In American football

American football

American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team's end zone. Known in the United States simply as football, it may also be referred to informally as gridiron football. The ball can be advanced by...

, the chain crew (commonly known as the "chain gang") are assistants to the referee

Official (American football)

In American football, an official is a person who has responsibility in enforcing the rules and maintaining the order of the game.During professional and college football games, seven officials operate on the field...

 who handle the first down measuring chain and the down indicator box. The members of the chain crew who operate the measuring chain are called rod men and the person who works the down indicator box is called the box man.

The down indicator box is a pole with a sign indicating what the current down

Down (football)

A down is a period in which a play transpires in American and Canadian football.-Description:A down begins with a snap or free kick , and ends when the ball or the player in possession of it is declared down by an official, a team scores, or the ball or player in possession of it leaves the field...

 is. Before every play from scrimmage

Play from scrimmage

A play from scrimmage is the activity of the games of Canadian football and American football during which one team tries to advance the ball or to score, and the other team tries to stop them or take the ball away. Once a play is over, and before the next play starts, the football is considered...

, it is placed on the sideline to mark the current line of scrimmage

Line of scrimmage

In American and Canadian football a line of scrimmage is an imaginary transverse line beyond which a team cannot cross until the next play has begun...

.

The first down measuring chain is used to measure the yards that the offensive team needs to gain a first down. It is a 10-yard metal chain with poles attached to each end. The poles, usually called "the sticks", are almost always covered in bright orange padding.

When a team gains a first down, one of the rod men places one end of the chain on the sideline parallel to the spot of the ball. The other rod man then stretches the chain out to mark the first down line. To ensure an accurate measurement, a clip is usually attached to the chain on the closest 5-yard mark on the field.

The chains will be brought directly 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.

For games at all levels below the NFL, the chain crew operates on the side of the field opposite the press box. In the NFL, the chain crew switches sidelines at halftime; their initial placement is determined by the referee. In stadiums where both teams' benches are located on the same side of the field, the chain crew operates on the opposite sideline for the entire game.

Auxiliary chain crew

For professional and college football

College football

College football refers to American football played by teams of student athletes fielded by American universities, colleges, and military academies, or Canadian football played by teams of student athletes fielded by Canadian universities...

 games, an auxiliary chain crew operates on the opposite side of the field. Here, another "stick" and down indicator box is used so that players and officials can also look at the other side of the field to know where the first down line and the line of scrimmage is, respectively. 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 they lose possession. This indicator is only used for statistical purposes to calculate the distance of each drive. It looks similar to a "stick", but it has an arrow (or occasionally a large "X") that points in the direction the offensive team is going.

Members of the chain crew are usually picked by the offices of the home team instead of the league or conference that they play in.

Usage

All levels of football are believed to currently use the chain crew. One notable exception was the World Football League

World Football League

The World Football League was a short-lived gridiron football league that played in 1974 and part of 1975. Although the league's proclaimed ambition was to bring American football onto a worldwide stage, the farthest the WFL reached was placing a team – the Hawaiians – in Honolulu, Hawaii. The...

 of 1974 to 1975, which used a proprietary device called the "dicker-rod

Dicker-rod

The dicker-rod was used in the defunct World Football League in 1974 for the purpose of replacing the first down chains more commonly used in gridiron football organizations. The device was invented and patented by George Dicker of Orange County, California.The device was two and a half yards long...

," a 90-inch stick that allowed measurements to be made with one person instead of three. The dicker-rod never saw any usage outside the WFL.