Defensive Line Positions: Tackle, End and Nose Explained
The defensive line positions in the NFL, from nose tackle to defensive end: where each lines up, the gaps and technique numbers, and the job on run and pass.
By CricketTaken EditorialPublished NFL Positions & Schemes26 min read
- Linemen in a 4-3 front
- 4
- Linemen in a 3-4 front
- 3
- Technique numbers
- 0 to 9
- Defensive offside penalty
- 5 yards
The defensive line positions in the NFL are the defensive tackle, the defensive end and the nose tackle. A four-man line plays two tackles inside, across from the guards and the center, with an end on either side of them across from the offensive tackles. A three-man line plays one nose tackle over the center and two ends lined up on the offensive tackles. Tackles stop runs up the middle and push the pocket back into the quarterback's lap. Ends keep the ball from getting outside and rush the passer from the corner. Coaches then get more exact, with letters for the gaps between blockers and numbers from 0 to 9, called techniques, for the precise spot each lineman occupies. None of that vocabulary appears in the Official Playing Rules of the National Football League, which ask only that a defender stay out of the neutral zone until the snap. It is coaching language, and it is the same language on Saturdays under the NCAA rule book.
Where one lineman puts his hand down can decide a game. On January 11, 1970, at Tulane Stadium in New Orleans, Kansas City coach Hank Stram spent Super Bowl IV parking a very large man, Curley Culp on some snaps and Buck Buchanan on others, directly on the nose of Minnesota center Mick Tingelhoff. The Vikings' running game depended on a quick, light center getting out to block linebackers. He never got out. Kansas City won 23-7, and the alignment of one defensive lineman did as much to settle it as anything the quarterbacks did.
The defensive line positions from the inside out
A defensive lineman is, by convention, a defender who starts the play with a hand on the ground within a yard or so of the ball. That stance is the working definition. A linebacker stands up; a lineman is down.
| Position | Usual front | Where he lines up | Against the run | Against the pass |
|---|---|---|---|---|
| Nose tackle | 3-4, and one tackle spot in a 4-3 | Over the center or on his shoulder | Holds the middle against two blockers | Drives the center into the quarterback |
| Three-technique tackle | 4-3 | Outside shoulder of a guard | Shoots the B gap to make the play behind the line | The main interior rusher |
| Strong-side end | 4-3 | Outside the tackle or over the tight end | Sets the edge and turns the runner back inside | Power rush on the right tackle |
| Weak-side end | 4-3 | Outside the tackle on the side with no tight end | Chases plays down from behind | Speed rush on the left tackle |
| Five-technique end | 3-4 | Outside shoulder of the offensive tackle | Controls two gaps and occupies blockers | Pushes the pocket more than he wins the corner |
The table hides an awkward truth about the names. "Defensive end" means two different players depending on the front. In a four-man line the end is the lean, long-armed athlete who is paid to hit quarterbacks. In a three-man line the end is a 300-pound run stopper whose job resembles a tackle's, and the pass rushing passes to the outside linebackers standing next to him. A fan who reads "DE" on a depth chart and expects sacks from a 3-4 end will wait a long time. How the two fronts divide the labor is the subject of our comparison of the 4-3 and the 3-4 defense.
Depth charts list a left end and a right end, a left tackle and a right tackle. Those names are fixed to the defense's own left and right. Many teams ignore them once the game starts and flip their linemen according to where the offense puts its tight end, which is why the terms that matter on the field are strong side and weak side.
NFL numbering gives the group away. Under the league's numbering rule, defensive linemen wear 50 through 79 or 90 through 99.
Why the line comes first
Every defensive call starts from the front. The coverage behind it can be disguised and rotated, but the linemen have to be somewhere when the ball is snapped, and each of them has to know which piece of the line belongs to him. The system for saying so is the gap.
A gap, B gap, C gap: the arithmetic every run defense starts with
Stand behind an offensive line and look at the spaces between the blockers. Those spaces are the gaps, and they are lettered from the center outward. The A gap is between the center and a guard. The B gap is between a guard and a tackle. The C gap is outside the tackle, between him and a tight end if there is one. The D gap is outside the tight end. Each letter exists twice, once on either side of the ball, so coaches speak of the strong-side A gap or the weak-side B gap.
A running back can only carry the ball through a gap. That is the entire logic of run defense: put one defender in every gap and there is nowhere to go.
The chart explains most of what a defense does before the snap. Against a formation with one tight end there are seven gaps, so a defense with four linemen and three linebackers has a man for each. Add a second tight end and the defense needs an eighth body near the line, usually a safety walking down. Swap a tight end for a third wide receiver, and the offense has removed a gap, so the defense can remove a linebacker and bring on a defensive back.
Motion changes the count after everyone is set. A fullback who leads through the hole creates an extra gap at the point where he arrives. A pulling guard does something subtler: he deletes a gap on the side he leaves and adds one on the side he runs to, which is what makes power, counter and the other gap-scheme runs so hard to fit. The defense has to move its gap assignments at the speed of the pull.
One gap or two
There are two philosophies about how a lineman should own his space.
A one-gap lineman lines up on a blocker's shoulder, attacks the gap in front of him on the snap and tries to get into the backfield. It is aggressive, simple to teach and it suits quicker, lighter players. Most four-man lines are one-gap fronts.
A two-gap lineman lines up nose to nose with a blocker, strikes him, holds his ground and controls the gap on either side, falling off toward whichever one the runner chooses. It is slower and it produces few highlights. What it buys is numbers. If three linemen can account for six gaps between them, the linebackers behind them are left over to run to the ball.
Neither is correct. The two-gap approach asks for rarer bodies; the one-gap approach asks every defender to be right every time, because a lineman who shoots the wrong gap has left a lane with nobody in it.
Defensive line techniques explained: the numbers from 0 to 9
Gaps say what a lineman is responsible for. Techniques say where he stands. The numbering most of the sport uses is usually credited to Bum Phillips, who is said to have worked it out as a Texas high school coach, and to Paul "Bear" Bryant, who spread it after Phillips joined his staff at Texas A&M in the 1950s. Accounts differ on how to divide the credit between the two men, and the detail of the story varies with the teller.
The principle is that even numbers put a defender head-up on a blocker and odd numbers put him on a shoulder, counting outward from the ball.
| Technique | Alignment | Gap it usually points to |
|---|---|---|
| 0 | Head-up on the center | Both A gaps |
| 1 | Shoulder of the center | A gap |
| 2i | Inside shoulder of the guard | A gap |
| 2 | Head-up on the guard | A and B gaps |
| 3 | Outside shoulder of the guard | B gap |
| 4i | Inside shoulder of the tackle | B gap |
| 4 | Head-up on the tackle | B and C gaps |
| 5 | Outside shoulder of the tackle | C gap |
| 7 | Inside shoulder of the tight end | C gap |
| 6 | Head-up on the tight end | C and D gaps |
| 9 | Outside shoulder of the tight end | D gap |
Two wrinkles catch people. The first is the 7, which sits inside the 6 and so breaks the counting order. It is a quirk the convention has kept rather than renumbered. The second is the letter "i," used for inside shades on the guard and the tackle that the plain numbers do not cover.
The language then turned alignments into nouns. A "three-tech" is a tackle who plays the three-technique. A "five-tech" is an end who plays outside the tackle. A "shade" is any alignment on a shoulder rather than head-up, and a "shade nose" is a nose tackle in a 1. Scouting reports use the terms as body types: a prospect is "a three-tech only" or "can play anywhere from the 1 to the 5."
One caution. This is a convention and not a standard. Some staffs number the tight end alignments differently, some use an 8 for a player lined up wide of everything, and the "wide 9" of recent years is a pass-rush alignment a yard or more outside where the original 9 stood. The numbers from 0 through 5 are close to universal. Beyond that, ask which building the coach learned in.
What is a nose tackle: the 0 and 1 techniques and the double team
Culp over Tingelhoff was the announcement. Through the 1970s the three-man line spread across the AFC, and with it the idea of a defender whose assignment was to stand on top of the center and refuse to move.
The classic nose tackle plays a 0 technique and two gaps. At the snap he punches the center in the chest, gets his arms extended and reads the blocker's head. If the center tries to reach him to one side, the play is going that way and the nose fights across his face. If a guard comes down to help, the nose has done his job by drawing a second blocker, and he drops his weight and holds.
That last part is the whole case for the position. An offense has five linemen. If one defender consumes two of them on every run, a linebacker somewhere is unblocked. A nose tackle who gets driven off the ball by a single center is a liability; one who cannot be moved by two men is the reason an inside linebacker finishes the year with a long list of tackles. Ted Washington, Casey Hampton and Vince Wilfork spent careers at well over 300 pounds doing this, and the men who played behind them collected the statistics.
In a four-man line the nose is a 1 technique, shaded on one shoulder of the center, and plays a single A gap. He is paired with the three-technique: whichever side the three-technique takes, the nose shades the center on the other side, so that between them the two tackles have closed an A gap and a B gap and forced the offense to block them differently.
Why the 330-pounder still has a job
The passing game has cut the nose tackle's snaps. On third-and-long there is no run to stop, a pure two-gap player offers little rush, and he jogs to the sideline. Some teams draft the position late or sign it cheaply for that reason.
Our judgment is that the box score undersells him badly. A defense that cannot hold the A gaps has to bring a safety into the box to help, and a safety in the box is a safety who is not deep. The big man in the middle is often the reason the coverage behind him can stay in two-deep shells. He affects the pass by making the run defense cost fewer players.
There is one famous variation. In 1974 Pittsburgh's Joe Greene began lining up at a sharp angle in the gap between the center and a guard, pointed across the center's body. The tilted alignment let him knife into the backfield or tie up both blockers depending on what they did, and it became a signature of the Steelers front that won four Super Bowls in six seasons.
What is a 3-technique in football: Sapp, Randle and Donald
Line a tackle up on a guard's outside shoulder and three things follow. He is aimed at the B gap. The center, busy with the nose, cannot easily slide over to help. And the offensive tackle next door has an end to deal with. The guard is alone.
That is why the three-technique is the glamour position of the interior. He is the one tackle who is expected to win by himself, on the first step, and to make plays behind the line. The coaches who built the Tampa Bay defense of the late 1990s called him the under tackle, after the "under" front that set him on the weak side away from the tight end, and they considered him the engine of the scheme. Warren Sapp was their under tackle. He was the league's Defensive Player of the Year for 1999 and went into the Pro Football Hall of Fame in 2013.
John Randle did it first and from further back. Undrafted out of a small Texas program in 1990, considered too small for the inside, he signed with Minnesota and finished his career with 137.5 sacks, the most by a defensive tackle since the statistic became official, a mark that still stood through the 2025 season. He was inducted in 2010.
Then Aaron Donald. The Rams took him 13th overall in 2014 from the University of Pittsburgh, where the knock on him was the usual one for the position: too short, too light. He was Defensive Player of the Year three times, for 2017, 2018 and 2020, and his 20.5 sacks in 2018 were, when he retired, the most by an interior lineman in a season since sacks became official in 1982. He retired after the 2023 season.
Notice what the three have in common. None was tall for a lineman. Inside, a shorter player has a natural advantage, because the man with the lower pads gets underneath his opponent and controls him. Height helps an end reach around a tackle. It does little for a player whose fight is over in the first yard.
The cost of the position is against the run. A three-technique flying upfield leaves room behind him, and offenses answer with trap plays that let him charge and then hit him from the side. A front built around a penetrating tackle accepts that trade.
Defensive tackle vs defensive end: what changes outside
Move out past the offensive tackle and the job turns from a collision into a race. The defensive end in a four-man line plays with open space on at least one side of him, and that fact shapes everything about the player.
Against the run his first duty is the edge. He must not let the ball carrier get outside him to the sideline, where there are few defenders and a lot of grass. Setting the edge means meeting the blocker with the inside arm, keeping the outside arm and leg free, and making the runner cut back toward the tackles and linebackers.
The two ends are not interchangeable.
The strong-side end lines up over or near the tight end, most often on the defense's left, and faces the offense's right tackle. He sees more double teams and more runs aimed straight at him. Teams put a bigger, stouter player there and ask him to stop the run first. Reggie White and Michael Strahan, two of the best ends who ever lived, were power players as much as speed rushers, the kind who could hold up against a tight end and a tackle together.
The weak-side end, sometimes called the open-side end because no tight end closes off his side, usually faces the left tackle. For a right-handed quarterback that is the blind side. This is the spot for the fastest rusher on the roster, and it is why left tackle became the premium position on most offensive lines.
Coaches use "base end" for a player who plays the early downs and is trusted against the run, and "rush end" for one who comes in to hunt the quarterback. A rush end's work is very nearly the same as that of a 3-4 outside linebacker, which is why the league now files both under a single word. Stances, rush moves and the rest of that craft are covered in our guide to the edge rusher, and this page stops at the point where the two overlap.
The five-technique end in a three-man line
Take one lineman off the field and the remaining three have to cover more ground with their bodies. The ends in a 3-4 play a 5 technique, a 4 or a 4i, on or about the offensive tackle, and in the classic version of the front they are two-gap players exactly like the nose.
The technique is unglamorous. Strike the tackle with both hands inside his chest. Lock the elbows out so there is separation. Keep the shoulders square to the line and find the ball. Then shed toward it. A five-technique who does this well gets his name called perhaps three times a game, and the outside linebacker next to him, kept free of the tackle's block, gets the sack.
So the ideal body is specific: around 300 pounds, with arms long enough to keep a 320-pound tackle off his chest. Richard Seymour, who won three Super Bowls with New England and entered the Hall of Fame in 2022, is the model. He rarely led anything in the statistics and was the piece the whole front leaned on.
The 4i deserves a mention of its own. Slide the end from the tackle's outside shoulder to his inside shoulder and he closes the B gap directly, which is the lane zone-running offenses most want to hit. A good many modern three-man fronts play both ends in a 4i with a nose between them for exactly that reason, and leave the C gaps to the players standing up outside.
The exception that proves how much the labels bend
J.J. Watt was listed as a 3-4 defensive end in Houston and was Defensive Player of the Year three times, for 2012, 2014 and 2015, with more than 20 sacks in two of those seasons. That is not what a two-gap five-technique does.
The explanation starts with the coordinator he arrived to in 2011. Wade Phillips, Bum's son, ran a 3-4 in which the linemen attacked single gaps, so a three-man line on the depth chart played like a four-man line on the field, and Houston went on turning Watt loose as a penetrator after Phillips had left. It is a good reminder that the number of linemen tells less than the technique they are asked to play.
What happens at the snap: get-off, hands, leverage and the shed
Every lineman at every technique goes through the same few motions in the first second and a half of a play. They happen too fast to see live, which is why line play looks like a pile.
- StanceHe sets in a three-point or four-point stance with his weight forward and his eyes on the football, not on the quarterback.
- Get-offHe moves when the ball moves. The first step is short and gains ground without raising his pads.
- HandsBoth hands strike inside the blocker's chest plate. The man whose hands land inside controls the other.
- LeverageHe keeps his pads lower than the blocker's and locks his arms out to create space between them.
- ReadThe blocker's head and feet tell him run or pass, and which way. A blocker who rises is pass protecting.
- ShedHe rips or pulls free of the block toward the ball, or converts to a pass rush move.
A general teaching sequence. The order is the same at every position on the line; what changes is whether the lineman is attacking one gap or holding two.
Watching the ball
A defensive lineman is taught to key the football and ignore the snap count, because the count is designed to fool him. If he moves early he is guilty of one of three five-yard fouls, and which one depends on whether he made contact, drew a flinch or simply was in the neutral zone when the ball was snapped. The distinctions matter because one of them gives the offense a free play; they are set out in our guide to offside, encroachment and the neutral zone infraction.
Low man wins
Coaches have repeated the phrase for a century because it is physics. The player with the lower center of mass gets under the other's shoulder pads and drives up through him. A lineman who stands up out of his stance is a lineman who is about to go backward. Good interior players are frequently described as playing "with a flat back," and a tired one can be spotted by how upright he has become in the fourth quarter.
Reading the block
Linemen do not watch the backfield. They feel and read the blocker in front of them, and each kind of block has a prescribed answer. Against a base block coming straight on, hold the gap. Against a reach block trying to get outside him, fight across the blocker's face. If the man in front blocks down inside on someone else, the lineman closes with him and looks for a puller or a trap coming. Against two blockers, get small, get low and do not get moved. Much of what looks like instinct on film is a lineman recognizing which of four or five blocks he is getting and playing the answer he has drilled since high school. The offense's side of those same blocks is described in our explainer on zone blocking.
Rushing from the inside, and why it bothers quarterbacks more
Draw the pocket from above. The quarterback is seven or so yards behind the center. The edge rushers start well outside the tackles and have to run an arc to reach him. The defensive tackles start a yard from the ball and run a straight line.
The interior route is shorter, and it is in front of the passer's eyes. It also does a second thing, which is the one quarterbacks talk about. Pressure from the outside can be escaped by stepping up. The tackles ride the ends past the quarterback, he climbs two steps into the space in front of him and throws from a clean spot. Pressure up the middle fills that space. With nowhere to step, he has to throw off his back foot, drift sideways into the ends or tuck the ball.
This is why a tackle who never touches the quarterback can still wreck a passing game. Driving a guard two yards backward flattens the front of the pocket. The quarterback cannot stride into his throw, taller linemen with their hands up are suddenly in his throwing lanes, and the ends arrive at a target who has not moved. Coaches call it pushing the pocket, and no statistic that fans see awards it to anyone. The charting services that count hurries and hits get closer, and our explainer on how pressure rate is measured describes what they record and where they disagree.
The league's shift toward quick passing sharpened the point. A ball thrown in under two and a half seconds is usually gone before an edge rusher can finish his arc. An interior rusher who wins on the first step can still get there, or at least get a hand up. Batted passes at the line are an interior lineman's play far more than an end's.
There is a blocking reason as well. An offense can help its tackle against an outside rusher by having a running back or a tight end bump him on the way out into a route. Nobody can do that for a guard. Help inside has to come from the center, and the center can only turn one way.
Interior games: tackle-tackle twists and loops on passing downs
A straight rush is four individual contests. A game, or stunt, is two linemen trading lanes to make the blockers' assignments wrong.
The simplest inside version involves the two tackles. One goes first and hard, on a slant, into the blocker next to his own. The other takes a short delay step, then loops behind his partner into the space the first man has just cleared.
- The callThe two tackles agree before the snap which is the penetrator and which is the looper.
- Penetrator goesHe drives diagonally across the center's face, aiming to hit the far guard or pin the center.
- Blockers reactThe guard in front of the penetrator follows him inside, and the center turns to help.
- Looper waitsThe second tackle takes one jab step upfield to hold his own guard in place.
- Looper comes aroundHe circles tight behind the penetrator into the lane that has opened.
- The resultEither a blocker hands off cleanly, or two men end up on the penetrator and the looper runs free.
A generic description of the stunt. Teams give it different names and vary which tackle goes first according to the protection they expect.
It works on a simple weakness. A pass blocker assigned to a man will follow that man. If two blockers both follow the penetrator, nobody is left for the looper. The answer for the offense is to pass the rushers off, each blocker taking whoever comes into his area, and that requires the center and guards to see the twist at the same instant and trust each other. Lines that have played together for years handle it. Lines with an injured starter and a replacement often do not, and defensive coordinators know exactly which lines those are.
There is a price. For a beat, the looper is going sideways and not at the quarterback, so a twist takes longer to arrive than a straight rush. Call it against a quick throw and it does nothing. Call it against a draw play or a quarterback who likes to run and it can open a lane right up the middle that nobody is assigned to. That is why interior games belong mostly to third-and-long.
The same idea run between a tackle and the end beside him has its own names and its own purpose, and it turns up in the edge rusher guide linked above. When a linebacker or a safety is added to the rush as well, the stunt becomes a pressure, the family of calls laid out in our explainer on blitz packages.
The rotation: why linemen substitute constantly and ends move inside
Offensive linemen play every snap. Defensive linemen almost never do.
The difference is in the work. An offensive lineman knows the snap count and the play. A defensive lineman reacts to both, sprints on every down, and on a long drive may do it ten or twelve times with twenty-five seconds between each. A pass rusher who is tired gets off the ball late, and a late rusher is a blocked one. So teams carry eight or nine linemen and roll them through in waves, and it is ordinary for a starting tackle to sit out a third of the defensive snaps or more.
Substitution also follows the down. On first-and-10 the run stoppers are in. On third-and-8 the defense wants four people who can rush, and the nose tackle is rarely one of them.
| Situation | Who comes off | Who comes on | What the front looks like |
|---|---|---|---|
| First and second down, base | Nobody | Nobody | Run-stopping tackles and a base end |
| Third-and-long | Nose tackle | An extra pass rusher | Four rushers, lighter and quicker |
| Third-and-long, sub rush | Nose tackle and a base end | Two extra edge players | Ends moved inside over the guards |
| Goal line | A defensive back | An extra tackle | Five or six linemen, gaps packed |
| Hurry-up offense | Whoever is trapped | Nobody | The group that was on the field stays |
The third row is the interesting one. A defensive end who weighs 270 pounds is too light to play tackle on first down. On third-and-long nobody is going to run at him, and against a 320-pound guard his quickness is a mismatch. The New York Giants teams that won Super Bowls XLII and XLVI made a habit of putting four defensive ends on the field at once on passing downs, a group that came to be known as the NASCAR package for its speed. Half the league copied the idea, and it is one reason the passing-down defense described in our explainer on nickel and dime packages has become most teams' real starting lineup.
The hurry-up row is the offense's counter. The rules give the defense a chance to match personnel whenever the offense substitutes. If the offense changes nobody and snaps quickly, the defense is stuck with the eleven it has, and a no-huddle drive is often aimed squarely at keeping three tired linemen and a nose tackle on the field against the pass.
Size by position, and the names that came before
No rule sets a weight for any position. What follows is how scouts tend to describe each spot, and the exceptions are numerous.
| Position | Typical build | What the build is for |
|---|---|---|
| Nose tackle | About 320 to 350 pounds | Holding ground against two blockers |
| Three-technique tackle | About 285 to 310 pounds | A fast first step in a short space |
| Five-technique end (3-4) | About 290 to 310 pounds, long arms | Keeping an offensive tackle at arm's length |
| Strong-side end (4-3) | About 265 to 285 pounds | Setting the edge against a tackle and tight end |
| Weak-side end (4-3) | About 250 to 270 pounds | Speed and bend around the corner |
Older broadcasts and older books use names that have mostly dropped out.
The middle guard was the man over the center in the five-man lines of the 1940s and early 1950s. The name is a leftover from two-way football, when the men in the middle of the defensive line were the same men who played guard on offense. When Chicago's Bill George began standing up and backing off the ball in the mid-1950s, the middle guard turned into the middle linebacker, a story told in our guide to the Mike, the Will and the Sam. The nose tackle of the 1970s was, in effect, the middle guard brought back.
The under tackle is the three-technique in an under front, as described above. Left end and right end once named offensive players too, in the days when the men at the ends of the offensive line were simply the ends. That is where the tight end and the split end got their names.
And the great fronts had names of their own.
| Nickname | Team and era | The four |
|---|---|---|
| Fearsome Foursome | Los Angeles Rams, 1960s | Deacon Jones, Merlin Olsen, Rosey Grier, Lamar Lundy |
| Purple People Eaters | Minnesota Vikings, late 1960s and 1970s | Alan Page, Carl Eller, Jim Marshall, Gary Larsen |
| Steel Curtain | Pittsburgh Steelers, 1970s | Joe Greene, L.C. Greenwood, Ernie Holmes, Dwight White |
| New York Sack Exchange | New York Jets, early 1980s | Mark Gastineau, Joe Klecko, Marty Lyons, Abdul Salaam |
Each of those was a four-man line with two tackles and two ends, and each defined its team for a decade. Alan Page, a tackle, was voted the league's Most Valuable Player for 1971, the first defensive player to win the Associated Press award. Nicknames for a front four have become rare, and the reason is on this page. The four who start are seldom the four who finish a drive, the ends may be linebackers by title, and on third down the tackles may be ends. The positions have not disappeared. They have become assignments that players rotate through, and the place they fit among the other twenty-one is laid out across our American football coverage.