Like HowStuffWorks on Facebook!

How American Football Works


Moving the Football and Finding the End Zone

A football game begins with a coin toss to decide which team will receive the opening kickoff. From the opening kickoff, the two teams battle to take possession of the ball. Possession means that a team's offensive unit has the ball.

A team can take possession of the ball in several ways:

  • Receiving a kickoff - A team receives a kickoff at the beginning of each half and after the other team scores.
  • Turnover - A team recovers a ball dropped by the other team (fumble) or picks off a ball thrown by the other team's quarterback (interception).
  • Safety - A player is tackled in his own end zone, meaning the end zone his team is defending, so the other team gets the ball though a free kick.
  • Punt - The defensive team stops the offensive team from getting 10 yards in three downs, and the offensive team free-kicks, or punts, the ball to the other team on third down.
  • Turnover on downs - The offensive team fails to advance the ball 10 yards in four downs and has to surrender the ball to the other team.

For those new to the sport, the last two scenarios on this list may not make sense. One of the most confusing concepts of American-style football is the down-and-distance system. Every time a team takes possession of the ball, it is given a set of four downs, or attempts, to move the ball 10 yards. If the team can move the ball 10 yards or more within four downs, the team gets another set of four downs to go another 10 yards, and so on. For instance, if a team advances 3 yards on first down, the next play is second down with 7 yards to go (second and 7); if the team then advances 5 yards on second down, the next play is third and 2; if the team then advances 2 or more yards on third down, the next play is back to first and 10, with a whole new set of four downs during which to advance the ball.

After each play, the officials determine how many yards a team has advanced or lost (a team can lose yards if the ball holder is tackled behind the line of scrimmage -- this line is discussed in a moment). The officials then place the ball at the point where the team has ended up. This point determines the line of scrimmage, which is an imaginary line that runs across the field and is the starting point for the offensive team on each play. On the sideline, a team of officials handles a 10-yard-long chain, which designates that 10-yard mark a team must reach to get a first down. On close plays, this chain is sometimes brought onto the field to measure the distance from the ball to the 10-yard mark. The nose of the ball must reach the bar connected to the end of the chain for a team to be awarded a first down.

If a team fails to gain 10 yards after three downs, it may choose to punt the ball to the other team. If it doesn't punt and chooses to use its fourth down, or "go for it," it must reach the 10-yard mark or it surrenders the ball. A team often chooses to punt the ball in order to back the opposing team up so that it has to cover a greater distance to score. The team receiving the punt can return it, meaning it can catch and run it back down the field. The kicking team is hoping to kick the ball down the field and tackle the receiving team's kick returner before he comes back down the field.

All of this pushing and shoving to move a cowhide-covered ball has one purpose: move the ball over the opponent's goal line to score a touchdown.

Philadelphia Eagles running back Duce Staley
Photo courtesy The Philadelphia Eagles
Running the ball

The opponent's goal line is the one a team is advancing toward. Once any part of the ball reaches the edge of the goal line, it is considered in the end zone, and a touchdown has been scored. You will often hear commentators say that a ball breaks the plane of the end zone, which means the ball has crossed over the goal line.

A touchdown is just one way of scoring points in football. After scoring a touchdown, a team can kick a field goal for an extra point or attempt to run or pass the ball into the end zone for a two-point conversion. The team has only one chance at the two-point conversion.

Here is a complete look at ways points are scored and how many points are awarded for each:

MethodDescription
Points
Touchdown (TD)A ball is carried into an opponent's end zone or caught in the end zone.
6 points
Extra pointA ball is kicked through the uprights of the opponent's goalpost after a touchdown.
1 points
2-point conversionA ball is carried into an opponent's end zone or caught in the end zone.
2 points
Field goalA ball is kicked through the uprights of the opponent's goalpost.
3 points
SafetyA player tackles an opposing player in the opposing player's own end zone.
2 points

After scoring a field goal or touchdown and completing the extra point or two-point conversion attempt, a team must kick the ball to the opposing team. The only exception is on a safety. A team that scores a safety gets the ball on a free kick.