Linebacker Positions: Mike, Will and Sam Explained

The linebacker positions in a standard 4-3 defense are three: the Mike in the middle, the Sam on the strong side of the offensive formation and the Will on the weak side. The first letters are the code, M for middle, S for strong, W for weak. The Mike runs the defense and stops inside runs. The Sam plays over the tight end and takes on lead blockers. The Will, usually kept free of blockers by the linemen in front of him, chases the ball and makes tackles. A 3-4 defense uses four linebackers, two inside and two outside, and the outside pair spend most of their time rushing the passer. None of these names is in the Official Playing Rules of the National Football League or in the NCAA rule book. They are coaching terms, and they mean the same thing on Sundays and Saturdays.

Since 2008 the NFL has allowed one defender on the field to wear a helmet with a radio receiver in it, marked by a green sticker on the back. On most teams that helmet goes to the middle linebacker. He hears the call from the sideline, repeats it to ten teammates, and is the last defender to stop talking before the ball is snapped. That is the Mike.

The three linebacker positions: Mike, Will and Sam

Linebackers are the second level of the defense. They stand up, three to five yards behind the linemen, and they are the only defenders asked to do all three of the sport's defensive jobs on a regular basis: stop the run, cover receivers and rush the quarterback.

Name	Stands for	Where he lines up	First job against the run	First job against the pass
Mike	Middle	Behind the defensive tackles, over the ball	Fills the inside gaps	Covers the middle of the field
Sam	Strong side	Over or near the tight end	Takes on the tight end or the lead blocker	Covers the tight end or the flat
Will	Weak side	Behind the linemen, away from the tight end	Pursues the ball from the back side	Covers a running back or a short zone

The table is the 4-3 version, three linebackers behind four linemen, and it is the one every fan learns first. It is also a simplification. Who is strong and who is weak changes play by play, the Sam may be on the bench for most of the game, and a 3-4 team uses some of the same names for different jobs.

The names were chosen for the huddle. A coach who says "strong-side linebacker" in a meeting needs a shorter word on a loud field, and a first name that starts with the right letter does it. Some staffs say Mac or Mack for the middle. A few have their own. The convention is decades old and has outlasted every attempt to replace it, because nothing shorter has been found.

NFL rules allow linebackers to wear numbers from 0 through 59 and 90 through 99. The 50s are the traditional home of the position, though since the league loosened its numbering in 2021 a linebacker in a single digit is no longer a surprise.

Strong side and weak side: how the offense decides where Sam and Will stand

The defense does not choose its strong side. The offense does.

By the oldest definition the strong side is the side of the formation with the tight end on it. A tight end is an extra blocker, so that side has one more gap to defend and one more body to move people. The Sam goes there. The Will goes to the other side.

That worked cleanly when every offense lined up with one tight end and two backs. It works less cleanly now. Offenses use two tight ends, or none, or put three receivers to one side and the tight end alone on the other. So defenses carry more than one rule for strength.

Run strength is set to the tight end, or to the side with more blockers.

Passing strength is set to the side with more eligible receivers. Three receivers to the left and one to the right means the passing strength is left, whichever side the tight end is on.

When the two disagree, the game plan says which wins. When the formation is perfectly balanced, there is a tiebreaker: the wide side of the field, or the quarterback's throwing arm, or simply the defense's left. The linebacker making the call shouts a single word that means "strength left" or "strength right," and the front and the coverage both set from it.

Field and boundary

The college game adds a wrinkle. College hash marks are 40 feet apart, against 18 feet 6 inches in the NFL, so a ball spotted on a hash leaves a much wider side and a much shorter side. Many college defenses skip strong and weak altogether and assign linebackers to the field, the wide side, and the boundary, the short side. The field linebacker has to cover ground. The boundary linebacker can be bigger and slower because the sideline helps him.

Flipping

Some teams move their linebackers every time the strength changes, so the Sam is always on the tight end. Others keep a left and a right linebacker and teach both men both jobs. Flipping keeps each player in the role he is built for. It also gives the offense a tool, because a tight end who shifts across the formation just before the snap can force two linebackers to run past each other with the play clock at three seconds.

What is a Mike linebacker: the green dot, the front and the deep middle

Start with what he does before anyone moves.

• 1994Year quarterbacks first got the radio
• 2008Year one defender was allowed it
• 15Second on the play clock when it cuts off
• 1Live defensive radio helmets on the field at once

NFL coach-to-player communication rules. Major college football adopted a similar one-helmet system for the 2024 season.

The helmet radio is one-way. The coordinator talks, the player listens, and the line goes dead when the play clock reaches 15 seconds or the ball is snapped, whichever comes first. Only one defender on the field may wear a live helmet, marked with a green dot, and a team names a backup in case he leaves the game. It does not have to be the Mike. Some teams give it to a safety. Most give it to the one defender who rarely comes off the field and stands in the middle of everybody.

After the call comes the adjusting. The Mike identifies the offense's strength and announces it. He sets the defensive line, telling the tackles which way to shade. If the offense shifts or sends a man in motion, he re-sets it. If the offense comes out in a formation the call was not designed for, he has the authority on most teams to check to something else. A good middle linebacker is doing the same pre-snap work as the quarterback across from him, with less time and more noise.

Against the run

The Mike's gap depends on the front, but it is nearly always inside, an A gap or a B gap, the spaces on either side of the guards. The linemen in front of him are aligned to cover some gaps and leave others open, and the open ones belong to the linebackers. How those letters and alignments work is set out in our guide to the gaps and techniques of the defensive line.

His opponent is usually a guard or a center coming off a double team to block him, a man who outweighs him by 70 pounds. The Mike's craft is to meet that block with force, on the correct shoulder, without being driven backward, and still get off it to make the tackle.

Against the pass

In most zone coverages the Mike drops to the middle hook, a short zone between the hash marks eight to twelve yards deep, and reads the quarterback's eyes.

One coverage asks far more. In the Tampa 2, the version of Cover 2 that Tony Dungy and Monte Kiffin ran in Tampa Bay in the late 1990s, the middle linebacker turns and runs down the middle of the field to cover the deep seam between the two safeties. Dungy has traced the idea to the Pittsburgh defenses he played on in the 1970s, where Jack Lambert did the same thing. It demands a linebacker who can run with a tight end twenty-five yards downfield. Brian Urlacher, a college safety who became Chicago's middle linebacker and the league's Defensive Player of the Year for 2005, was the model. The coverage itself is described in our explainer on the Cover 2 defense.

The Will: the run-and-chase linebacker who leads the team in tackles

The weak-side linebacker has the best job on the defense, and the defensive front is arranged to give it to him.

Away from the tight end there is one fewer blocker. In the most common four-man fronts the defensive tackle on that side lines up on the guard's outside shoulder and the end plays outside the tackle, so both of the offensive linemen nearest the Will have someone to block before they can think about him. He is "covered up." Nobody comes off the line to hit him cleanly, and he is free to read the play and run.

So the Will is built for speed over size. He is frequently the lightest linebacker on the roster and the best athlete of the three. On a run toward him he fills his gap. On a run away from him, which is where the tight end's side sends most of them, he pursues from behind the play, staying a step behind the ball so that he is in position if the runner cuts back. Cutback runs are the Will's to stop. A weak-side linebacker who chases too fast and overruns the ball gives up the longest runs a defense allows.

He ends up near the football more than anyone, and the tackle column reflects it. Derrick Brooks played the position for Tampa Bay for 14 seasons, was Defensive Player of the Year for 2002 and went into the Pro Football Hall of Fame in 2014.

A caution about tackle totals

Tackles are not an official NFL statistic. They are recorded in the press box by the home team's statistics crew as the game is played, crews differ in how freely they hand out assists, and many coaching staffs recount the totals from film on Monday and publish their own. A linebacker can be credited with noticeably different season totals by his own team and by the league's website.

The numbers still say something. A linebacker who leads his team by a wide margin is around the ball. But comparing one player's tackles to another's across teams, or across eras, is comparing two different counts, and this page quotes none for that reason.

The Will in coverage

When the defense goes to five defensive backs, the Will is one of the two linebackers who stay. That fact has changed the position more than any other. The modern Will is chosen first for whether he can run with a running back on a wheel route or carry a slot receiver through a zone, and second for whether he can take on a guard.

The Sam: the tight end, the lead blocker and the first man off the field

The Sam's job is the most physical of the three and the least rewarded.

He lines up on the tight end's side, often directly over him and sometimes on the line of scrimmage itself. On a run to that side he has a blocker on him at once. His assignment is to hold the point: keep the tight end from pushing him back or turning him, and keep the ball from getting outside.

When the offense adds a fullback, the Sam is frequently the man who meets him in the hole. He does not have to make the tackle. He has to hit the lead blocker hard enough, and on the right side, that the running back has to change course into a teammate. The blocker's half of that collision is described in our guide to the fullback and the running back.

In coverage the Sam draws the tight end, either man-to-man or by dropping to the curl or the flat on that side. In some schemes he is also a part-time pass rusher. Von Miller, drafted second overall in 2011, spent his first seasons in Denver listed as a strong-side linebacker in a 4-3: he played over the tight end on early downs and moved to the edge to rush on passing downs.

Why the Sam is disappearing

Every part of the job description above depends on the offense using a tight end as a blocker and a fullback as a lead. Offenses do both far less than they did. Against three wide receivers there is no lead blocker to take on and the tight end may be split out as a receiver, so the defense takes the Sam off and sends in a cornerback.

In the nickel era the starting Sam on many NFL teams has played fewer than half the defensive snaps. Some rosters do not carry a true one. The position survives in short-yardage and goal-line groupings and against teams that still run from heavy sets, and it is the clearest case of an offense's choices deleting a defensive job. The offensive side of that arithmetic is in our guide to personnel groupings such as 11 and 12.

Inside linebacker vs outside linebacker in a 3-4

Take a lineman out and add a linebacker, and the names shift.

A 3-4 has two inside linebackers standing behind three linemen and two outside linebackers on the ends of the line. The inside pair split what the Mike does alone in a 4-3. The outside pair are, on most snaps, pass rushers who happen to stand up.

Spot	Names used for it	The job
Strong inside	Mike, Ted, Buck	Takes on a guard, plugs the inside run, often makes the calls
Weak inside	Will, Mo, Mack, Jack	The freer of the two; runs to the ball and covers
Strong outside	Sam	Plays over the tight end, holds the edge, rushes or drops
Weak outside	Jack, Rush, Buck, Will	The primary pass rusher

The second column is a mess, and it is an honest one. There is no league glossary. Pittsburgh has long called its inside linebackers the Buck and the Mack. Nick Saban's defenses use Jack for the weak-side rusher, and other staffs use Jack for an inside linebacker. Buck is an inside run stopper in one building and a stand-up end in another. A player who changes teams may keep his job and lose his name, or the reverse.

What matters is the split. The strong inside linebacker is the thumper. With only three linemen in front, a guard is often free to come straight at him, and he has to take that block on so his partner does not. The weak inside linebacker is protected and plays more like a 4-3 Will.

The outside pair are really ends

A 3-4 outside linebacker rushes the passer far more often than he covers. He lines up outside the offensive tackle, he is judged on sacks, and when the defense goes to nickel he usually puts a hand on the ground next to a defensive tackle and becomes, to the eye, a defensive end.

That is the overlap that produced a separate label for the role. The stance, the moves and the way offenses block these players belong in our guide to the edge rusher, and when this page says "linebacker" from here on it means the ones who play off the ball. How the two fronts compare as whole systems is in our guide to 4-3 and 3-4 defenses.

Run fits: reading the guards, scraping, spilling and filling

A linebacker cannot wait to see where the ball goes. By the time the running back has it, the blockers have arrived. He has to read something that moves earlier, and in most systems that something is the guard.

1. 1KeyHis eyes are on the guard nearest him, with the backfield in his peripheral vision.
2. 2Read stepOn the snap he takes a short step in place, or slightly forward, and does not commit.
3. 3DiagnoseThe guard's first movement tells him the play: firing out, pulling, blocking down or setting to pass.
4. 4FitHe attacks the gap the call gave him, downhill, before the blocker assigned to him gets there.
5. 5LeverageHe takes on any blocker with the shoulder that keeps the ball going where the defense wants it.
6. 6FinishHe sheds, tackles or forces the cutback to a teammate.

A general teaching sequence. Keys differ by scheme, and some defenses teach linebackers to read the running back's first steps as well as the linemen.

What the guard tells him

A guard who fires straight out at the linebacker means a run right at him. A guard who stands up and retreats, "high hat" in the jargon, means pass, and the linebacker drops. A guard who blocks down on the defensive tackle next to him means something is coming around behind, a trap or a pulling lineman from the other side. A guard who pulls is the loudest key of all, because the offense is taking a blocker to the point of attack, and the linebacker is taught to follow him there.

This is the mechanism that play action exploits. The offensive line shows a run for one beat, the linebackers take their downhill steps, and the ball is thrown into the space they just left. Run-pass options go a step further and let the quarterback read one specific linebacker after the snap: if he steps up, throw behind him, and if he drops, hand off. That linebacker is wrong by design. Both concepts are laid out in our explainers on play action and the RPO.

Scrape, spill, fill

Three verbs cover most of what a linebacker does once he has read run.

To fill is to step into a gap directly in front of him and meet the play there. The Mike on an inside run is filling.

To scrape is to run laterally behind the defensive line, staying just behind the ball, and then turn upfield through the first open gap. A linebacker scrapes over the top of his linemen on a run to the outside. The skill is patience. Go too early and the back cuts behind him; go too flat and he is caught in the wash of bodies.

To spill is to take on a lead blocker or a puller by attacking his inside half, so that the runner cannot go inside and has to bounce toward the sideline. A spill only works if a teammate is scraping over the top to meet the runner there. Defenses that spill everything are betting on team speed. Defenses that instead turn every block back inside are betting on having bigger people in the middle.

A run fit is the complete assignment: every gap accounted for by a named defender after all the pulling and leading is done. One linebacker fitting the wrong gap is the difference between a two-yard gain and a forty-yard one. It is rarely visible on the broadcast angle.

Pass coverage: hook and curl zones, walling off crossers and matching backs in man

On a passing down the linebackers are responsible for the part of the field offenses attack most: the short and intermediate middle.

In zone, the area underneath the deep defenders is divided into strips. The flat is the outside strip near the sideline. The curl zone is inside that, roughly over the offensive tackle and slot. The hook zones are in the middle, on either side of the ball. A linebacker assigned to a hook or a curl drops to a depth of ten or twelve yards with his head turned to the quarterback, and breaks on the throw. He is guarding grass, and he is expected to make the quarterback throw the ball over him or in front of him.

The modern versions are less passive. In pattern-matching zones, a linebacker starts in a zone drop and converts to man coverage on whichever receiver enters his area, according to rules about which route he sees first. It is the hardest thing the position is asked to learn.

Walling off crossers

The route that beats zone is the crosser, a receiver running across the field at linebacker depth through the seams between zones. A linebacker's answer is to wall it off: step into the receiver's path, make him go around, and hand him to the next defender. Within five yards of the line of scrimmage he may make contact. Beyond five yards in the NFL he may not hold up or reroute a receiver while the quarterback is in the pocket with the ball, the limit explained in our guide to the illegal contact penalty. College rules are looser on contact before the pass is thrown, which is one reason college linebackers look more physical in coverage.

In man coverage with a single deep safety, one linebacker is often left without a man. He becomes the "rat" or "hole" player, sitting in the short middle to cut off crossing routes and to help on whoever comes his way.

Man coverage on backs and tight ends

This is where offenses hunt. A linebacker in man coverage has the running back or the tight end, and offensive coordinators spend the week finding the formation that puts their fastest back on the defense's slowest linebacker with no help nearby. A back motioned out wide to see who follows him is a test: if a linebacker walks out, it is man, and it is a matchup the quarterback likes.

Defenses protect their linebackers with calls that let two defenders trade assignments depending on which way the receivers release, and by substituting a safety for a linebacker on passing downs. The trade between the two families of coverage is the subject of our explainer on man and zone coverage.

The linebacker as a rusher: A-gap pressure looks and the green dog

"Dog" is one of the oldest words in defensive football. Broadcasters of the 1950s and 1960s called a rushing linebacker a red dog, and many staffs still say dog for a linebacker pressure and keep blitz for one that includes a defensive back, though usage varies from building to building.

The inside linebacker's shortest path to the quarterback is the A gap, straight past the center. In the look that Mike Zimmer made a trademark in Cincinnati and Minnesota, both inside linebackers walk up before the snap and stand in the two A gaps, one on each side of the center. The offense now has a problem of arithmetic. The center can block one of them. The other belongs to a guard, who then cannot help outside, or to the running back, who has to step up into a charging 240-pound man.

The pressure is in the uncertainty. From that alignment both linebackers can come, or one, or neither. They can drop out at the snap into the short zones they would have covered anyway, having forced the offensive line to squeeze inside and leave the edges one-on-one. The protection has to be set for the worst case every time.

A cross dog sends both, with one going first and the other looping behind him, the linebacker version of a line stunt.

The green dog

A green dog is a rush that is not called in the huddle. A linebacker has a running back in man coverage. The ball is snapped, and the back stays in to block. The linebacker now has nobody to cover, so by rule he rushes, usually right at the back he was assigned to.

It is a tidy piece of design. The offense kept an extra blocker in, and the defense added an extra rusher in response without risking anything in coverage. The danger is the delayed release: a back who blocks for a count and then slips out on a screen or a checkdown behind a linebacker who has just committed to the rush. Reading the difference between a back who is blocking and one who is pretending to is most of the skill. The fuller catalogue of pressures is in our explainer on blitz packages.

Why the quarterback points at a linebacker and calls him the Mike

Field microphones pick it up before most passing plays. The quarterback points across the line and shouts a jersey number followed by "is the Mike."

He is not introducing the middle linebacker. He is setting the count for his pass protection.

1. 1Count the rushersThe offense identifies the down linemen and the linebackers who could come.
2. 2Declare the MikeThe quarterback or the center names one linebacker. He becomes the reference point for the line.
3. 3Assign the lineThe five linemen are responsible for the down linemen plus the declared Mike if he rushes.
4. 4Assign the backThe running back takes the next most dangerous rusher outside that count.
5. 5Identify the free manAny rusher beyond those six is unblocked by design. The quarterback must throw before he arrives.
6. 6Defense movesIf linebackers shift or a safety walks down, the quarterback may re-declare and the count resets.

A simplified description of a standard six-man protection. Terminology and who makes the declaration vary by team.

The declared Mike is whoever makes the arithmetic work. Against a normal look it is the real middle linebacker. Against a pressure look it may be a weak-side linebacker, or a safety standing in the box. The point is that all five linemen, the back and the quarterback agree on who is blocked and who is not.

Defenses attack the declaration. A linebacker who has been named walks away; another creeps up on the other side; a safety rotates down at the last second. The aim is to get the quarterback to count wrong, or to run the play clock down while he fixes it. That is the reason the Mike on defense and the quarterback can be seen pointing and shouting at each other for ten seconds before some snaps. They are arguing about the same number.

The quarterback's part of that exchange, and the other checks he makes at the line, are in our guide to what a quarterback does. The center's part, since he often makes the call himself, is in our guide to the offensive line.

How the passing game shrank the linebacker position

For most of the sport's history a defense's base personnel was its real personnel. That is no longer true.

3-4 base4linebackers

4-3 base3linebackers

Nickel, five defensive backs2linebackers

Dime, six defensive backs1linebackers

Nominal positions in common personnel groupings. A 3-4 team's nickel package may still list four linebackers, but the outside two are rushing as ends.

Show the numbers

Linebackers on the field, by defensive package

Item	Value
3-4 base	4linebackers
4-3 base	3linebackers
Nickel, five defensive backs	2linebackers
Dime, six defensive backs	1linebackers

Offenses made three wide receivers their standard grouping, and defenses responded by making nickel theirs. In practical terms the third linebacker became a part-time player and the fifth defensive back became a starter, a change traced in our explainer on nickel and dime defense. A team that lists three starting linebackers will commonly have only two on the field for most of a game.

The two who remain have changed shape. The run-stopping middle linebacker of the 1990s and early 2000s was chosen to take on a fullback in the hole and often weighed 245 or 250 pounds. His successor is asked to cover a slot receiver for three seconds, and teams have accepted a player fifteen or twenty pounds lighter to get it. Those weights are scouting generalities and exceptions are easy to find. The direction is not in dispute.

The hybrid

The next step was to stop calling the player a linebacker. In 2014 Arizona drafted Deone Bucannon, a safety, in the first round and then played him at inside linebacker at a little over 210 pounds, a role the team called the moneybacker. Others followed with their own names: dollar, star, rover, big nickel. The idea in each case is a defender with a safety's speed standing where a linebacker would, on the bet that covering a tight end is now worth more than taking on a guard.

Offenses have an answer, and it is the oldest one. Put a second tight end on the field, run the ball at the 210-pound man and make him prove he can hold up. Whether a team can do that for four quarters decides how small the defense can afford to be. Where the hybrid ends and an ordinary safety begins is taken up in our guide to the free safety and the strong safety.

Our judgment is that the position has been narrowed more than diminished. There are fewer linebackers on the field, and the ones left are asked to do more kinds of work than the men who played the position at its most celebrated.

The lineage: Bill George to Ray Lewis

The middle linebacker was invented by a player getting tired of being in the way.

Through the early 1950s the standard NFL defense had five linemen, with a middle guard directly over the center. Bill George played that spot for the Chicago Bears. In a 1954 game against Philadelphia he found that hitting the center on every pass play accomplished little while short passes were being completed just behind him. So he stopped putting his hand down, took a couple of steps back and started knocking those passes away. Five linemen became four. The man in the middle now stood up. George went to eight consecutive Pro Bowls and entered the Hall of Fame in 1974.

Others were arriving at the same place. Tom Landry, then running the New York Giants defense, built his 4-3 around Sam Huff, and in 1960 a CBS documentary, "The Violent World of Sam Huff," put a microphone on him and made the middle linebacker a public figure. Joe Schmidt in Detroit and Ray Nitschke in Green Bay defined the job in the same years.

Player	Team and years	What he added to the position
Bill George	Chicago Bears, 1952-65	Stood up from middle guard and created the role
Dick Butkus	Chicago Bears, 1965-73	The standard for hitting and for range sideline to sideline
Jack Lambert	Pittsburgh Steelers, 1974-84	A lighter, faster Mike who covered the deep middle
Mike Singletary	Chicago Bears, 1981-92	The signal-caller at the center of the 46 defense
Ray Lewis	Baltimore Ravens, 1996-2012	Speed and coverage in a pass-first era

Dick Butkus was the third player taken in the 1965 draft, out of Illinois, and for nine seasons he was the most feared tackler in the sport on Bears teams that seldom won. Knee injuries ended his career early. He was inducted in 1979.

Jack Lambert was listed at about 220 pounds, light for a middle linebacker even then. Pittsburgh used that. Behind a front four that kept blockers off him he ran to the ball, and in passing situations he dropped far deeper than middle linebackers had before. He was Defensive Player of the Year for 1976 and a Hall of Famer in 1990.

Mike Singletary was the Mike in Buddy Ryan's 46 defense, the eight-man front named for safety Doug Plank's jersey number, and was responsible for getting the 1985 Bears lined up in a scheme with an unusual number of checks. He was Defensive Player of the Year for 1985 and again for 1988.

Ray Lewis came into the league in 1996, when the position was already being asked to cover more than to collide. He won the same award for 2000 and 2003, was the Most Valuable Player of Super Bowl XXXV, and played 17 seasons for one franchise. He was inducted in 2018.

Three of the five played for Chicago, which is why the Bears are spoken of as the middle linebacker's team. The through line is less about one city than about one requirement. Each man was the defender who had to know what all ten others were doing. The helmet with the green dot has made that job audible, and it is still the reason the Mike exists. More on how the other twenty-one fit around him is collected in our American football section.