The Short Story

A football game is generally played by teams of eleven players (although eight-man football is common in some areas of the country, such as Nebraska, where small towns have difficulty fielding 11-man teams). Players can be substituted on an unlimited basis after the referee's whistle signals the end of a play and before the ball is snapped for the next play.

Offense

In playing the game and trying to get the ball further down the field in order to score, here is some basic information that you need to know:

• The offense, the team that has possession of the ball, has to advance the ball at least 10 yards within the four chances (or downs). If they are successful, they receive four more downs to advance the ball further.
• In trying to advance the ball further down the field, the offense usually hands it off to a runner or throws it to a receiver-both of which is known as "running a play."
• A play officially ends when a player with possession of the ball is tackled to the ground; this uses up one of their four downs.
• If a team only has one more down to advance the ball 10 yards, they usually punt it to the other team. Since the opposing team gets the ball from wherever the ball is lost, punting (kicking) the ball on the fourth down forces the opposing team to start their next offensive series of plays further away from their goal line (unless, of course, the punt returner carries the ball back beyond the place from where the ball was kicked, called the line of scrimmage.

Defense

The team without possession of the ball is on defense. Its goal is to prevent the team with the ball (the offensive team) from gaining 10 yards within the span of four plays in order to gain a first down, and ultimately, to prevent the offensive team from scoring a touchdown (worth six points) or field goal (worth three points).

Defensive players try to stop the offensive player in possession of the ball from gaining the yardage necessary for a first down or breaking the plane of the goal line in order to score a touchdown by:

• tackling the player so that one knee touches the ground;
• knocking the ball out of the player's hands before his knee has touched the ground (causing a fumble);
• preventing the offensive team from completing a forward pass (causing an incompletion); or
• intercepting the ball in the field of play.

Scoring

The team with the most points at the end of regulation play wins the game. There are five different ways to score points in football:

1. Touchdown (6 points): when a player (whether on offense or defense) either runs into the 10 yard end zone of the opposing team in possession of the ball, catches the ball in the opposing team's end zone with at least one foot in bounds (both feet need to be in bounds in the NFL), or recovers a fumble and falls on the ball in the opposing team's end zone, his team is awarded 6 points.
2. Field goal (3 points): The team on offense is awarded 3 points when its kicker (called a place kicker or field goal kicker) boots the ball placed on the ground after it is snapped by the center to the holder and the ball clears the crossbar of the goal post and between the two uprights.
3. Two point conversion (2 points): Immediately after scoring a touchdown, a team is given the option of running an additional play from scrimmage or kicking an extra point. If it elects to try a two point conversion and is successful in running the ball into the end zone, or an eligible receiver catches the ball in the field of play and runs it into the end zone or catches the ball in the end zone, the team is awarded two points.
4. Extra Point after touchdown (1 point): when an offensive player kicks the ball over the crossbar and between the goalpost's two uprights after a touchdown, the offense is awarded one point (P.A.T. or point after touchdown).
5. Safety (2 points): If the defense tackles the offensive player with the ball in the end zone, the defense is awarded two points and possession of the ball after it is kicked by the offensive team (either by way of a punt or kick-off) from its own 20-yard line.

Positions

Now that you understand the basics of the game, we can get into each of the eleven positions that are required for a team. We will start with all of the defensive positions since every team needs a strong defense in order to be successful.

Defense

• Defensive End: There are two defensive ends, one at end of the offensive line. The defensive end's role is to cover the running back on sweeps/end runs to his side or to rush the quarterback in passing situations.
• Defensive Tackle: In a four-man line, defensive tackles line up inside the defensive ends. their job is to tackle running backs running through the middle of the line/off tackle, rush the quarterback dropping back to pass to either tackle him before he has thrown a pass (called "sacking the quarterback"), block his pass attempt, or make him hurry his throw so that he fails to complete a pass to a receiver, or occupy opposing blockers to allow linebackers to make tackles of running backs or the quarterback.
• Nose Tackle: In a three-man line (there is no nose tackle in a four-man line: it is comprised of two ends and two tackles), a nose tackles line ups opposite the opposing team's center and blocks the opposing team's offensive interior linemen (usually the center or one of the guards). His job is basically to neutralize the center or guard blocking him so that the running back has no hole up the middle in which to run. Nose tackles are usually the strongest and biggest defensive players on the field. They don't need to be as fast as other defensive players because their position relies more on strength than speed.
• Linebacker: Linebackers line up between the defensive line and the defensive safeties. There are typically three to four linebackers in a defensive formation and they usually make the majority of the tackles on the team. Linebackers can also drop back in pass coverage (usually covering the tight end) and they can also rush the quarterback ("blitz") to try to sack him or cause him to hurry his pass so it falls incomplete.
  Linebackers usually have a combination of strength, size, and quickness. A good linebacker is a sure tackler and has the ability to "read" the play to see whether it is a run (in which case they move towards the ball carrier to try to make the tackle) or pass (in which case they either rush the quarterback or drop back to cover receivers going downfield).
• Safety: There are usually two safeties in the defensive backfield: a "strong" safety, who generally covers the tight end on pass plays (he is called the strong safety because he lines up on the side of the offensive line with the tight end, or the "strong" side of the line) and helps the defensive line and linebackers stop running plays, and a "free" or "weak" safety, who lines up against the "weak" side of the offensive line (the side without the tight end) and is free to roam the field, assisting the cornerbacks and linebackers in pass coverage and providing the last line of defense on running plays.
• Cornerback: There are usually two cornerbacks, one on each side of the field. Cornerbacks line up opposite the offensive team's wide receivers and cover them on pass players either in man-to-man coverage (covering a single receiver) or zone (staying in a particular area and releasing the wide receiver to coverage by a linebacker or safety when he leaves his zone). On running plays to the outside, the cornerback on that side is responsible for keeping the running back from getting outside of his coverage to run down the sidelines, and turning the play back into the middle so that linebackers and safeties can make the tackle.

Offense:

Offensive Backfield:

• Quarterback: Quarterbacks receive the ball (the "snap") from the center at the beginning of each play, either directly from behind the center (called "under center") or in a "shotgun" formation in which they stand several yards behind the center and receive the ball snapped back to them. Once a quarterback gets the ball he either passes the ball to a receiver, hands it off (the "hand-off") or tosses ("pitches") to a running back, or try to advance the ball by running with it themselves ("quarterback sneak" or "quarterback draw"). They are the leaders of the offensive team and "run" the offense.
• Halfback/Tailback: The halfback is usually the team's best runner. At the high school level, a halfback isn't always a big player, but he is almost always tough, durable, fast and quick. The halfback either takes the hand off or pitch from the quarterback on running plays, stays in to block for the quarterback on pass plays or becomes a pass receiver himself. A tailback is distinguished from a halfback by the fact that a tailback lines up directly behind the fullback (also called the blocking back) in a so-called "I" formation.
• Fullback: Fullbacks either run-block for halfbacks, leading the halfback through the hole in the line to block a linebacker, stay in the backfield to block for the quarterback on pass plays, or take a hand off from the quarterback on running plays, usually straight-ahead running plays and in short yardage situations where their size and strength helps them grind out the yardage needed for a first down or touchdown.

Receivers:

• Wide Receiver: The wide receiver's main role is to catch passes from the quarterback and block the defensive cornerback on outside running plays .
• Tight End: The tight end can be both a receiver and a blocking player.
• Slot Back: The slot back or slot receiver stands a yard or two back from the offensive line (in the "slot") between the wide receiver and the rest of the offensive line. He runs pass patterns, blocks, or is used as a running back on reverses or end-arounds.

Offensive Linemen

• Offensive Tackle: The two tackles line up on the outside of the guards. They are usually the biggest and strongest offensive lineman and are asked to block the biggest and strongest defensive lineman - the defensive tackles - on running plays (especially "off-tackle" runs) and to protect the quarterback from onrushing lineman on pass plays.
• Offensive Guard: The offensive guards line up on either side of the center and block. They are usually quicker, faster and lighter than offensive tackles, and often "pull" out of their position to lead running plays designed to go to the outside ("sweeps").
• Center: The center is responsible for snapping/hiking the ball to the quarterback at the beginning of each play, either when the quarterback is "under center" (i.e. right behind) him, in which case he snaps the ball directly into the quarterback's hands, or via a "direct" snap to the quarterback when he is in a "shotgun" formation and is standing several yards back from the offensive line.

Special Teams

Players who are on the field in special situations are said to play on "special teams."

• Punter: Punters typically come in on fourth down to take a direct snap from the center and kick or punt the ball down field in order to force the opposing team to start their next offensive series of plays further away from their goal line.(Note: there are no punts in games involving the youngest players).
• Punt Returner: Punt returners catch a punted ball and either call for a "fair catch" (in which case the ball, assuming it is caught is placed at the spot of the catch) or receive the ball and run with it towards the opposing team's end zone.
• Kick-off returner: Kick-off returners catch a ball kicked from the opposing team's 40-yard line (30 yard line in the NFL and college)(Note: the rules for kick-offs vary by league and are sometimes modified substantially from those that apply at the high school, college and pro levels)
• Long Snapper: Long snappers play in the center's position and make long, accurate hikes towards the holders (on field goal or extra point attempts) or punters.
• Holder: The holder catches snaps from the long snapper and holds it so that it may be kicked for a field goal or extra point by the place kicker.
• Place-kicker: Place-kickers kick the ball on field goal attempts, kickoffs (at the beginning of each half, after touchdowns or field goals or safeties), or extra point attempts.