of the two backs and often blocks for the running back or quarterback. He can also run with the ball or catch a forward pass. Fullbacks typically carry the ball when a strong running style is needed. Or to gain a few yards for a first down or to score a touchdown.
Wide receivers are known for their speed and ability to catch the ball. They line up close to the sidelines and run downfield to catch passes from the quarterback. A standard formation calls for two wide receivers, but some offenses use three or four at a time.
The tight end lines up on the end of the offensive line. They act as an extra blocker on running plays or becomes a receiver in passing plays. A standard formation uses one tight end, though some offenses call for two.
The linemen are the unsung heros of the offense.
The offensive line in anchored by the center, who lines up in the middle. He snaps the football between his legs to the quarterback to start each offensive play. He is responsible for communicating the blocking scheme to his fellow linemen.
Two guards line up on either side of the center and block oncoming defenders on passing plays. Or their aim is to open running lanes for the running back on rushing plays.
Lined up outside the guards, two tackles join in pass protection and run blocking.
Only players who are ‘eligible’ may catch forward passes. This includes the players lined up on the line of scrimmage on either end of the offensive line. So the wide receiver on the left, or tight end on the right.
Also eligible are those lined at least one yard behind the line or in the backfield at the snap. This includes quarterback, running back, full back, or wide receiver on the right.
Once lined up, the offense (so all players) must all remain set for at least one full second.
Introducing the Defense
The defense consists of 11 players who try to keep the offense from advancing down the field and scoring. With players set in three main units.
Offensive tackles and ends line up across from opposite the offensive linemen. Their job is to push their way across the line of scrimmage into the offensive backfield. This is to disrupt or stop a play at or near the line of scrimmage. Their primary responsibilities are to tackle the ball carrier on rushing plays or rush the quarterback.
Three to five yards behind the defensive line is where linebackers position. Their job is to support the linemen. They do this by tackling the ball carrier, dropping into pass coverage or rushing the quarterback.
The secondary consists of defensive backs – cornerbacks and safeties – who try to prevent eligible receivers from catching passes. Cornerbacks usually line up near the line opposite the wide receivers. Safeties are positioned 10-15 yards downfield and are the last line of defense between offense and the end zone. Defensive backs also pursue the ball carrier and sometimes rush the quarterbacks.
Many defences run a 4-3 defense (four defensive linemen, three linebackers and four defensive backs). In this, the pass rush is primarily generated by the down linemen.
Other teams choose a 3-4 defense (three defensive linemen, four linebackers and four defensive backs). In this, the pass rush comes primarily from the linebackers as the defensive linemen occupy multiple offensive linemen.
On plays where an offense uses additional wide receivers, teams may use a nickel package. This replaces a linebacker or lineman with an extra defensive back or a nicklelback.