Blocking (American football)

In American football, blocking or interference (or running interference) is a legal move occurring when one player obstructs another player's path with his body. The purpose of blocking is to prevent defensive players tackling the ball carrier, or to protect the quarterback while attempting to pass or hand-off the ball. Offensive linemen and fullbacks tend to do the most blocking, although wide receivers are often asked to help block on running plays and halfbacks may be asked to help block on passing plays, while tight ends performs pass block and run block if they are not running routes to receive catches.

As a general rule blocking is a push; one is not allowed to grasp someone or do any sort of pulling, and the hands must not be outside the line of each armpit, otherwise a holding penalty will be levied. Blocking is also not permitted beyond five yards from the line of scrimmage until the quarterback has handed-off the ball to a runner, or a receiver has touched the ball after it has been passed.

Outside sport, "running interference" is a metaphor that refers to a person's helping someone in the performance of a task without directly assisting in the task. Often this is done by attracting attention to oneself (so as to deflect attention from the other person) or throwing oneself into harm's way.

History

Interference remains strictly illegal in both rugby codes to today. The prohibition of interference in the rugby game stems from the game's strict enforcement of its offsides rule, which prohibited any player on the team with possession of the ball to loiter between the ball and the goal. At first, American players would find creative ways of aiding the runner by pretending to accidentally knock into defenders trying to tackle the runner. Interference developed out of a practice called "guarding;" run by Princeton, wherein a player ran at each side of the runner, but not in advance. When Walter Camp witnessed this tactic being employed against during a game he refereed between Harvard and Princeton in 1879, he was at first appalled, but the next year had adopted the blocking tactics for his own team at Yale. During the 1880s and 1890s, teams developed increasingly complex blocking tactics including the interlocking interference technique known as the Flying wedge or "V-trick formation", which was first employed by Richard Hodge at Princeton in 1884 in a game against Penn, however, Princeton put the tactic aside for the next 4 years, only to revive it again in 1888 to combat the three-time All-American Yale guard William "Pudge" Heffelfinger. Heffelfinger soon figured out how to break up the formation by leaping high in the air with his legs tucked under him, striking the V like a human cannonball. In 1892, during a game against Yale, a Harvard fan and student Lorin F. Deland first introduced the flying wedge as a kickoff play, in which two five man squads would line up about 25 yards behind the kicker, only to converge in a perfect flying wedge running downfield, where Harvard was able to trap the ball and hand it off to the speedy All-American Charley Brewer inside the wedge. Despite their effectiveness, the flying wedge, "V-trick formation" and other tactics which involved interlocking interference, were outlawed in 1905 through the efforts of the rule committee lead by Parke H. Davis, because of its contribution to serious injury. Non-interlocking interference remains a basic element of modern American football, with many complex schemes being developed and implemented over the years, including zone blocking and pass blocking.

See also

• Glossary of American football
• Shepherding, a similar tactic in Australian rules football
• Cut blocking