Gambling Guide

The ball used in American football has a pointed oval or vesica piscis shape, and usually has a large set of stitches along one side.

American football, known in the United States and Canada ^[1] simply as football, is a competitive team sport. The object of the game is to advance the football towards the opposing team's end zone and score points. The ball can be advanced by carrying the ball, or by throwing or handing it from one teammate to the other. Points can be scored in a variety of ways, including carrying the ball over the goal line, throwing the ball to another player past the goal line or kicking it through the goal posts on the opposing side. The winner is the team with the most points when the time expires and the last play ends.

Outside of the United States and Canada, the sport is usually referred to as American football (or sometimes as gridiron or gridiron football) to differentiate it from other football games, especially association football (soccer) and rugby football. In Japan, it is referred to as "amefuto" (an abbreviation). American football evolved as a separate sport from rugby football in the late 19th century. Arena football is an invented variant of American football. Canadian football, which also descended from rugby, is closely related to the American sport with a few key differences; the word "football" in Canada can mean American football or Canadian football depending on context. Many in both Canada and the northern United States consider American and Canadian football to be two codes of the same game.

Contents 1 Popularity 2 The rules of American football 2.1 Field and players 2.2 Game duration 2.3 Advancing the ball 2.4 Changes of possession 2.5 Scoring 2.6 Kickoffs and free kicks 2.7 Penalties 2.7.1 Some common penalties 3 The players 3.1 Offense 3.2 Defense 3.3 Special teams 4 Basic football strategy 5 Physicality of the game 6 Development of the game 7 Problems in football 8 Leagues, Organizations, and Associations 8.1 United States 8.2 Internationally 8.3 Alternate Rulesets 8.4 Non-current Leagues 9 Misc. Terminology 10 Footnotes 11 References 12 External links

Popularity

Since the 1960s, football has outranked baseball as the most popular spectator sport in the United States ^[2]. The 32-team National Football League (NFL) is the most popular and only major professional American football league. Its championship game, the Super Bowl, is watched by nearly half of U.S. television households, and is also televised in over 150 other countries. Super Bowl Sunday has become an annual ritual in late January or early February. Football is also the most watched sport on television in the United States.

The NFL also operates a developmental league, NFL Europe, with teams in five German cities, and one in the Netherlands.

A Colorado State University player runs with the ball as an Air Force Academy player lines up a tackle.

College football is also extremely popular throughout North America. Several college football stadiums seat more than 100,000 fans — which regularly sell out. Even high school football games can attract five-figure crowds, especially in football hotbeds like Alabama, Western Pennsylvania, Nebraska, Ohio, Georgia and Texas. The weekly autumn ritual of college and high-school football — which includes marching bands, cheerleaders and parties (including the ubiquitous tailgate party) — is an important part of the culture in much of smalltown America. It is a long-standing tradition in the United States (though not universally observed) that high school football games are played on Friday, college games on Saturday, and professional games on Sunday (with an additional professional game on Monday nights).

Certain fall and winter holidays — most notably Thanksgiving, Christmas, and New Years' Day — have traditional football games associated with them.

Football is also played recreationally by amateur club and youth teams (e.g., the Pop Warner little-league programs). There are also many "semi-pro" teams in leagues where the players are paid to play, but at a small enough salary that they generally must also hold a full-time job.

Pro football is played in the United States and in the above-mentioned NFL Europe league. The professional Canadian Football League plays under Canadian rules. The sport is popular as an amateur activity in Mexico and American Samoa and to a lesser extent in Japan, Europe and Australia.

Organized football is played almost exclusively by men and boys, although a few amateur and semi-professional women's leagues have begun play in recent years.

The rules of American football

The object of American football is to score more points than the opposing team within a set time limit.

Field and players

The numbers on the field indicate the number of yards to the nearest end zone.

American football is played on a rectangular field 120 yards (110 metres) long by 53 1/3 yards (49 metres) 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 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 apart(24 feet in high school). The posts are connected by a crossbar 10 feet from the ground. Successful kicks must go above the crossbar and between the uprights. (At professional, college, and some high school fields, the uprights and crossbar are attached by a curved bar to a padded post outside the field of play, to reduce the chance of players running into the supports. Many high schools, though, use an H-shaped structure located behind the endlines, allowing the structure to be used as a soccer goal as well.)

Each team has 11 players on the field at a time. 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 53 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 (see below). In the NFL, players' jersey numbers are distributed according to a strict system (e.g. quarterbacks always wear between 1-19).

Game duration

A standard football game consists of four 15-minute (typically 12 minutes in high school football) periods (called quarters), with an intermission (called halftime) 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). 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, ending the game. In a regular-season game, if neither team scores, the game is a tie. In a post-season game, play continues with additional overtime periods until the tie is broken, as in the 1971 Christmas Day double-overtime game between the Miami Dolphins and Kansas City Chiefs, the longest game in NFL history. College overtime rules are more complicated and are described at Overtime (sport).

Advancing the ball

Advancing the ball in American football resembles the six-tackle rule and the play-the-ball in rugby league football. The team that takes possession of the ball (the offense) has four attempts, called downs, to advance the ball 10 yards towards their opponent's (the defense's) end zone. When the offense gains 10 yards, it gets a first down, or another set of four downs to gain 10 yards. If the offense fails to gain a first down (10 yards) after 4 downs, it loses possession of the ball.

Except at the beginning of halves and after scores (see Kickoffs and free kicks below), the ball is always put into play by a snap. All players line up facing each other at the line of scrimmage (the position on the field where the play begins). One offensive player, the center, then passes (or "snaps") the ball between his legs to a teammate, usually the quarterback.

Players can then advance the ball in two ways:

• By running with the ball, also known as rushing. One ball-carrier can hand the ball to another; this is known as a handoff.
• By throwing the ball to a teammate, known as a forward pass or as passing the football. The forward pass is a key factor distinguishing American and Canadian football from other football sports. The offense can throw the ball forward only once on a play and only from behind the line of scrimmage. The ball can be thrown sideways or backwards at any time. This type of pass is known as a lateral and is much rarer in American football than in rugby league or rugby union, where a backwards pass is mandatory.

A play (also called a down) ends, and the ball becomes dead, after any of the following:

• The player with the ball is forced to the ground or has his forward progress halted by members of the other team (as determined by an official).
• A forward pass flies out of bounds or touches the ground before it is caught. This is known as an incomplete pass. The ball is returned to the original line of scrimmage for the next down.
• The ball or the player with the ball goes beyond the dimensions of the field (out of bounds).
• A team scores.

Officials blow a whistle to notify all players that the play is over.

At all times, players and fans must be aware of the sequence of downs and the distance to a new first down. When a team has a first down, the scoreboard or television screen flashes "1st and 10" — that is, first down and 10 yards to go. If the team gains three yards on the first play, for example, the next down will be "2nd and 7." If the team gains 6.5 yards on the next play the scoreboard may say "3rd and inches." If a team gains a first down within the ten yard line then the scoreboard or television reads "(the down) and goal."

Changes of possession

The offense maintains possession of the ball unless one of the following things happens:

• The team fails to get a first down, that is, 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. (See Scoring and Kickoffs below.)
• 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 to his receiver. This is called an interception, and the player who makes the interception can run with the ball until tackled, forced out of bounds, or scores. 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 ballcarrier 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. (See Scoring below.)

Scoring

A team scores points by the following plays:

• A touchdown (TD) is worth 6 points. A touchdown is scored when a player runs the ball into or catches a pass in his opponent's end zone.
  • After a touchdown, the scoring team attempts a conversion. 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). In collegiate and professional leagues, the extra point is usually preferred; its success rate is 94% in the NFL and 93.8% in the NCAA, compared to 43% in the NFL and 43.5% in the NCAA for two-point conversions. If the defense forces a turnover on an attempted conversion and runs the ball back to their opponent's endzone, they are awarded with 2 points (does not apply in the NFL).
• 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. A field goal is usually attempted on fourth down instead of a punt when the ball is close to the 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, or fumbles the ball out of the end zone, or commits intentional grounding in the endzone. Certain penalties by the offense occurring in the end zone also result in a safety - these result in two points. This is the only time that a team gains possession of the football immediately after scoring.

Kickoffs and free kicks

Each half begins with a kickoff. Teams also kick off after scoring touchdowns and field goals. The ball is kicked from a kicking tee, which is made from one's own 30-yard line in the NFL and from the 35-yard line in college football. The other team's kick returner tries to catch the ball and advance it as far as possible. Where he is stopped is the point where the offense will begin its drive, or series of offensive plays. If a kick returner does not want to run with the ball, he has the option to signal for a "fair catch" by waving his hands in the air before the catch. He will then be allowed to catch the ball without being tackled. If the kick returner catches the ball in his own end zone, he can either run with the ball, or elect for a touchback by kneeling in the end zone. The receiving team can starts its offensive drive from its own 20-yard line. A touchback also occurs when the kick goes out of the end zone. Punts and turnovers in the end zone can also end in touchbacks.

After safeties, the team that gave up the 2 points puts the ball into play with a punt or placekick from its own 20-yard line.

A halfback leads fellow backs through an agility drill

Penalties

Rule violations are punished with penalties. Most penalties result in moving the football either towards the endzone in the case of a defensive penalty, or away from the endzone in the case of an offensive penalty. Some defensive penalties give the offense an automatic first down. In addition, if a penalty gives the offensive team enough yardage to gain a first down, the first down is automatically given. If a penalty occurs during a play, an official throws a yellow flag near the spot of the foul. When the play is over, the team that did not commit the penalty has the option of taking either the penalty or the result of the play. For example, say a defensive player commits an offsides penalty on first down by passing the line of scrimmage before the snap, and the offense gains eight yards on the play. The team with the ball has the option of taking the penalty and repeat the first down with five yards to go, or declining the penalty and scrimmaging with 2nd and 2.

Some common penalties

• False start: A player on the offense, other than a back moving parallel to the line of scrimmage, moves just prior to the snap. Five yards. Replay of down.
• Offsides: A player is on the wrong side of the ball at the start of a play. Five yards. Replay of down. Similar fouls: Touching an opponent before the snap is encroachment; lining up alongside the football instead of behind it is a neutral zone infraction.
• Holding: A blocker unfairly impedes a would-be tackler or pass receiver, by grabbing the player's jersey, hooking, or tackling. When committed by the offense, or by either team on a change of possession, the penalty is ten yards. When committed by the defense, the penalty is five yards and an automatic first down is awarded to the offense. If the penalty occurred beyond the line of scrimmage, the penalty would be enforced from the spot of the foul.
• Illegal block in the back: A blocker hits a would-be tackler or pass receiver from behind, but above the waist (for the same block below the waist, see "clipping"). Ten yards from the spot of the foul.
• Pass interference: After a pass is launched into the air, a defender pushes, hooks, grabs, or knocks down a would-be pass receiver, or if the receiver does the same to the defender to prevent an interception. First down at the spot of the foul if against the defense (15 yards from the previous spot in college football), or ten yards from the previous spot if against the offense. Similar penalties before a pass are called as holding or illegal contact.
• Facemask: a player places his hand on an opponent's facemask during a play. Five yards if the contact was accidental, or fifteen (a personal foul) if the player hooks his fingers into the facemask or uses the facemask to pull the player to the ground. Also called "minor facemask" and "major facemask."
• Roughing the passer/kicker: A player places a hard hit on a passer long enough after a pass has been thrown to consider the contact avoidable, or places a hard hit on a punter or place kicker. Fifteen yards and automatic first down.
• Running into the kicker: Any contact on a kicker after a kick has been made. Five yards.
• Intentional grounding: The passer throws a forward pass not near any eligible receiver, without first leaving the area behind where the blocking linemen were standing before the snap (the "pocket"), or the passer throws a forward pass outside of the pocket which does not reach the original line of scrimmage and is not near any eligible receiver. Ten yards plus loss of down, except if the penalty occurred in the end zone, then it is ruled a safety, and the defense is awarded 2 points. In college football and high school football, the defense is also credited with a quarterback sack. Note that spiking the ball to stop the clock is exempt from this.
• Ineligible receiver downfield: On every play the offense must have 7 players on the line of scrimmage, the player furthest from the ball on each side are eligible receivers; the interior five players are considered ineligible to receive passes. This penalty is called if one of the 5 interior players is more than five yards past the line of scrimmage during a forward pass.
• Dead ball personal foul: After the play is blown dead, a player tackles or makes rough contact with a player on the other team. Fifteen yards, automatic first down if on defense. May result in an ejection if severe enough.
• Unnecessary roughness: A catch-all for rough play that doesn't merit its own foul. An example is an avoidable late hit on a ball carrier who has run out of bounds. Fifteen yards.
• Unsportsmanlike conduct: Another catch-all call, commonly used for taunting, excessive celebration after a touchdown, and certain banned forms of pantomime (like slashing the throat). Fifteen yards.
• Clipping is a block that occurs from behind - below the waist. Due to the high possibility of injury it is a major penalty. 15 yards. Automatic first down. Possible ejection. At one time, all blocks from behind were considered "clipping," but due to the somewhat lesser risk of injury with blocks above the waist, the "illegal block" penalty was created.
• Spearing is contacting another player with one's head. Also called "helmet to helmet contact." Major penalty. 15 yards. Automatic first down. Possible ejection.
• Delay of game is failure to start the play before the play clock reaches zero. Five yard penalty. Replay of down.
• Illegal procedure Used to indicate a number of infractions, including an illegal snap, having less than seven players on the offense's line of scrimmage, and taking more than two steps after making a fair catch. Five yard penalty. Replay of down.

The players

As noted above, most football players have highly specialized roles. At the college and NFL levels, most play only offense or only defense.

Offense

• 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 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.

Defense

• The defensive line consists of three to five players who line up 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. 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 backs and may either rush the quarterback or cover potential receivers .

Special teams

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. It is rare, but not unheard of, for these two positions to be filled by the same player. The reasoning behind this is because the kicking actions of the punter and placekicker are very different.

Basic football strategy

To some fans, the chief draw of football is the chess game that goes on between the two coaching staffs. Each team has a playbook of dozens to hundreds of plays. The term, play, refers to the coordinated movements and actions that the players should follow on a down. Ideally, it is a scripted strategically sound team coordinated endeavour. Some plays are very safe; they are likely to get only a few yards. Other plays have the potential for long gains but at a greater risk of a loss of yardage or a turnover.

Generally speaking, rushing plays are less risky than passing plays. However, there are relatively safe passing plays and risky running plays. To deceive the other team, some passing plays are designed to resemble running plays and vice versa. There are many trick or gadget plays, such as when a team lines up as if it intends to punt and then tries to run or pass for a first down. Such high-risk plays are a great thrill to the fans when they work. However, they can spell disaster if the opposing team realizes the deception and acts accordingly.

It has been suggested that football is the sport that most closely resembles real war strategically. It is by far the most popular sport in the American military. In fact, the United States Military Academy, the United States Naval Academy, and the United States Air Force Academy each field football teams that participate in Division I-A of the NCAA. Army and Navy have a particularly historic rivalry.

Physicality of the game

American football is a collision sport. To stop the offense from advancing the ball, the defense must tackle the player with the ball by knocking him down. As such, defensive players must use some form of physical contact to bring the ball-carrier to the ground, within certain rules and guidelines. Tacklers cannot kick, punch or trip the runner. They also cannot grab the face mask of the runner's helmet, lead into a tackle with their own helmet, or lift the ball carrier up off his feet and drop him. Despite these and other rules regarding unnecessary roughness, most other forms of tackling are legal. Blockers and defenders trying to evade them also have wide leeway in trying to force their opponents out of the way. Quarterbacks are regularly hit by defenders coming on full speed from outside the quarterback's field of vision.

The high level of physical contact in football makes it more dangerous than other major American team sports. To compensate for this, players must wear a good deal of special protective equipment, such as a padded plastic helmet, shoulder pads, hip pads and knee pads. These protective "paddings" were introduced decades ago and improved ever since to help minimize lasting injury to players. However, increased padding has allowed players to make harder hits; though there are fewer minor injuries in American football than in other codes of football, serious injuries such as spinal cord injuries are much more common.

Despite protective equipment and rule changes to emphasize safety, injuries remain very common in football, due to its physical nature. Twenty-five football players, mostly high schoolers, died from injuries directly related to football from 2000-2004, according to the National Center for Catastrophic Sport Injury Research. Concussions are common, with about 41,000 suffered every year among high school players according to the Brain Injury Association of Arizona. [1]. It is common to see injuries in the game, and deaths are not unheard of. The game is particularly risky when played by amateurs without proper gear, such as is common amongst Americans in backyards and parks across the country.

Some have criticized American football as a violent sport. American football is indeed quite physical in comparison to other major American team sports, such as basketball and baseball. Tackle football is often banned in American schoolyards in favor of touch football, which uses two-hand touching instead of tackling; or flag football in which a player is "tackled" when an opponent pulls a flag off a belt attached to the player's waist. School physical education classes often use the "two-hand touch" version of the game, leaving the tackles to the school's official after-school sports program which can provide the appropriate gear and supervision.

The level of physical aggression and risk of injury has also made football less appealing to females, as they generally lack the muscle and body mass to compete without serious risk. The tackle nature of football also tends to favor the largest and strongest players, along with the fastest. The average weight of players in the NFL has increased in recent years.

All these factors have brought the sport into controversy in the past few decades, joining the group of other "violent" and thus controversial sports such as wrestling, hockey, and boxing. Critics argue that these sports emphasize size, physical strength, and brute force, and also that they breed aggression and unhealthy competitive attitudes in children. Others argue that such sports teach sportsmanship and teamwork, and though contact sports are all violent to some degree, they always emphasize skill and strategy over mere belligerence.

Development of the game

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.

Rugby was first introduced to North America in Canada, brought by the British Army garrison in Montreal which played a series of games with McGill University. Both Canadian and American football evolved from this point. For an in-depth overview of the differences and similarities of Canadian football and American football see: Comparison of Canadian and American football

American colleges spearheaded the growth of football. The first inter-collegiate football game was played between Rutgers and Princeton Universities on November 6, 1869. The game was won by Rutgers (6-4) although "The game, which bore little resemblance to its modern-day counterpart, was played with two teams of 25 men each under rugby-like rules, but like modern football, it was 'replete with surprise, strategy, prodigies of determination, and physical prowess,' to use the words of one of the Rutgers players." - Rutgers Football

American football in its current form grew out of a series of three games between Harvard University and McGill University of Montreal in 1874. McGill played rugby football while Harvard played the Boston Game, which was closer to soccer. As often happened in those days of far from universal rules, the teams alternated rules so that both would have a fair chance. The Harvard players liked having the opportunity to run with the ball, and in 1875 persuaded Yale University to adopt rugby rules for their annual game. In 1876 Yale, Harvard, Princeton, and Columbia formed the Intercollegiate Football Association, which used the rugby code, except for a slight difference in scoring.

In 1880 Walter Camp introduced the scrimmage in place of the rugby scrum. In 1882 the system of downs was introduced to thwart Princeton's and Yale's strategy of controlling the ball without trying to score. In 1883 the number of players was reduced, at Camp's urging, to eleven, and Camp introduced the soon standard arrangement of a seven-man offensive line with a quarterback, two halfbacks, and a fullback.

On September 3, 1895 the first professional football game was played, in Latrobe, Pennsylvania, between the Latrobe YMCA and the Jeannette Athletic Club. (Latrobe won the contest 12-0.).

By the 1890s interlocking offensive formations such as the flying wedge and the practice of teammates physically dragging ball-carrying players forward had made the game extremely dangerous. Despite restrictions on the flying wedge and other precautions, in 1905 eighteen players were killed in games. President Theodore Roosevelt informed the universities that the game must be made safer. To force them to respond to his concerns, he threatened to pressure Congress to make playing football a federal crime.

In 1906, two rival organizing bodies, the Intercollegiate Rules Committee and the Intercollegiate Athletic Association, met in New York; eventually they agreed on several new rules intended to make the game safer, among them the addition of a neutral zone between the scrimmage lines and a requirement that at least six players from each team line up on them. The most far-reaching innovation they considered, though, was the legalization of the forward pass. This was very controversial at the time, much derided by purists. As an alternative means of opening out the play, Walter Camp would have preferred widening the field; but representatives from Harvard pointed to recently constructed Harvard Stadium, which could not be widened, and the forward pass was adopted; it has come to shape the whole history of American football, as opposed to its cousins around the world.

In 1910, after further deaths, interlocking formations were finally outlawed; and in 1912 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. The game had achieved its modern form.

Problems in football

Injuries are more common in American football than in many other sports, although rule changes made in the past 90 years (for instance, the elimination of "horse-collar tackles") have gradually lowered the rates of injuries. In addition, protective equipment has become better - for example, the optional leather helmets introduced during the 1890s have been replaced (in several stages) by required high-tech padded plastic helmets with bars protecting the face. Modern field turf is seen as another danger-adding element in the game of football. Turf offers less "give" than grass, and can exert much greater forces on the players' bodies. While it guarantees a certain state of the play field, and enables players to run faster, it has also been shown to cause more injuries, most notably ankle injuries.

More recently, the use of steroids and the extent thereof has become an object of debate in professional, college, and even high school football leagues.

Another problem with football is that it is an expensive sport. The specialized helmets, uniforms, and pads can cost hundreds of dollars. There is a widespread perception that football teams based in schools and public recreational leagues consume far more than their fair share of the sports budget, although sales of tickets to college (and to some extent high school) football games often make it a revenue-producing sport.

Leagues, Organizations, and Associations

United States

Cleveland Browns Stadium in Cleveland, Ohio, home of the Cleveland Browns.

Football is played at a number of levels in the United States. These include the following:

National Football League (NFL) - the top-level men's professional league
College Football - played at many U.S. colleges and mostly governed by the NCAA. Other organizations include the NAIA and the NJCAA.
Arena Football (AFL) - professional indoor-football league.
American Football Association - semi-pro/minor league
North American Football League - Amateur minor league with more than 100 member organizations since 1996
Women's American football - since 2000, there has been a surge of women's professional leagues.
High School Football - played at most U.S. High Schools
Pop Warner or youth football - involves younger children who are too young to play high school, generally in middle school.
Sprint football - players must weigh no more than 172 pounds
Okinawan Football League - Various football teams made up of U.S. servicemembers
Great Plains Football League (GPFL)- semi-pro/minor league football league based in Rochester, MN with teams in MN, WI, IL, and IA. See http://www.greatplainsfootball.com 

Internationally

American football is also played in many nations around the world. These include:

• International Federation of American Football International governing body for American football with 45 member associations from North and South America, Europe, Asia and Oceania. The IFAF also oversees the World Cup of American football which is held every four years. Japan has won the first two World Cups held in 1999 and 2003.
• Europe
  • NFL Europe - professional league in Europe, playing for the World Bowl (XIV in 2006)
  • European Federation of American Football European organization who runs the Eurobowl (XX in 2006)
  • German Football League
    • List of American football teams in Germany
  • Britain
    • British Collegiate American Football League (BCAFL) - Fast-growing college football league in the UK
    • British American Football League (BAFL) -Higher League of American Football in the UK
    • Irish American-football league
• American Football New Zealand - national body of American Football in New Zealand
• Gridiron Australia - national body of several state-level leagues
• Mexican College Football League or ONEFA - played by many Mexican colleges, with essentially NCAA rules
• Israeli Football League (IFL) - Three teams, Haifa Underdogs, Tel Aviv Pioneers, Tel Aviv Sabres

Alternate Rulesets

Other kinds of American football with modified or derived rules:

• Canadian Football League (CFL) - Canadian men's professional league played using Canadian football rules.
• Arena Football League - mid-level men's professional league played indoors. There is also a "minor league" for Arena Football called AF2.
• National Indoor Football League - Similar to Arena Football, but generally featuring lower echelon players.
• Nine-man football, eight-man football and six-man football - variations of high school football, usually played in sparsely populated areas
• Amateur and youth league football
• Flag football and Touch football - non-tackle; almost exclusively amateur

Non-current Leagues

Professional leagues that no longer exist:

All-America Football Conference (AAFC, 1946-1949) (2 teams are now in the NFL)
American Football Leagues (AFL), four separate ones: I:1926, II: 1937-38, III: 1940-1941 and IV: 1960-1969). The fourth AFL (1960-1969) merged with the NFL in 1970 and now exists (mostly) as the AFC with several new teams. The old NFL appeared as the NFC.
World Football League (WFL, 1974-75)
United States Football League (USFL, 1983-1985)
World League of American Football (WLAF, 1991-1993 — reformed as NFL Europe)
XFL (XFL, 2001)

Footnotes

1. ^ The word "football" in Canada can mean American football or Canadian football depending on context. An Association for Canadian Studies survey finds that more Canadians watch the National Football League than the Canadian Football League (PDF file), but both codes are popular in Canada.
2. ^ MacCambridge, Michael. America's Game, Random House, 2004.

References

• Digest of Rules. National Football League. Retrieved on December 28, 2005.
• History and the basics. National Football League. Retrieved on December 28, 2005.
• Playing with the Percentages When Trailing by Two Touchdowns. Montana State University. Retrieved on December 24, 2005.

External links

• The National Football League (NFL) - the top professional league
• NFL Players Association
• NCAA [2] (complete college football rules are available as a PDF file)
• American Football Coaches Association
• Movie of 1903 football game between the University of Chicago and the University of Michigan
• Chronology of many events in the NFL
• The Women's League
• Annual Survey of Football Injury Research
• Football Basics
• Football FAQ
• Football Plays, Drills & Fundamentals - Resource for coaches & players.
• The American Football Players Directory
• The Israeli Football League (IFL)