In American football and Canadian football, not all players on offense are entitled to receive a forward pass. Only an eligible pass receiver may legally catch a forward pass, and only an eligible receiver may advance beyond the neutral zone if a forward pass crosses into the neutral zone. If the pass is received by a non-eligible receiver, it is "illegal touching" (five yards and loss of down). If an ineligible receiver is beyond the neutral zone when a forward pass crossing the neutral zone is thrown, a foul of "ineligible receiver downfield" (five yards, but no loss of down) is called. Each league has slightly different rules regarding who is considered an eligible receiver.
The NCAA rulebook defines eligible receivers for college football in Rule 7, Section 3, Article 3. The determining factors are the player's position on the field at the snap and their jersey number. Specifically, any players on offense wearing numbers between 50 and 79 are always ineligible. All defensive players are eligible receivers and offensive players who are not wearing an ineligible number are eligible receivers if they meet one of the following three criteria:
If a player is to change between eligible and ineligible positions, they must physically change jersey numbers to reflect the position.
A receiver loses his eligibility by leaving the field of play unless he was forced out by a defensive player and immediately attempts to get back inbounds (Rule 7-3-4). All players on the field become eligible as soon as the ball is touched by a defensive player or an official during play (Rule 7-3-5).
In both American and Canadian professional football, every player on the defensive team is considered eligible. The offensive team must have at least seven players lined up on the line of scrimmage. Of the players on the line of scrimmage, only the two players on the ends of the line of scrimmage are eligible receivers. The remaining players are in the backfield (four in American football, five in Canadian football), including the quarterback. These backfield players are also eligible receivers. In the National Football League, a quarterback who takes his stance behind center as a T-formation quarterback is not eligible unless, before the ball is snapped, he legally moves to a position at least one yard behind the line of scrimmage or on the end of the line, and is stationary in that position for at least one second before the snap, but is nonetheless not counted toward the seven men required on the line of scrimmage.
If, for example, eight men line up on the line of scrimmage, the team loses an eligible receiver. This can often happen when a flanker or slot receiver, who is supposed to line up behind the line of scrimmage, instead lines up on the line of scrimmage between the offensive line and a split end. In most cases where a pass is caught by an ineligible receiver, it is usually because the quarterback was under pressure and threw it to an offensive lineman out of desperation.
In many leagues eligible receivers must wear certain uniform numbers, so that the officials can more easily distinguish between eligible and ineligible receivers. In the NFL running backs must wear numbers 20 to 49, tight ends must wear numbers 80 to 89 (or 40 to 49 if the numbers 80 to 89 have been exhausted), and wide receivers must wear numbers 10 to 19 or 80 to 89. In the CFL ineligible receivers must wear numbers 50 to 69; all other numbers (including 0 and 00) may be worn by eligible receivers. A player who is not wearing a number that corresponds to an eligible receiver is ineligible even if he lines up in an eligible position. However, a player who reports to the referee that he intends to be eligible in the following play is allowed to line up and act as an eligible receiver. An example of this was a 1985 NFL game in which William Perry, wearing number 72 and normally a defensive lineman, was made an eligible receiver on an offensive play, and successfully caught a touchdown pass attempt. A more recent example, and more commonly used, has been former New England Patriots linebacker Mike Vrabel lining up as a tight end in goal line situations. In the 2018 season, George Fant has also lined up in the tight end position for the Seattle Seahawks due to injuries to the starting tight ends Ed Dickson and Will Dissly. 
Before the snap of the ball, in the American game, backfield players may only move parallel to the line of scrimmage, only one back may be in motion at any given time, and if forward motion has occurred, the back must be still for a full second before the snap. The receiver may be in motion laterally or away from the line of scrimmage at the snap. A breach of this rule results in a penalty for illegal procedure (five yards). However, in the Canadian game, eligible receivers may move in any direction before the snap, any number may be in motion at any one time, and there is no need to be motionless before the snap.
The rules on eligible receivers only apply to forward passes. Any player may legally catch a backwards or lateral pass.
In the American game, once the play has started, eligible receivers can become ineligible depending on how the play develops. Any eligible receiver that goes out of bounds is no longer an eligible receiver and cannot receive a forward pass, unless that player re-establishes by taking three steps in bounds. Also, if a pass is touched by any defensive player or eligible offensive receiver (tipped by a defensive lineman, slips through a receiver's hands, etc.), every offensive player immediately becomes eligible. In the CFL all players become eligible receivers if a pass is touched by a member of the defensive team.
A proposed rule change in the XFL would make all players behind the line of scrimmage eligible receivers, regardless of position or number.
In high school football, the rules of eligibility are roughly the same as in the college game. However, as of February 1999, at least five players must wear numbers between 50 and 79 on first, second, or third down, which by rule would make them ineligible receivers. This was because of a change in the definition of a scrimmage-kick formation made by the National Federation of State High School Associations (NFHS). The change was intended to close a loophole in the rules which allowed teams to run an A-11 offense, in which a team could legally be exempted from eligibility numbering restrictions if the player receiving the snap was at least seven yards behind the line of scrimmage.
|Positions in American football and Canadian football|
|Offense (Skill position)||Defense||Special teams|
|Linemen||Guard, Tackle, Center||Linemen||Tackle, End||Kicking players||Placekicker, Punter, Kickoff specialist|
|Quarterback (Dual-threat, Game manager, System)||Linebacker||Snapping||Long snapper, Holder|
|Backs||Halfback/Tailback (Triple-threat), Fullback, H-back, Wingback||Backs||Cornerback, Safety, Halfback, Nickelback, Dimeback||Returning||Punt returner, Kick returner, Jammer, Upman|
|Receivers||Wide receiver (Eligible), Tight end, Slotback, End||Tackling||Gunner, Upback, Utility|
|Formations (List) — Nomenclature — Strategy|
Canadian football (French: football canadien) is a sport played in Canada in which two teams of 12 players each compete for territorial control of a field of play 110 yards (101 m) long and 65 yards (59 m) wide attempting to advance a pointed oval-shaped ball into the opposing team's scoring area (end zone).
In Canada, the term "football" may refer to Canadian football and American football collectively, or to either sport specifically, depending on context. The two sports have shared origins and are closely related but have some key differences.
Rugby football in Canada originated in the early 1860s, and over time, the game known as Canadian football developed. Both the Canadian Football League (CFL), the sport's top professional league, and Football Canada, the governing body for amateur play, trace their roots to 1880 and the founding of the Canadian Rugby Football Union.
The CFL is the most popular and only major professional Canadian football league. Its championship game, the Grey Cup, is one of Canada's largest sporting events, attracting a broad television audience. In 2009, about 40% of Canada's population watched part of the game; in 2014, it was closer to 33%, peaking at 5.1 million viewers in the fourth quarter.Canadian football is also played at the bantam, high school, junior, collegiate, and semi-professional levels: the Canadian Junior Football League, formed May 8, 1974, and Quebec Junior Football League are leagues for players aged 18–22, many post-secondary institutions compete in U Sports football for the Vanier Cup, and senior leagues such as the Alberta Football League have grown in popularity in recent years. Great achievements in Canadian football are enshrined in the Canadian Football Hall of Fame located in Hamilton, Ontario.
Other organizations across Canada perform senior league Canadian football during the summer.Clipping (gridiron football)
In gridiron football, clipping is the act of a "throwing the body across the back of the leg of an eligible receiver or charging or falling into the back of an opponent below the waist after approaching him from behind, provided the opponent is not a runner." It is also clipping to roll up on the legs of an opponent after a block. It is usually illegal, but in the National Football League it is legal to clip above the knee in close-line play. The Canadian Football League has similar definitions, prohibitions and exceptions, including that "application of [a] penalty is determined by the initial contact".In most leagues, the penalty is 15 yards, and if committed by the defense, an automatic first down. It is prohibited because it has the potential to cause injury. Injuries that can be caused by a clipping violation include those to the collateral and cruciate ligaments and the meniscus. Clipping was first banned in 1916 in the NCAA, and rules prohibiting it gradually went into effect in various leagues in the years that followed. In recent years, clipping has not been called as a penalty as much as a block in the back.Eligibility
Eligibility may refer to:
The right to run for office (in elections), sometimes called passive suffrage or voting eligibility
Desirability as a marriage partner, as in the term eligible bachelor
Validity for participation, as in eligibility to enter a Competition
Eligibility for the NBA draft
Eligible receiver, gridiron football rules for catching a pass
NCAA eligibility, requirements to play college sports in the National Collegiate Athletic Association
FIFA eligibility rules, requirement to play for a national team in association footballEligible Receiver 97
Eligible Receiver 97 was a U.S. government exercise conducted under what is known as the No-Notice Interoperability Exercise Program. The exercises were held June 9–13, 1997 and included participants such as the National Security Agency (which acted as the Red Team), Central Intelligence Agency, Defense Intelligence Agency, Federal Bureau of Investigation, National Reconnaissance Office, Defense Information Systems Agency, Department of State, Department of Justice, as well as critical civilian infrastructure providers such as power and communication companies.
The NSA Red Team used hacker techniques and software that was freely available on the Internet at that time. The Red Team was able to crack networks and do things such as deny services; change and manipulate emails to make them appear to come from a legitimate source; disrupt communications between the National Command Authority, intelligence agencies, and military commands. Common vulnerabilities were exploited which allowed the Red Team to gain root access to over 36 government networks which allowed them to change/add user accounts and reformat server hard drives.
National Security Agency Red Team had no inside information to work with, but by engaging in extensive preliminary electronic reconnaissance of target agencies and sites prior to the attacks, they were able to inflict considerable simulated damage. Although many aspects of Eligible Receiver remain classified, it is known that the Red Team was able to infiltrate and take control of U.S. Pacific Command computer systems as well as power grids and 911 systems in nine major U.S. Cities.End (gridiron football)
An end in American and Canadian football is a player who lines up at either end of the line of scrimmage, usually beside the tackles. Rules state that a legal offensive formation must always consist of seven players on the line of scrimmage and that the player on the end of the line constitutes an eligible receiver.
Before the advent of two platoons, in which teams fielded distinct defensive and offensive units, players that lined up on the ends of the line on both offense and defense were referred to simply as "ends". The position was used in this sense until roughly the 1960s.On offense, an end who lines up close to the other linemen is known as a tight end and is the only lineman who aside from blocking can run or catch passes. One who lines up some distance from the offensive line is known as a split end. In recent years and the proliferation of the forward pass, the term wide receiver covers both split ends and flankers (wide receivers who line up in split positions but behind the line of scrimmage). The terms “split end” and “flanker” are often replaced today with terms like "X" and "Z" receivers. Bill Carpenter was the first "Lonesome end."
On defense, there is a commonly used position called the defensive end. Its primary role is to rush the passer, as well as to stop offensive runs to the outer edges of the line of scrimmage (most often referred to as "containment"). However, as there are no rules regulating the formation of the defense, players at this position commonly take on and share multiple roles with other positions in different defensive schemes.Flat route
A flat route is an American football route, used in passing plays. A flat route is usually run by a running back or a fullback. When run by a receiver it can be known as a speed out or arrow route. The eligible receiver runs parallel to the line of scrimmage till near the sidelines (in the flat) and turns toward the quarterback to wait for the pass. The QB's pass should arrive when he has not yet past the line of scrimmage. The receiver will then turn upfield at the sideline and run straight down the field.
The route is used, sometimes as a safety relief if post are covered, with long post, long corner or fly routes, so the safeties and the cornerbacks should be upfield when the pass is caught by the RB or FB. There should be a linebacker covering the RB/FB on these kinds of plays, which is likely to be an easy match for an elusive runner like the running back.Formation (American football)
A formation in football refers to the position players line up in before the start of a down. There are both offensive and defensive formations and there are many formations in both categories. Sometimes, formations are referred to as packages.Forward pass
In several forms of football a forward pass is a throwing of the ball in the direction that the offensive team is trying to move, towards the defensive team's goal line. The forward pass is one of the main distinguishers between gridiron football (American football and Canadian football) in which the play is legal and widespread, and rugby football (union and league) from which the North American games evolved, in which the play is illegal.
In some football codes, such as association football (soccer), the kicked forward pass is used so ubiquitously that it is not thought of as a distinct kind of play at all. In these sports, the concept of offside is used to regulate who can be in front of the play or be nearest to the goal. However, this has not always been the case. Some earlier incarnations of football allowed unlimited forward passing, while others had strict offside rules similar to rugby.
The development of the forward pass in American football shows how the game has evolved from its rugby roots into the distinctive game it is today. Illegal and experimental forward passes had been attempted as early as 1876, but the first legal forward pass in American football took place in 1906, after a change in rules. Another change in rules occurred on January 18, 1951, which established that no center, tackle, or guard could receive a forward pass (unless such a player announces his intent to the referee he will be an eligible receiver, called a tackle-eligible play). Today, the only linemen who can receive a forward pass are the tight ends. Current rules regulate who may throw and who may receive a forward pass, and under what circumstances, as well as how the defensive team may try to prevent a pass from being completed. The primary pass thrower is the quarterback, and statistical analysis is used to determine a quarterback's success rate at passing in various situations, as well as a team's overall success at the "passing game."Fullback (gridiron football)
A fullback (FB) is a position in the offensive backfield in American and Canadian football, and is one of the two running back positions along with the halfback. Typically, fullbacks are larger than halfbacks and in most offensive schemes their duties are split between power running, pass catching, and blocking for both the quarterback and the other running back.Many great runners in the history of American football have been fullbacks, including Jim Brown, Marion Motley, Jim Taylor, Franco Harris, Larry Csonka, John Riggins, Christian Okoye, and Levi Jackson. However, many of these runners would retroactively be labeled as halfbacks, due to their position as the primary ball carrier; they were primarily listed as fullbacks due to their size and did not often perform the run-blocking duties expected of modern fullbacks. Examples of players who have excelled at the hybrid running-blocking-pass catching role include Mike Alstott, Daryl Johnston, and Lorenzo Neal.Glossary of American football
The following terms are used in American football, both conventional and indoor. Some of these terms are also in use in Canadian football; for a list of terms unique to that code, see Glossary of Canadian football.Guard (American and Canadian football)
In American and Canadian football, a guard (G) is a player who lines up between the center and the tackles on the offensive line of a football team on the line of scrimmage used primarily for blocking. Right guards (RG) is the term for the guards on the right of the offensive line, while left guards (LG) are on the left side. Guards are to the right or left of the center.
The guard's job is to protect the quarterback from the incoming linemen during pass plays, as well as creating openings (holes) for the running backs to head through. Guards are automatically considered ineligible receivers, so they cannot intentionally touch a forward pass, unless it is to recover a fumble or is first touched by a defender or eligible receiver.Halfback (American football)
A halfback (HB) is an offensive position in American football, whose duties involve lining up in the backfield and carrying the ball on most rushing plays, i.e. a running back. When the principal ball carrier lines up deep in the backfield, and especially when that player is placed behind another player (usually a blocking back), as in the I formation, that player is instead referred to as a tailback (see History below).The halfback position is one of the more glamorous positions on the field, and is commonly viewed as a requirement for a team's success. Sometimes the halfback can catch the ball from the backfield on short passing plays as he is an eligible receiver. Occasionally, they line up as additional wide receivers. When not running or catching the ball, the primary responsibility of a halfback is to aid the offensive linemen in blocking, either to protect the quarterback or another player carrying the football.Halfback option play
The halfback option play is an unorthodox play in American and Canadian football. It resembles a normal running play, but the running back has the option to throw a pass to another eligible receiver before crossing the line of scrimmage.
The key to the play is fooling the defensive players, primarily the defensive backs. If the linebackers and/or the defensive line are fooled and believe the ball carrier is attempting a run, they will pursue the runner, abandoning their pass defense responsibilities and thereby leaving pass receivers uncovered. If the defensive backs are not fooled, the running back carrying the ball does have the option to run, instead of risking an incomplete pass or an interception. This play is not as popular as it once was as defensive players are expected to cover receivers until the football crosses the line of scrimmage on running plays.
The running play that halfback options usually resemble is a sweep play. Sometimes the quarterback will run out of the backfield and become a receiving option for the running back. This can be effective because the quarterback usually does very little after handing off or pitching the ball to the running back on most plays, and the defense might not be expecting him to be used as an active receiver. In the National Football League, if the quarterback starts the play under center, then he is ineligible as a receiver; the quarterback must start from the shotgun to receive a pass. (However, in other leagues, the person under the snapper is an eligible receiver, and this restriction does not apply.)The halfback option play usually has limited success and is not commonly used, especially in the NFL. The play almost completely relies on the element of surprise and better coaching has resulted in defensive backs being instructed to stay in coverage until the running back with the ball crosses the line of scrimmage. Another reason is that the passing ability of most running backs is usually poor in relation to the passing ability of a quarterback. However, certain teams and players do successfully run the option one to a few times a season; used sparingly it can be effective to make a game-changing play. In modern professional football history a halfback has only thrown more than one touchdown in two games: utility player Gene Mingo of the Denver Broncos threw two touchdowns as a halfback in an American Football League game against the Buffalo Bills in 1961; and running back Walter Payton of the Chicago Bears threw two touchdowns in a 1983 NFL game against the New Orleans Saints.
The halfback option play is an integral part of the wildcat offense, which involves the halfback receiving a direct snap.Intentional grounding
In gridiron football, intentional grounding is a violation of the rules where "a passer...throws a forward pass without a realistic chance of completion." This typically happens when a quarterback about to be sacked passes the ball toward an area of the field with no eligible receiver. Were it not for this rule, the quarterback could easily turn the sack into an incomplete pass which, by rule, would advance the ball back to the line of scrimmage and stop the clock.Pass interference
In American and Canadian gridiron football, pass interference (PI) is a foul that occurs when a player interferes with an eligible receiver's ability to make a fair attempt to catch a forward pass. Pass interference may include tripping, pushing, pulling, or cutting in front of the receiver, covering the receiver's face, or pulling on the receiver's hands or arms. It does not include catching or batting the ball before it reaches the receiver. Once the ball touches any defensive player or eligible offensive receiver the above rules no longer apply and the defender may tackle the receiver or attempt to prevent him from gaining control of the ball.
Once a forward pass is in the air it is a loose ball and thus any eligible receiver – all defensive players are eligible receivers – may try to catch it. When a defensive player catches a forward pass it is an interception and his team gains possession of the ball. Some actions that are defined as pass interference may be overlooked if the defender is attempting to catch or bat the ball rather than focusing on the receiver.
The intended receiver may find himself a defender if a defensive player has a better chance to catch a forward pass. If an offensive player commits pass interference against a defensive player attempting to intercept a forward pass it is offensive pass interference.Quarterback sack
In American football and Canadian football, a sack occurs when the quarterback (or another offensive player acting as a passer) is tackled behind the line of scrimmage before he can throw a forward pass, when the quarterback is tackled behind the line of scrimmage in the "pocket" and his intent is unclear, or when a passer runs out of bounds behind the line of scrimmage due to defensive pressure. This often occurs if the opposing team's defensive line, linebackers or defensive backs are able to apply pass pressure (also called a pass rush) to quickly get past blocking players of the offensive team (the quarterback's protection), or if the quarterback is unable to find a back to hand the ball off to or an available eligible receiver (including wide receivers, running backs and tight ends) to catch the ball, allowing the defense a longer opportunity to tackle the quarterback.
Performing a sack is advantageous for the defending team as the offense loses a down, and the line of scrimmage retreats several yards. Even better for the defense is a sack causing the quarterback to fumble the ball at or behind the line of scrimmage; this is also known as a strip sack and can result in a turnover if the defense manages to obtain the ball. A quarterback that is pressured but avoids a sack can still be adversely affected by being forced to hurry.
In the National Football League (NFL), it is possible to record a sack for zero yards. The QB must pass the statistical line of scrimmage to avoid the sack. If a passer is sacked in his own end zone, the result is a safety and the defending team is awarded two points, unless the football is fumbled and either recovered in the end zone by the defense for a touchdown or recovered by either team outside the end zone.Rich Seubert
Richard T. "Rich" Seubert (; born March 30, 1979) is a former American football guard who played his entire career with the New York Giants of the National Football League.Single-wing formation
In American and Canadian football, a single-wing formation, created by Glenn "Pop" Warner, was a precursor to the modern spread or shotgun formation. The term usually connotes formations in which the snap is tossed rather than handed—formations with one wingback and a handed snap are commonly called "wing T" or "winged T". The single wing was superior to the T formation in its ability to get an extra eligible receiver down field.Tackle-eligible play
In football, the tackle-eligible play is a forward-pass play in which coaches will attempt to create mismatches against a defense by inserting an offensive tackle (who is not normally allowed more than five yards down field on a forward-pass play), into an offensive formation as an eligible receiver, usually as a tight end or as a fullback. This is done by changing the formation of the offensive line, via positioning two linemen (including the "catching tackle") on one side of the center and three linemen on the other.
Under almost all versions of gridiron football, offensive linemen cannot receive or touch forward passes, nor can they advance downfield in passing situations. To identify which receivers are eligible and which are not, football rules stipulate that ineligible receivers must wear a number between 50 and 79. However, in some leagues, normally ineligible receivers may align as an eligible receiver provided they inform the referee of such a change. Typically, a player must leave the field for a single play before returning to their original position.