In gridiron football, the chain crew (commonly known as the "chain gang") is a crew that manages signal poles on one of the sidelines.
The chain crew, under the direction of the head linesman/down judge, signals the officials' decisions; it does not make decisions. Players look to the chain crew to see the down number and the line to gain. Officials may rely on the chain crew after a play (incomplete pass or penalty) whose outcome depends on the original spot of the ball.
Three members of the chain crew hold poles upright. The bottom of each pole is placed along a sideline to denote a line across the gridiron to the opposite sideline.
There may be additional chain crew members. A "clip man" is discussed below. In the NFL, additional chain crew members have additional tasks, such as to relieve the line judge of the clerical task of recording all assessed penalties.Despite the use of "man" in the colloquial terms for the chain crew positions, women can perform any of them.
Members of the chain crew are usually picked by the offices of the home team instead of the league or conference. In the NFL, members of the chain crew must have credentials entitling them to access to the field, and must wear white shirts. The home team pays them; some teams pay an hourly wage and others pay a flat rate to work a game.
The chain crew does not wear protective gear as players do. A routine instruction by officials to the chain crew is to withdraw or drop their signals, and move back, if the play comes toward them so as to endanger them. Often, the signals use bright orange color, are padded, and have break-away components for safety.
For games at all levels except the NFL and NCAA, the chain crew operates on the side of the field opposite the press box (usually the visiting team's sideline).
In the NFL, the chain crew switches sides at halftime; the referee determines their initial placement. On fields where both teams' benches are located on the same side of the field, the chain crew operates on the opposite side for the entire game (no NFL stadium has had benches on the same side since the Green Bay Packers stopped playing three games a year at Milwaukee County Stadium following the 1994 season; the last full-time stadium to have this setup was the Minnesota Vikings' Metropolitan Stadium, which closed following the 1981 season).
In the NCAA, the chain crew operates on the same side as the press box in the first half and the opposite side in the second. This practice started in 2014.
In the NFL and other venues where there is a zone behind the sidelines, all three poles are placed somewhere along the back line of this zone. Otherwise, the poles are placed along the sideline.
For professional and college football games, an auxiliary chain crew operates on the opposite side of the field, supervised by the line judge. Their presence lets players and officials look to either side of the field for information. The auxiliary chain crew also includes the drive start indicator, which is placed at the beginning of a team's drive and stays there until the team loses possession. This indicator is only used for statistical purposes to calculate the distance of each drive. It looks similar to a "stick" and has an arrow (or occasionally a large "X") that points in the direction the offensive team is going.
The NFL previously used an additional fourth chain crew member, which held a rod marked with an X to mark the spot of the last drive start. The X marker was eliminated in 2018.
At the start of a series of downs, the linesman stands so that the heel of one foot marks the initial line of scrimmage. The box man places his indicator to mark this position and sets the box to display "1". The operator of the rear rod marks the same position, while the other rod man moves ten yards toward the defense's goal line to mark the line to gain.
The linesman, the box man, or a fourth member of the chain crew attaches a "clip" to the chain to line up with the rear edge of the closest five-yard line to the rear rod.A device on the clip indicates which numbered line this is. The clip and the device let the chain crew restore the position of the rods after a mishap. In leagues such as the NFL with Instant Replay, there may be multiple clips to let the rods be repositioned after a play is reviewed and reversed.
After a typical play, the box man increments the displayed number and realigns that pole to the new line of scrimmage, again as directed by the linesman. After a play that results in a first down, all three members move and reset their signals to mark a new series of downs.
The chain crew must not move until the referee or linesman signals whether the play finished without a penalty. On a penalty, the chain crew stays put so that the officials can see the original state. When the referee and linesman walk off the appropriate number of yards, the box man moves as well. The box man does not change the number displayed, except on a penalty that results in a loss of down. On a penalty that results in a first down, the entire chain crew moves and resets.
When possession of the ball switches to the other team, the forward rod becomes the rear rod and vice versa to minimize the distance the rod men have to move. However, at the end of the first and third quarters, when players switch directions on the field, the chain crew also moves (for example, a marker may move from one 32-yard line to the other 32-yard line). The rear rod man moves past the forward rod man and continues to mark the start of the series of downs, in the new orientation. The linesman and other officials supervise this movement, using one or more clips to exactly reposition the chains.
On plays where there is no line to gain (a series of downs that starts within 10 yards of the goal line, a try after touchdown, or a kickoff), the rod men lower or lay down their signals, but the box man continues to mark the line of scrimmage.
The chains are brought onto the field whenever the referee needs an accurate measurement to determine if a first down has been made. A team may also request an accurate measurement to determine how far they have to reach for the first down.
Before the game, many linesmen attach a piece of tape at the midpoint of the chain. 6.10.1The linesman can compare the line of scrimmage to this mark at the start of a play and know whether a 5-yard penalty against the defense will result in a first down. If so, the linesman's typical hand signal to the line judge across the field is to extend the arms with the thumbs pointing toward one another. Such a gesture with thumbs pointing away signals that there are more than 5 yards to gain. :
All levels of organized football use the chain crew. One notable exception at the professional level was the World Football League of 1974 to 1975, which used the "Dicker-rod," a proprietary, 90-inch stick that allowed measurements to be made with one person instead of three. The Dicker-rod was never used outside the WFL.
The "box" (down marker) has evolved over time. In the pre-television era, it was a rod (shorter than the height of the operator) with a triangular pointer that rotated to show the official the down number. It was replaced with a much larger, two-sided flipper system when television became widespread; flipper-style down markers are still in use in scholastic and amateur football. A more modern model is the Dial-a-Down, in which compact levers display a new down number over the entire face of the "box"; this model is used at most college and professional games.Electronic down markers using LEDs are emerging as the next advance. However, further application of technology to measure the lengthwise position of the football, such as sensors inside the football, may be resisted based on affection for the human element. Early attempts and proposals to use precision automatic chain instruments were hindered both by costs and potential hazards (early proposals required metal rails; a 1990s system used visible lasers). Lazser Down, a system that uses wideband radio waves to precisely spot and measure distances, has seen some rollout in college football, the Alliance of American Football and the XFL.
Canadian football 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.
A linebacker is a playing position in gridiron football. Linebackers are members of the defensive team, and line up approximately three to five yards behind the line of scrimmage, behind the defensive linemen, and therefore "back up the line". The different responsibilities of outside linebackers in the 3–4 and 4–3 defenses usually lead to very different skill sets and body types being sought out by teams as to best fit their particular defenses. 3–4 OLBs are generally, or primarily required to play North to South, are lankier/taller, bulkier and stronger/more powerful as to effectively aid the ends in setting the edge on running plays and provide pressure to the quarterback on passing plays, and will usually have an arsenal of pass rush moves used primarily against the blockers the offense has on the edge of their line. 4–3 OLBs generally are expected to more proficiently move East to West more often and therefore are usually rangier players more adept in covering potential receiving targets off the line or from the backfield, as well as having outside contain beyond the tackle box on run plays. Linebackers generally align themselves before the ball is snapped by standing upright in a "two-point stance".
Gridiron football, also known as North American football or, in North America, simply football, is a family of football team sports primarily played in the United States and Canada. American football, which uses 11-player teams, is the form played in the United States and the best known form of gridiron football worldwide, while Canadian football, featuring 12-player teams, predominates in Canada. Other derivative varieties include indoor football and Arena football, football for smaller teams, and informal games such as touch and flag football. Football is played at professional, collegiate, high school, semi-professional, and amateur levels.
A down is a period in which a play transpires in gridiron football. The down is a distinguishing characteristic of the game compared to other codes of football, but is synonymous with a "tackle" in rugby league. The team in possession of the football has a limited number of downs to advance ten yards or more towards their opponent's goal line. If they fail to advance that far, possession of the ball is turned over to the other team. In most situations, if a team reaches their final down they will punt to their opponent, which forces them to begin their drive from further down the field; if they are in range, they might instead attempt to score a field goal.
This is a glossary of terms used in Canadian football. The Glossary of American football article also covers many terms that are also used in the Canadian version of the game.
American and Canadian football are gridiron codes of football that are very similar; both have their origins in rugby football, but some key differences exist.
Gameplay in American football consists of a series of downs, individual plays of short duration, outside of which the ball is dead or not in play. These can be plays from scrimmage – passes, runs, punts, or field goal attempts – or free kicks such as kickoffs and fair catch kicks. Substitutions can be made between downs, which allows for a great deal of specialization as coaches choose the players best suited for each particular situation. During a play, each team should have no more than 11 players on the field, and each of them has specific tasks assigned for that specific play.
In gridiron football, clock management is the manipulation of a game clock and play clock to achieve a desired result, typically near the end of a match. It is analogous to "running out the clock" seen in many sports, and the act of trying to hasten the game's end is often referred to by this term. Clock management strategies are a significant part of American football, where an elaborate set of rules dictates when the game clock stops between downs, and when it continues to run.
In gridiron football, an official is a person who has responsibility in enforcing the rules and maintaining the order of the game.
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.
The 1972 NFL season was the 53rd regular season of the National Football League. The Miami Dolphins became the first NFL team to finish a championship season undefeated and untied when they beat the Washington Redskins in Super Bowl VII.
Jerry Markbreit is a former American football referee in the National Football League (NFL) for 23 seasons and became one of the most recognizable referees in the game. Markbreit officiated football games for 43 seasons. From 1965 to 1975, Markbreit officiated college football games in the Big Ten Conference. He then joined the NFL in 1976 as a line judge on the crew of Tommy Bell before being promoted to the head referee position in just his second year. His uniform number in the league was 9, which is now worn by Mark Perlman. In his 23 seasons in the NFL, Markbreit had 25 postseason assignments: two wild card games, 10 divisional games, eight conference championships, one Pro Bowl (1978), and four Super Bowls: Super Bowl XVII, Super Bowl XXI, Super Bowl XXVI, and Super Bowl XXIX and was an alternate in Super Bowl XIX, Super Bowl XXII, and Super Bowl XXVIII. To date, he is the only NFL head referee to officiate four Super Bowl games.
A comparison of American football and rugby union is possible because of the games' shared origins, despite their dissimilarities.
The rectangular field of play used for American football games measures 100 yards (91.44 m) long between the goal lines, and 160 feet (48.8 m) wide. The field is made of grass. In addition, there are end zones extending another 10 yards (9.144 m) past the goal lines to the "end lines", for a total length of 120 yards (109.7 m). When the "football field" is used as unit of measurement, it is usually understood to mean 100 yards (91.44 m), although technically the full length of the official field, including the end zones, is 120 yards (109.7 m). There is a goal centered on each end line, with a crossbar 10 feet (3.0 m) above the ground and goalposts 18 feet 6 inches (5.64 m) apart extending at least 35 feet (11 m) above the crossbar. Between the goal lines, additional lines span the width of the field at 5-yard intervals. These lines give the football field an appearance resembling that of a gridiron, which gives rise to "gridiron" being a nickname for a football field and for the sport itself.
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.
American football, referred to simply 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, the team with possession of the oval-shaped football, attempts to advance down the field by running with the ball or passing it, while the defense, the team without possession of the ball, aims to stop the offense's advance and to take control of the ball for themselves. The offense must advance at least ten yards in four downs or plays; if they fail, they turn over the football to the defense, but if they succeed, they are given a new set of four downs to continue the drive. Points are scored primarily 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.
In gridiron football, a penalty is a sanction called against a team for a violation of the rules, called a foul. Officials initially signal penalties by tossing a bright yellow or orange colored penalty flag onto the field toward or at the spot of a foul. Many penalties result in moving the football toward the offending team's end zone, usually either 5, 10, or 15 yards, depending on the penalty. Most penalties against the defensive team also result in giving the offense an automatic first down, while a few penalties against the offensive team cause them to automatically lose a down. In some cases, depending on the spot of the foul, the ball is moved half the distance to the goal line rather than the usual number of yards, or the defense scores an automatic safety.
In gridiron football, a punt is a kick performed by dropping the ball from the hands and then kicking the ball before it hits the ground. The most common use of this tactic is to punt the ball downfield to the opposing team, usually on the final down, with the hope of giving the receiving team a field position that is more advantageous to the kicking team when possession changes. The result of a typical punt, barring any penalties or extraordinary circumstances, is a first down for the receiving team. A punt is not to be confused with a drop kick, a kick after the ball hits the ground, now rare in both American and Canadian football.
The American Flag Football League is a semi-professional flag football league started in 2017. The league was founded by Jeff Lewis in May 2017. Lewis spent nine months building the league, getting investors, setting the rules, and finding players and broadcasting partners. The league has signed a deal to air its games on the NFL Network.
Rule 1, Section 5: Chain Crew and Ball Boys/Girls