American Football Rules
1. Introduction
2. History
3. Field
4. Ball
5. Kick-offs
6. Downs
7. The Players
7.1 Offense
7.2 Defense
7.3 Special Teams
8. The Plays
9. Penalties
9.1 Umpire’s Signals
10. Coach’s Challenge
11. Game Duration
12. Change in Possession
13. Scoring
14. Sources
American Football is similar in many ways to both codes of rugby (and in fact was developed as an offshoot of rugby). It is probably more like rugby league in that each team only gets a limited amount of chances to advance the ball forward at which point they must handover possession. In Rugby League this happens after six tackles are completed, whereas in American Football it occurs when the attacking team fail to advance the ball forward by ten yards over a series of four plays (excluding penalties as will be explained shortly). In Rugby Union, on the other hand, the attacking team can go through as many phases of possession as they wish (as long as they do not commit an offence).
Both American football and soccer have their origins in varieties of football played in the United Kingdom in the mid-19th century, and American football is directly descended from rugby football. McGill University athletes, who had learned rugby from the local British Army garrison, introduced the sport to the U.S. with a game against Harvard University in 1874. The game quickly spread to other Ivy League colleges.
Encouraged by Yale University's Walter Camp, the schools began to adopt rules that would differentiate American football from rugby in the 1880s. The scrimmage was introduced in 1880 and the system of downs in 1882. By the turn of the 20th century, football had become notoriously dangerous; 18 college players died in 1905 alone. Colleges responded with a series of rule changes to open up the game, most importantly the forward pass, along with outlawing dangerous formations such as the "flying wedge", and introducing and requiring better equipment such as helmets.
The game had achieved its modern form by 1912, when the field was changed to its current size, the value of a touchdown increased to 6 points, and a fourth down added to each possession. Originally dominated by the Ivy League, football soon captured the interest of colleges nationwide. By 1916, when the Rose Bowl game matching eastern and western teams became an annual event, football had developed a national following second only to baseball among team sports. Professional football developed in the mill towns of Pennsylvania and the American Midwest in the early years of the 20th century. The NFL was founded in 1920 in Canton, Ohio.
Professional football remained a largely regional sport of secondary importance until after World War II. Television broadcasts greatly enhanced NFL football's national appeal, and the pro game surpassed both college football and baseball in popularity in the 1960s. The first Super Bowl—between the champions of the NFL and the rival American Football League—was played in 1967, and the two leagues merged in 1970.
American football is played on a rectangular field 120 yards (110 meters) long by 53 1/3 yards (49 meters) wide. The longer boundary lines are sidelines, while the shorter boundary lines are end lines. Near each end of the field is a goal line; they are 100 yards apart. A scoring area called an end zone extends 10 yards beyond each goal line to each end line. Yard lines cross the field every 5 yards, and are numbered from each goal line to the 50-yard line, or midfield (similar to a typical rugby league field).
Two rows of lines, known as inbounds lines or hash marks, parallel the side lines near the middle of the field. All plays start with the ball on or between the hash marks. At the back of each end zone are two goal posts (also called uprights) that are 18.5 feet (5.6 m) apart. The posts are connected by a crossbar 10 feet (3 m) from the ground. Teams try to get the ball past the opponent's goal line into the end zone to score a touchdown. At far edge of each end zone are the goal posts which, together with the cross bar, look like a big H. These are used only when a team decides to kick a field goal instead of going for a touchdown or to kick for an extra point (point after touchdown [PAT]) after scoring a touchdown. In the other direction, the field is divided into three parts, left, centre and right, by the hash marks, which are 60 feet from each side line.
Normally, for each play, the ball starts where it ended up at the end of the previous play. However, if the ball ends up outside of the centre part of the field, it is brought back to the nearest hash marks so plays never start at the extreme sides of the field. The area to either side of the field is out-of-bounds.
An American Football is similar to a rugby ball (but more pointed) with the addition a large set of stitches along one side to aid grip.
At the start of the game there is a coin toss to see which team gets the ball first. The team that has the ball is the offense; the other team is the defense. A football game is supposedly one hour, but takes about three hours to play because the clock is often stopped for various reasons. The game is divided into 15 minute quarters with a major division at 30 minutes which is called half time. At the end of the first and third quarters, the players merely switch sides. The ball is moved to the corresponding point on the other side of the field, and play continues. This switching of sides evens up any advantage due to the sun or wind. The players leave the field for 20 minutes at half-time. After half-time, play does not continue where it ended. Instead, the team that originally lost the coin toss gets to have the ball first following another kickoff. At the start of each half and after each touchdown or field goal (when it's time to let the other team have the ball), the defending team starts by placing the ball on a tee at their 35 yard line and kicking the ball toward the other team. This is a kickoff. The other team tries to catch the ball and run it back as far as possible. If the player catching the ball sees there is no hope of running it back, he raises his hand asking for a fair catch. In a fair catch, the defending team may not tackle him and he may not run with the ball. If the ball is kicked into the end zone and no one catches it or the player catching it does not run with it, there is a touchback and the first play starts at the offense's 20 yard line. Unlike a touchdown, a touchback does not score any points.
The offense has 4 plays or downs to cover 10 yards or more. A play ends when the player with the ball is either stopped or goes out-of-bounds or if the ball is thrown and missed (which is called an incomplete pass). A player is stopped when his knees touch the ground either because he was tackled by a defensive player or because he fell. When a play is over an official blows a whistle. Normally, teams try to cover the 10 yards in 3 plays or less. If they don't make it in 3 plays, they use the 4th down to kick the ball toward the other team. The ball is not placed on the ground and kicked as it is in a kickoff. Instead, the ball is snapped back to the kicker who kicks the ball. This is punting. Teams don't have to punt on 4th down. Sometimes, if the distance to complete the 10 yards is very short or if a team is far behind in the score, they elect to go for it on 4th down--to try to complete the 10 yards with another play. If they fail to make it on 4th down, the ball is turned over on downs where it ends up. On 4th down, if they are close enough to the defense's goal posts, the offense may also elect to kick a field goal. If the field goal misses, the ball is turned over to the other team where it was before the field goal attempt. If a team succeeds in advancing 10 yards or more, they get a first down. That is, they get a new set of 4 downs to make another 10 yards.
Each team has 11 players on the field. Before a play starts, the offensive players meet in a huddle to decide which play to use. Plays are normally selected by the coaching staff who radio their selection to the quarter back who then tells the other players. The defensive players might also huddle to select their own strategy for the next play. The players then come up to the line of scrimmage which is an imaginary line drawn from one side of the field to the other through the tip of the football closest to the defense. Each team must stay on their own side of the line of scrimmage until the play starts. However, teams may substitute for any or all of their players, if time allows, during the break between plays. As a result, players have very specialized roles, and almost all of the 46 active players on an NFL team will play in any given game. Thus, teams are divided into three separate units: the offense, the defense and the special teams.
• The offensive line consists of five players whose job is to protect the passer and clear the way for runners by blocking members of the defense. Except for the center, offensive linemen generally do not handle the ball.
• The quarterback (QB) receives the ball on most plays. He then hands or tosses it to a running back, throws it to a receiver or runs with it himself.
• Running backs line up behind or beside the QB and specialize in rushing with the ball. They also block, catch passes and, on rare occasions, pass the ball to others.
• Wide receivers line up near the sidelines. They specialize in catching passes.
• Tight ends line up outside the offensive line. They can either play like wide receivers (try to catch passes) or like offensive linemen (protect the QB or create spaces for runners). Not all of these types of players will be in on every offensive play. Teams can vary the number of wide receivers, tight ends and running backs on the field at one time.
• The defensive line consists of three to six players who line up immediately across from the offensive line. They try to tackle the running backs before they can gain yardage or the quarterback before he can throw a pass
• At least three players line up as defensive backs (some of these are known as safeties). They cover the receivers and try to stop pass completions. They occasionally rush the quarterback.
• The other players on the defense are known as linebackers. They line up between the defensive line and defensive backs and may either rush the quarterback or cover potential receivers.
The units of players who handle kicking plays are known as "special teams". Two important special-teams players are the "punter", who handles punts, and the "placekicker" or "kicker", who kicks off and attempts field goals and extra points.
The offensive linemen all put a hand on the ground except for the centre who puts both hands on the ball. The quarter back stands behind the centre with his hands between the centre’s legs. The quarterback calls out a series of signals. Only the offensive players know which signal starts the play; the defense has to wait to see the play start before they can react. Once the secret signal is given, the play starts when the centre snaps the ball to the quarterback.
The offense has a maximum of 25 seconds from the end of the previous play to start the next play unless a time-out has been called. In a pass play the quarterback takes a few steps back, waits for someone to get open, and throws the ball to that person. That pass receiver can be any offensive player other than a lineman. During a pass play, the defensive front four rush the quarterback hoping to either make him throw the ball early or perhaps even sack him by tackling him before he throws the ball. The offensive linemen try to prevent this by blocking the defensive linemen. However, the offensive linemen are not allowed to use their hands while blocking.
Meantime the defensive backs cover the receivers (try to stop the receivers from catching the ball) by either running with them in man-to-man coverage or by covering any receivers in their part of the field in zone coverage. Sometimes the defensive team blitzes by sending one or more defensive backs after the quarter back. That can be dangerous because it can leave a receiver open--but that won't matter if they can sack the quarterback.
If the pass is not caught before it touches the ground, it is an incomplete pass and the ball returns to the original line of scrimmage. If a pass is picked off (caught) by a defensive player, it is an interception and the ball is turned over to the other team. In a rushing play the quarterback hands the ball off to the tailback or, sometimes, the fullback and that person runs with the ball. The offensive linemen try to open holes in the defensive line for the rusher to run through by blocking the defensive linemen. If the rusher fumbles by losing the ball before the play is over, there is a mad scramble while everyone tries to pounce on the ball.
If a defensive player recovers the fumble, the ball is turned over to the other team. Since 1976 there has been a 30-second clock for all games, visible to both players and fans to note the official time between the ready-for-play signal and snap of the ball. If the ball is not snapped within the 30 seconds then the offensive team are charged with a “delay of game” penalty (5-yard penalty).
The people in the striped shirts are the officials. They carry out various tasks such as raising their arms to signal a touchdown or field goal, deciding if a pass was caught in bounds or out-of-bounds, placing the ball on the line of scrimmage for the next play, measuring to see if 10 yards have been covered, and assessing penalties for rule infractions. To call a penalty, an official takes a piece of yellow cloth, called a penalty marker or flag, from his pocket and throws it on the ground. There is then a flag on the play. There are seven officials in each game:
Referee: The head of the team, he is the one you see on TV, he is in control of the game, gives signals and is the final authority. He lines up behind the offense 10-12 yards, watches the snap, motion, blocks and passes. He also sets final position of the ball at the end of the play. He is usually distinguished from the rest of the officiating team by wearing a white cap.
Umpire: Lines up 4-5 yards behind the defensive line, watches blocking, players equipment, player conduct and actions at the line of scrimmage.
Head Linesman: Lines up outside the offensive formation at the line of scrimmage (to the quarterback's right side) watches for off-sides, encroachment, etc. He rules on out of bounds on his side of the field. Helps the Referee with the final spot of the ball and rules on pass completions.
Line Judge: Lines up outside the offensive formation at the line of scrimmage (to the quarterback's left side) watches for off-sides, encroachment, etc. He rules on out of bounds on his side of the field. He watches anything that happens on the Umpire's blind side.
Back Judge: Lines up 17 yards downfield of the Line Judge. He watches the receivers on his side of the field, makes rulings on down field blocks, catches, illegal touching, interceptions, pass interference and down field loose balls.
Side Judge: Lines up 17 yards downfield of the Head Linesman. He watches the receivers on his side of the field, makes rulings on down field blocks, catches, illegal touching, interceptions, pass interference and down field loose balls.
Field Judge: Lines up 25 yards downfield (in the centre of the field). He watches the tight end, runs the play clock, makes rulings on down field blocks, catches, illegal touching, interceptions, pass interference and down field loose balls.
The main penalties that can be called are detailed below:
Illegal procedure: An offensive linemen moved before the play started or a receiver who was in motion before the play started did not move parallel with the line of scrimmage. Or the quarterback was past the line of scrimmage when he threw a pass. 5 yard penalty.
Ineligible Receiver Down-field: An offensive lineman was too far advanced past the line of scrimmage when the quarterback threw a pass. 5 yard penalty.
Delay of Game: The offensive team took more than 25 seconds to start the play. 5 yard penalty.
Grounding the Ball: The quarter back threw the ball away instead toward a possible receiver because he was about to be sacked. 5 yards and loss of down.
Off-sides: A defensive player moved across the line of scrimmage and either made contact with an offensive player or failed to get back before the play started. 5 yard penalty.
Holding: An offensive lineman used his hands while blocking. 10 yard penalty.
Clipping, Illegal Block, Chop Block: Blocking a player from the back. This can hurt a player because he doesn't know the hit is coming. 10 yards.
Pass Interference: Grabbing or tackling the pass receiver while the pass is in the air. The defender must wait until the ball arrives. However, the defender can try the catch the ball himself, so he may collide with the receiver as they both try to make the catch. If there is interference, the penalty is 15 yards (or to the point of interference if that's less) and a first down is granted even if the ten yards has not been made.
Unnecessary Roughness, Roughing the Passer, Roughing the Kicker: Tackling someone after he no longer has the ball or after the play is over. 15 yards.
Facemask: Grabbing the front of a player's helmet during a tackle. 15 yards if flagrant; 5 yards if incidental.
Helmet to Helmet tackle: The severity of the penalty will vary depending on the severity of the tackle but will usually be 15 yards.
Unsportsman-like conduct: 15 yards. This includes some odd offenses such as group- choreographed celebrations or celebrations that may incite the crowd. After a penalty is called, the other team can accept or decline the penalty. When a penalty is assessed, the ball is brought back to the original line of scrimmage and the penalty is marched off from there. The down is then repeated unless the penalty includes loss of down. That is, the play with the penalty does not count as one of the four allowed to get 10 yards. Thus, if the team with the penalty did poorly on the play, the other team may want to turn down the penalty and accept the play as it was. If both teams get a penalty on the same play, the play is repeated from the original line of scrimmage (the penalties are offset).
The various signals used by the umpires are shown below:
The coach of a team can challenge a call by one of the umpires. This is done by throwing a challenge flag (red flag) onto the field of play before the next play starts. The play is then reviewed and if there is sufficient evidence to show that the call was wrong then it is overturned. Otherwise the call on the field stands. If a challenge is unsuccessful then the challenging team are charged with a time-out. Coaches are not allowed to challenge calls during overtime or in the last two minutes or each half. This is to stop coaches challenging minor calls that may be upheld in order to get a free time out. During these periods an official will decide whether calls should be reviewed. Then they are reviewed in the normal way.
A standard football game consists of four 15-minute (typically 12 minutes in high school football) quarters, with a half-time intermission after the second quarter. The clock stops after certain plays; therefore, a game can last considerably longer (often more than three hours in real time). The last two minutes of a half can take a long time to play. Throughout the game, the clock is stopped whenever there is an incomplete pass or the player with the ball runs out-of-bounds.
The clock is stopped temporarily when there's a first down so the officials can move the chains at the side of the field that are used to measure the 10 yards. And each team has 3 time-outs they can call per half to stop play for a couple of minutes. In the last 2 minutes, the offense uses incomplete passes and running out-of-bounds just to stop the clock. If an NFL game is tied after four quarters, the teams play an additional period lasting up to 15 minutes. In an NFL overtime game, the first team that scores wins, even if the other team does not get a possession—this is referred to as sudden death. In a regular-season NFL game, if neither team scores in overtime, the game is a tie.
In an NFL playoff game, additional overtime periods are played, as needed, to determine a winner. In the second and fourth quarters play continues where is left of in the first and third quarters respectively, whereas the second half is started with a kick-off. Thus, the attacking team usually displays less urgency near the end of the first and third quarters as they will maintain possession for the next quarter.
The offense maintains possession of the ball unless one of the following things happens:
• The team fails to get a first down— i.e., they fail to move the ball forward at least 10 yards in four downs. The defensive team takes over the ball at the spot where the play ends. A change of possession in this manner is commonly called a turnover on downs .
• The offense scores a touchdown or field goal. The team that scored then kicks off the ball to the other team.
• The offense punts the ball to the defense. A punt is a kick in which a player drops the ball and kicks it before it hits the ground. Punts are nearly always made on fourth down, when the offensive team does not want to risk giving up the ball to the other team at its current spot on the field (through a failed attempt to make a first down) and feels it is too far from the other team's goal posts to attempt a field goal.
• A defensive player catches a forward pass. This is called an interception , and the player who makes the interception can run with the ball until he is tackled or forced out of bounds. After the intercepting player is tackled or forced out of bounds, his team's offensive unit returns to the field and takes over at his last position.
• An offensive player drops the ball (a fumble ) and a defensive player picks it up. As with interceptions, a player recovering a fumble can run with the ball until tackled or forced out of bounds. Lost fumbles and interceptions are together known as turnovers .
• The offensive team misses a field goal attempt. The defensive team gets the ball at the spot where the previous play began (or, in the NFL, at the spot of the kick). If the unsuccessful kick was attempted from within 20 yards of the end zone, the other team gets the ball at its own 20-yard line (that is, 20 yards from the end zone).
• An offensive ball-carrier is tackled, forced out of bounds, loses the ball out of bounds, or commits certain penalties in his own end zone. This rare occurrence is called a safety .
A team scores points by the following plays:
• A touchdown (TD ) is worth 6 points. It is scored when a player runs the ball into or catches a pass in his opponent's end zone. A touchdown is analogous to a try in rugby with the major difference being that a try requires the player to place the ball on the ground. However, the player doesn’t actually have to enter the end zone. A TD can be scored if the ball enters the end zone (“breaks the plane”) whilst he in still in play. o After a touchdown, the scoring team attempts a conversion (which is also analogous to the conversion in rugby). The ball is placed at the other team's 3-yard line (the 2-yard line in the NFL). The team can attempt to kick it over the crossbar and through the goal posts in the manner of a field goal for 1 point (an extra point or point after touchdown (PAT) ), or run or pass it into the end zone in the manner of a touchdown for 2 points (a two-point conversion ).
• A field goal (FG) is worth 3 points, and it is scored by kicking the ball over the crossbar and through the goal posts. Field goals may be placekicked (kicked when the ball is held vertically against the ground by a teammate) or drop-kicked (extremely uncommon in the modern game). A field goal is usually attempted on fourth down instead of a punt when the ball is close to the opponent's goal line, or, when there is little or no time left to otherwise score.
• A safety is worth 2 points. A safety is scored by the defense when the offensive player in possession of the ball is forced back into his own end zone and is tackled there, fumbles the ball out of the end zone, or commits intentional grounding in the end zone. Certain penalties (primarily blocking fouls) by the offense occurring in the end zone also result in a safety.
