Linebacker

His central role on the field means he is in the best position to call defensive plays and direct shifts and changes based on what the offense is doing.

Historically, some of the most impactful defensive players, such as Pro Football Hall of Fame members Chuck Bednarik, Dick Butkus, Jack Lambert, Ray Lewis, Ray Nitschke, Mike Singletary, Brian Urlacher, and Lawrence Taylor, were linebackers.

Most sources claim coach Fielding H. Yost and center Germany Schulz of the Michigan invented the position.

For example, Percy Given of Georgetown is another center with a claim to the title "first linebacker," supposedly standing up behind the line well before Schulz in a game against Navy in 1902.

[9] In the East, Ernest Cozens of Penn was "one of the first of the roving centers,"[10] another archaic term for the position, supposedly coined by Hank Ketcham of Yale.

[12] Edgar Garbisch of Army was credited with developing the "roving center method" of playing defensive football in 1921.

[14] The middle or inside linebacker (MLB or ILB), sometimes called the "Mike" or "Mac",[15] is often referred to as the "quarterback of the defense".

Not only is the OLB responsible for outside containment and blitzing the QB, but they also have to perform pass coverage in the flats – sometimes called a drop.

[citation needed] The strongside linebacker (SLB) is often nicknamed the "Sam" for purposes of calling a blitz.

The outside linebacker's job is to cover the end to make sure a run does not escape and to watch the pass and protect from it.

The middle linebacker's job is to stop runs between the tackles and watch the entire field to see the play develop.

On pass plays, the linebackers' responsibilities vary based upon whether a man or zone coverage is called.

However, some zones will send the outside linebackers into the flats (area directly to the left and right of the hash marks, extending 4–5 yards downfield).

"Sam" is a common designation for strong outside linebacker, while the other position is usually called "Jack" and is often a hybrid DE/LB.

The focus of the 3–4 defensive line is to occupy offensive linemen thus freeing the linebackers to tackle the running back or to rush the passer or otherwise drop into pass coverage.

The primary responsibilities for both outside linebackers are typically to stop the run and rush the quarterback in passing situations, where they line in front of the tackles like true defensive ends.

Among inside linebackers, one is generally a run-stuffer who is better able to handle offensive linemen and stop running backs, while the other is often a smaller, faster player who excels in pass coverage.

Also, these inside line backers are often called on a blitz which is when no matter what the offense does, as soon as that ball is snapped they are shooting their gap and trying to get into the back field to make a play as fast as possible.

One of the outside linebackers is usually called into either blitz or pass coverage to make up for the missing defensive back.