Quarterback sack



In American football and Canadian football, a sack occurs when the quarterback is tackled or run out of bounds on or behind the line of scrimmage before he can throw a forward pass, or when the quarterback is tackled behind the line of scrimmage in the "pocket" and the intent of what he was going to do is unclear. This often occurs if the opposing team's defensive line, linebackers or defensive backs are able 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.

In the NFL, it is possible to record a sack for zero yards. The QB must pass the statistical line of scrimmage to avoid the sack. A sack is also credited when a defender causes the quarterback to fumble behind or at the line of scrimmage.

Yardage
In the NFL yards lost on the play are added as negative yardage to the team's passing totals; however, the quarterback's individual passing total stats remains unchanged. Previously, tackling a player behind the line of scrimmage resulted in a loss from that player's (passing) statistics, even if it were fairly obvious a rush play had been intended. NCAA continues to subtract sack yardage from individual rushing totals.

Rules
To be considered a sack the quarterback must intend to throw a forward pass. If the play is designed for the quarterback to rush (run) the ball, any loss is subtracted from the quarterback's rushing total. If the quarterback's intent is not obvious, statisticians use certain criteria, such as the offensive line blocking scheme, to decide. Unique situations where a loss reduces a quarterback's rushing total (not a sack) are "kneel downs" (used to run time off the game clock), and aborted plays, such as a fumbled snap that the quarterback falls on to maintain possession.

A player will receive credit for half of a sack when multiple players contribute to the sacking of a quarterback.

History
The term "Quarterback sack" was first coined by Hall of Fame defensive end Deacon Jones. Jones, who played in the NFL from 1961 to 1974, felt that a sack devastated the offense in the same way that a city was devastated when it was sacked.

However, the term "sack" was not widely used before ca. 1970; previously one would simply refer to a player's being tackled behind the line (of scrimmage), in so many words. The NFL only began to keep track of times a quarterback was sacked since 1963 and sacks by defensive players in 1982. Team records have been kept at least since the 1940s.

Individual records

 * NFL Single Season Sacks: 22.5 Michael Strahan, 2001


 * CFL Single Season Sacks: 26.5 James Parker, 1984


 * NFL Career Sacks: 200 Bruce Smith, 1985-2003


 * CFL Career Sacks: 157 Grover Covington, 1981-91


 * NFL Game Sacks: 7 Derrick Thomas, Nov. 11th, 1990


 * CFL Game Sacks: 5 by 11 players


 * NFL Sacks Rookie Season: 14.5 Jevon Kearse, 1999


 * Official in NFL since 1982