Title: Linebacker
Content:   A linebacker (LB or backer) is a playing position in gridiron football. Linebackers are members of the defensive team, and line up approximately three to five yards (4 m) behind the line of scrimmage and behind the defensive linemen. They represent the "middle ground" of defenders, playing closer to the line of scrimmage than do the defensive backs (or secondary), but further back than do the defensive linemen. As such, linebackers play a hybrid role and are often the most versatile players on the defensive side of the ball; they can be asked to play roles similar to either a defensive lineman (such as stopping the runner on a running play) or a defensive back (such as dropping back into pass coverage). How a linebacker plays their position depends greatly on the defensive alignment, the philosophy of the coaching staff, and the particular play the offense may call. Within 
Title: Linebacker
Content:  The strongside linebacker (SLB) is often nicknamed the "Sam" for purposes of calling a blitz. Since the strong side of the offensive team is the side on which the tight end lines up, or whichever side contains the most personnel, the strongside linebacker usually lines up across from the tight end. Often the strongside linebacker will be called upon to tackle the running back on a play because the back will be following the tight end's block. He is most often the strongest linebacker; at the least he possesses the ability to withstand, shed, and fight off blocks from a tight end or fullback blocking the backside of a pass play. The linebacker should also have strong safety abilities in pass situation to cover the tight end in man on man situations. He should also have considerable quickness to read and get into coverage in zone situations. The strongside linebacker is also commonly known as the left outside linebacker (LOLB).
Title: Linebacker
Content:  The middle or inside linebacker (MLB or ILB), sometimes called the "Mike" or "Mack", is often referred to as the "quarterback of the defense". Often it is the middle linebacker who receives the defensive play calls from the sideline and relays that play to the rest of the team, and in the NFL he is usually the defensive player with the electronic sideline communicator. A jack-of-all-trades, the middle linebacker can be asked to blitz (though they often blitz less than the outside linebacker), cover, spy the quarterback, or even have a deep middle-of-the-field responsibility in the Tampa 2 defense. In standard defenses, middle linebackers commonly lead the team 
Title: Canadian football
Content: Middle linebacker: Starts the play across from the centre, about 3-4 yards away. Generally the leader of the defence. Calls plays for linemen and linebackers. ; Weak-side linebacker: Lines up on the short side of the field, and can drop back into pass coverage, or contain a run. ; Strong-side linebacker: Lines up on the long side of the field, and usually focuses on stopping the runner. 
Title: Linebacker
Content:  line backers sometimes are considered to be pass players before they are run players. But that depends on where they are lined up, if they are outside of the box of the defense then they will be pass first players, but if they play inside the box lined up behind the defensive end then they are typically a run player. One of the outside linebackers is usually called into either blitz or pass coverage to make up for the missing DB. In the NFL and college football, this alignment is used mainly in short yardage situations or near the goal line. It is commonly used in high school football.
Title: Linebacker
Content:  linebacking corps, they are often divided into middle linebackers, sometimes called inside linebackers, and outside linebackers. The middle linebacker, often called the "Mike", is frequently the "quarterback of the defense". 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. Outside linebackers are often in a unique position to blitz, a type of defensive maneuver where the player rushes unexpectedly into the offensive backfield in an attempt to disrupt a running play or sack the quarterback on passing plays. Besides "Mike", other nicknames such as "Sam", "Will", or "Jack", among others, are commonly used to refer to various linebacking roles, to ease communication in play-calling. Historically, some of the most impactful defensive players, such as Pro Football Hall of Fame members Mike Singletary, Lawrence Taylor, and Ray Lewis, were linebackers.
Title: American football strategy
Content: Outside linebackers: The outside linebackers ("OLB") set up on the outside portion of the line of scrimmage. They are often used to rush the quarterback. OLBs tend to be the fastest and most agile linebackers on the defense. ; Inside linebackers: Inside linebackers ("ILB"), sometimes also referred to as middle linebackers ("MLB") set up on the inside portion of the line of scrimmage. ILBs tend to be the biggest and strongest linebackers on the defense. Linebackers stand behind the defensive linemen or set themselves up on the line of scrimmage. Depending on the type of defensive strategy being used, a linebacker's responsibilities can include helping to stop the run, rushing the quarterback, or dropping back in pass protection.
Title: American football
Content:  middle linebackers (MLB) and outside linebackers (OLB). Linebackers are the defensive leaders and call the defensive plays. Their diverse roles include defending the run, pressuring the quarterback, and guarding backs, wide receivers and tight ends in the passing game. The defensive backfield, often called the secondary, consists of cornerbacks (CB) and safeties (S). Safeties are themselves divided into free safeties (FS) and strong safeties (SS). Cornerbacks line up outside the defensive formation, typically opposite a receiver to be able to cover them. Safeties line up between the cornerbacks but farther back in the secondary. Safeties are the last line of defense and are responsible for stopping deep passing plays as well as running plays.
Title: Linebacker
Content:  The weakside linebacker (WLB), or the "Will" in 4–3 defense, sometimes called the backside linebacker, or "Buck", as well as other names like Jack or Bandit, must be the fastest of the three, because he is often the one called into pass coverage. He is also usually chasing the play from the backside, so the ability to maneuver through traffic is a necessity for the Will. The Will usually aligns off the line of scrimmage at the same depth as Mike. Because of his position on the weakside, the Will does not often have to face large interior linemen one on one unless one is pulling. In coverage, the Will often covers the back that attacks his side of the field first in man coverage, while covering the weak flat in Texas Loop or hooks/curl areas in zone coverage. The weakside linebacker is also commonly known as the right outside linebacker (ROLB).
Title: Linebacker
Content:  The outside linebacker (OLB), sometimes called the "Buck, Sam, and Rebel" is usually responsible for outside containment. This includes the strongside and weakside designations below. They are also responsible for blitzing the quarterback. 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. Outside linebackers pass coverages covers quick slants outside, in curls in the flats. The "flats" are the edge of the field closest to the sideline, from the line of scrimmage down about ten yards.

Question: What sport does linebacker play?
Answer: American football.
gridiron football.
🏈.
football.
American rules football.