American football referred to as football in the United States and Canada and also known as gridiron,[ is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, which is the team controlling the oval-shaped football, attempts to advance down the field by running with or passing the ball, while the defense, which is the team without control of the ball, aims to stop the offense’s advance and aims to take control of the ball for themselves. The offense must advance at least ten yards in four downs or plays, and otherwise, they turn over the football to the defense; if the offense succeeds in advancing ten yards or more, they are given a new set of four downs. Points are primarily scored by advancing the ball into the opposing team’s end zone for a touchdown or kicking the ball through the opponent’s goalposts for a field goal. The team with the most points at the end of a game wins.
American football evolved in the United States, originating from the sports of association football (known in the U.S. as soccer) and rugby football. The first match of American football was played on November 6, 1869, between two college teams, Rutgers and Princeton, under rules based on the association football rules of the time. During the latter half of the 1870s, colleges playing association football switched to the Rugby Union code, which allowed carrying the ball. A set of rule changes drawn up from 1880 onward by Walter Camp, the “Father of American Football”, established the snap, the line of scrimmage, eleven-player teams, and the concept of downs; later rule changes legalized the forward pass, created the neutral zone, and specified the size and shape of the football. The sport is closely related to Canadian football, which evolved parallel and contemporary to the American game, and most of the features that distinguish American football from rugby and soccer are also present in Canadian football.
American football as a whole is the most popular sport in the United States. The most popular forms of the game are professional and college football, with the other major levels being high school and youth football. As of 2012, nearly 1.1 million high school athletes and 70,000 college athletes play the sport in the United States annually, almost all of them men, with a few exceptions. The National Football League, the most popular American football league, has the highest average attendance of any professional sports league in the world; its championship game, the Super Bowl, ranks among the most-watched club sporting events in the world, and the league has an annual revenue of around US$10 billion.
American football Rules
American Football Field and instruments
Football games are played on a rectangular field that measures 120 yards (110 m) long and 53 1⁄3 yards (48.8 m) wide. Lines marked along the ends and sides of the field are known respectively as the end lines and sidelines, and goal lines are marked 10 yards (9.1 m) inward from each end line. Weighted pylons are placed on the inside corner of the intersections of the goal lines and end lines.
White markings on the field identify the distance from the end zone. Inbound lines, or hash marks, are short parallel lines that mark off 1-yard (0.91 m) increments. Yard lines, which can run the width of the field, are marked every 5 yards (4.6 m). A one-yard-wide line is placed at each end of the field; this line is marked at the center of the two-yard line in professional play and at the three-yard line in college play. Numerals that display the distance from the closest goal line in yards are placed on both sides of the field every ten yards.[
Goalposts are located at the center of the plane of each of the two end lines. The crossbar of these posts is 10 feet (3.0 m) above the ground, with vertical uprights at the end of the crossbar 18 feet 6 inches (5.64 m) apart for professional and collegiate play and 23 feet 4 inches (7.11 m) apart for high school play. The uprights extend vertically 35 feet (11 m) on professional fields, a minimum of 10 yards (9.1 m) on college fields, and a minimum of 10 feet (3.0 m) on high school fields. Goal posts are padded at the base, and orange ribbons are normally placed at the tip of each upright.
The football itself is an oval ball, similar to the balls used in rugby or Australian rules football. At all levels of play, the football is inflated to 12 1⁄2 to 13 1⁄2 pounds per square inch (86 to 93 kPa) and weighs 14 to 15 ounces (400 to 430 g); beyond that, the exact dimensions vary slightly. In professional play the ball has a long axis of 11 to 11 1⁄4 inches (28 to 29 cm),
Scoring in American Football
In American football, the winner is the team that has scored more points at the end of the game. There are multiple ways to score in a football game.
The touchdown (TD), worth six points, is the most valuable scoring play in American football. A touchdown is scored when a live ball is advanced into, caught in, or recovered in the end zone of the opposing team. The scoring team then attempts a try or conversion, more commonly known as the point(s)-after-touchdown (PAT), which is a single scoring opportunity.
A PAT is most commonly attempted from the two- or three-yard line, depending on the level of play. If scored by a placekick or dropkick through the goal posts, it is worth one point, and is typically called the extra point. Conversely, a team may elect to run a single play from scrimmage and attempt, once again, to achieve what would normally be considered a touchdown. In such a case, a successful attempt is called the two-point conversion and is worth two points. For the 2015 season, the NFL adopted rules on PATs that stated during an extra point the placekick must be snapped from the 15-yard line and on extra points if the kick is blocked and the opposing team returns it into the end zone or if during a two-point conversion the ball is fumbled or intercepted and returned to the end zone the opposing team will score two points. No points are awarded on a failed extra point or two-point conversion attempt, although under a rare set of circumstances it is possible to score a safety, worth one point, if the defense takes the ball back into its own end zone and is downed there. In general, the extra point is almost always successful in professional play and is only slightly less successful at amateur levels, while the two-point conversion is a much riskier play with a higher probability of failure; accordingly, extra point attempts are far more common than two-point conversion attempts.
A field goal (FG), worth three points, is scored when the ball is placekicked or dropkicked through the uprights and over the crossbars of the defense’s goalposts. After a PAT attempt or successful field goal the scoring team must kick the ball off to the other team.
A safety is scored when the ball carrier is tackled in their own end zone. Safeties are worth two points, which are awarded to the defense. In addition, the team that conceded the safety must kick the ball to the scoring team via a free kick.
Duration and time stoppages in football
American Football games last for a total of 60 minutes in professional and college play and are divided into two halves of 30 minutes and four quarters of 15 minutes. High school football games are 48 minutes in length with two halves of 24 minutes and four quarters of 12 minutes. The two halves are separated by a halftime period, and the first and third quarters are also followed by a short break. Prior to the start of the game, the referee and team captains for each team meet at midfield for a coin toss. The visiting team is allowed to call “heads” or “tails”; the winner of the toss is allowed to decide between choosing whether to receive or kick off the ball or choosing which goal they want to defend, but they can also defer their choice until the second half. The losing team, unless the winning team decides to defer, is allowed to choose the option the winning team did not select, and receives the option to receive, kick, or select a goal to defend to begin the second half. Most teams choose to receive or defer because choosing to kick the ball to start the game would allow the other team to choose which goal to defend.[ Teams switch goals following the first and third quarters. If a down is in progress when a quarter ends, play continues until the down is completed.
Games last longer than their defined length due to play stoppages—the average NFL game lasts slightly over three hours. Time in a football game is measured by the game clock. An operator is responsible for starting, stopping and operating the game clock based on the direction of the appropriate official. A separate clock, the play clock, is used to determine if a delay of game infraction has been committed. If the play clock expires before the ball has been snapped or free-kicked, a delay of game foul is called on the offense. The play clock is set to 40 seconds in professional and college football and to 25 seconds in a high school play or following certain administrative stoppages in the former levels of play.
Kicking in football
There are two categories of kicks in football: scrimmage kicks, which can be executed by the offensive team on any down from behind or on the line of scrimmage, and free kicks. The free kicks are the kickoff, which starts the first and third quarters and overtime and follows a try attempt or a successful field goal, and the safety kick, which follows a safety.
On a kickoff, the ball is placed at the 35-yard line of the kicking team in professional and college play and at the 40-yard line in high school play. The ball may be drop-kicked or place-kicked. If a place kick is chosen, the ball can be placed on the ground or on a tee, and a holder may be used in either case. On a safety kick, the kicking team kicks the ball from their own 20-yard line. They can punt, drop-kick or place-kick the ball, but a tee may not be used in professional play. Any member of the receiving team may catch or advance the ball, and the ball may be recovered by the kicking team once it has gone at least ten yards and has touched the ground or has been touched by any member of the receiving team.
The three types of scrimmage kicks are place kicks, drop kicks, and punts. Only place kicks and drop kicks can score points. The place kick is the standard method used to score points, because the pointy shape of the football makes it difficult to reliably drop kick. Once the ball has been kicked from a scrimmage kick, it can be advanced by the kicking team only if it is caught or recovered behind the line of scrimmage. If it is touched or recovered by the kicking team beyond this line, it becomes dead at the spot where it was touched.The kicking team is prohibited from interfering with the receiver’s opportunity to catch the ball, and the receiving team has the option of signaling for a fair catch. This prohibits the defense from blocking into or tackling the receiver, but the play ends as soon as the ball is caught and the ball may not be advanced.
ow many players are there in this game?
Although there are only 11 players from each side on the field at any one time, an American football team is made up of 45 players, ranging in size, speed and their roles within the team.
When is the season to play this game?
NFL regular season. The National Football League (NFL) regular season begins on the weekend following the first Monday of September (i.e, the weekend following the Labor Day holiday) and ends in December or early January. It consists of 256 games, where each team (32 total) plays 16 games during a 17-week period.
What is the dress code of A. football?
Basic equipment worn by most football players include helmet, shoulder pads, gloves, shoes, and thigh and knee pads,a mouthguard, and a jockstrap or compression shorts with or without a protective cup.