Linebacker (LB) is a playing position in gridiron football. Linebackers are members of the defensive team, and line up three to five yards behind the line of scrimmage and the defensive linemen. They are the "middle ground" of defenders, playing closer to the line of scrimmage than the defensive backs (secondary), but farther back than the defensive linemen.
In white jerseys, Lance Briggs (#55) and Brian Urlacher (#54) of the Chicago Bears, are positioned as linebackers on Lambeau Field in 2011.
Chuck Bednarik of the Philadelphia Eagles, a first round draft selection in the 1949 NFL Draft and member of the Pro Football Hall of Fame, is considered one of the hardest hitting and best linebackers in NFL history; his November 20, 1960 tackle of Frank Gifford, a New York Giants running back, is known simply as "The Hit" and is considered one of the hardest hits in the league's history.