There has been a lot of confusion on the part of fans, including myself, about some of the basic football terminology, formations, and tactics of defensive fronts in the NFL. I hope this primer on the subject will help clarify the subject somewhat.

First, let’s start off with some basic terminology.

Technique: A numerical identification system is used to describe where defensive linemen and possibly linebackers will line up against an offensive front (offensive linemen and tight ends).


These numbers are referred to as techniques – a misnomer because the term does not really apply to an actual technique, but rather the position of the defensive player at the line of scrimmage.

Coaches, scouts, players, and draftniks will often refer to defensive tackles as being a 1-technique or a 3-technique player. In these circumstances, they are usually describing a TYPE of player that is best suited to lining up in a 1-technique or 3-technique position. A defensive tackle lining up at the 0- or 1-technique is going to see a lot of double teams from the center and guard. Because of this, one-technique tackles are usually big, strong, and stout, but less athletic. The other tackle (or 3-technique tackle) is usually the quicker, more active penetrator. A 1-technique tackle in a 4-3 defense is sometimes called a nose tackle even though most fans think of a traditional nose tackle being in a 3-4 defense. The 3-technique tackle is sometimes referred to as an under tackle.

The two outer 0-technique positions are often referred to as the shade technique because the defensive tackle is not lined up directly over the center, but puts his facemask near the center’s shoulder and angles his body diagonally so that his rear end is more toward the guard. The front will determine which side the shade is toward. The “nose tackle” usually will rush away from the double-team on a passing down, and towards the double-team on a running down. Against the run, the nose tackle wants to draw the double-team to allow the linebackers to plug the holes and make the play. On a pass, he wants to shoot the gap and get upfield penetration.

One-Gap versus Two-Gap Defensive Lineman: Depending on the play called, the defensive scheme, and the overall philosophy of the defensive coordinator, a defensive lineman could be responsible for either one or two gaps. In a one-gap scheme, the defensive lineman attacks a particular hole (i.e., gap) in the offensive front and is responsible for any action directed at that gap. Against the run, the defensive lineman is expected to tackle the back who goes through that hole or force the back to move laterally into the arms of another defender. One-gap style defenders are usually quicker, faster and more athletic, but not as big and stout. In a two-gap scheme, the defensive lineman is responsible for two holes (i.e., gaps) in the offensive front. His job is really not to penetrate like a one-gap defender, but play more disciplined football by holding his ground, reading where the play is heading, and clogging the more important gap. Two-gap style defenders are usually bigger, stronger, and more stout at the point-of-attack, but less athletic.

The key point here is that a defensive lineman who is particularly well suited to one scheme usually is not well suited to the other. Thus, it is usually not easy or advisable for a defense to switch from a base one-gap scheme (usually a 4-3 defense) to a base two-gap scheme (usually a 3-4 defense) unless that team intends to dramatically change its personnel. For example, Michael Strahan, Osi Umenyiora, Justin Tuck, and Mathias Kiwanuka would not make good two-gap defenders. Not only would it be a waste of their talent (because you are asking them to read-and-react rather than attack), but they are not physically well suited for that style of defense. 3-4 defensive ends are usually built more like defensive tackles along the lines of Leonard Marshall, Eric Dorsey, John Washington, Curtis McGriff, and Dee Hardison of the Giants’ defenses of the 1980’s and early 1990’s. Or in more contemporary terms, Ty Warren and Richard Seymour of the Patriots are other examples.

Choosing a Base Defense: 4-3 or 3-4: Every NFL team uses either a 4-3 or 3-4 base defense. The 4-3 defense employs four defensive linemen and three linebackers while the 3-4 uses three defensive linemen and four linebackers. The 4-3 defense is mostly a one-gap style of defense while a 3-4 defense is exclusively a two-gap style of defense.

The 4-3 Defense: The 4-3 was actually devised in 1950 by Hall of Fame New York Giants’ Head Coach Steve Owen as a situational package that was part of his overall “umbrella” defense. Owen’s defensive captain at the time was defensive back Tom Landry. Landry went on to become the full-time defensive coordinator of the Giants from 1956-59 under Head Coach Jim Lee Howell. The Giants’ 4-3 defenses of the 1950’s and early 1960’s helped the Giants make it to six NFL Championship Games, winning one in 1956. Landry’s Dallas 4-3 “Flex” defense later became famous in the 1970’s and 1980’s. (But we won’t discuss the “Flex” here).

The 4-3 defense puts a premium on defensive ends who can rush the passer and who are ideally solid run defenders. The ends are attackers – one-gap players – who disrupt the opposing offense. The defensive tackles should be good run defenders, although one should be a quicker, more disruptive player while the other is adept at taking on double-team blocks. The strongside linebacker is generally the bigger and more physical outside linebacker while the weakside linebacker is usually faster and more athletic. (Note: The strongside of the defense is the side of the defense where the tight end lines up). The middle linebacker should be smart enough to direct the defense, and athletically gifted enough to run from sideline-to-sideline and be a physical presence against the running game. Ideally, in today’s pass-happy game, he is good in coverage too.

When most fans think of the 4-3 defense, they think of the straight 4-3 or the 4-3 Stack:


Why do most fans think of the 4-3 in terms of the 4-3 Stack? Because the defensive linemen and linebackers are roughly equally interspersed with each other and on parallel lines. It’s symmetrical and easy to understand. All three linebackers are off the line of scrimmage. Both defensive ends are lined up wide at the end of the line with the outside linebackers lined up inside the ends. The middle linebacker is usually approximately in line with the center.

But the truth of the matter is that all pro teams, including the Giants, use a wide variety of 4-3 fronts. Two of the most common are the 4-3 Over and the 4-3 Under. The objective of these defenses is to either shift the focal point (in terms of more bodies) of the defense to the offense’s weakside (4-3 Over) or strongside (4-3 Under) while potentially creating some favorable match-up opportunities for specific defensive linemen on the opposite side.


In the over shift, the weakside end (Osi Umenyiora) and the weakside tackle (Damane Duckett/Jonas Seawright) shift slightly toward the strongside of the offensive formation. (In the 4-3 Over, the weakside tackle becomes the nose tackle). If the tight end goes out on a pass pattern, it creates some favorable one-on-one match-ups on the strongside for the defensive line. However, since the middle linebacker and the weakside linebacker shift more to the weakside, notice that four of the front seven defenders are now lined up to the right of the center or the weakside. In terms of specifics, the strongside or left defensive end (Michael Strahan) will line up over and usually outside the tight end (9-technique). The left defensive tackle (William Joseph) will usually line up off the right shoulder of the right guard (3-technique). The right defensive tackle (Duckett or Seawright) will line up between the center and the left guard in the nose tackle position (0- or 1-technique). The right defensive end (Umenyiora) will usually line up over the left tackle (5-technique). The weakside linebacker (Carlos Emmons) is now outside the right end and will cheat up to towards or be at the line of scrimmage. The middle linebacker (Antonio Pierce) is usually shifted towards the weakside of the formation. In the over shift, the tight end can be jammed by Strahan.

In the under shift, three of the defensive linemen are shifted toward the weakside of the defense and there are favorable one-on-one match-ups on the weakside for the defensive line. However, since the middle linebacker and the strongside linebacker shift more to the strongside, notice that four of the front seven defenders are now lined up to the left of the center or the strongside. In terms of specifics, instead of playing outside the tight end in the 9-technique, Strahan will line up over the right shoulder of the right tackle in the 6-technique position. Umenyiora will line up over the left shoulder of the left tackle, also in the 6-technqiue position. The nose tackle (0- or 1-technque) will now be on the left side between the center and right guard. Joseph, as the 3-technique tackle, is now on the right side lined up off the left shoulder of the left guard. In this defense, LaVar Arrington, as the strongside linebacker, will line up at the line of scrimmage in the 9-technqiue position off the shoulder of the tight end. Pierce and Emmons are shifted towards the strongside of the formation. In the under shift, Arrington can jam the tight end.

Not to confuse you too much more, but keep in mind that opposing offenses can shift their tight end to the opposite end of the line of scrimmage, thereby changing the strongside to the left side of the offensive formation. The defense will react accordingly. Also, teams can run two tight end formations. In addition, the Giants are not wed to keeping Arrington on the strongside and Emmons on the weakside. Both players have experience at both positions and might flip. But since Emmons can play over a tight end, even if the tight end goes in motion to the opposite side, the Giants don’t necessarily have to adjust. William Joseph also has the ability to play some nose tackle and there are other tackles on the roster who can play the 3-technique position such as Fred Robbins (who also has played some nose).

Nickel and Dime Packages: Once you get an opposing offense in a more obvious passing situation, any defense will switch to their nickel (five defensive backs) or dime (six defensive backs) packages. In fact, because more teams are using three wide-receiver packages more often, including in their base offense, the Giants may be forced to play a nickel defense for most of a game. When a team switches to a nickel, almost always it means a linebacker will come off the field in favor of another defensive back. When a team goes to the dime, it could be another linebacker or even a defensive lineman. Most teams will pull their strongside linebacker first because this guy is usually the least athletic back-seven player on the field. But that most likely will not be the case with the Giants now with Arrington on the roster since Arrington is a very good potential pass rusher. It is more likely that Emmons will come off of the field. The defensive backs in the nickel will probably be FS Will Demps, SS Gibril Wilson, CB Sam Madison, CB R.W. McQuarters, and CB Corey Webster. But S James Butler and CB Curtis Deloatch are other possibilities – especially when the Giants switch to the dime.

The overall defensive philosophy for the Giants, in terms of pass rush, will be to rush four or five defenders from any gap and not have the same down four rushing from the same gaps. This will put pressure on the opposing blocking schemes to adjust and not make mental mistakes. If those mental breakdowns occur, there will be immediate pressure on the quarterback, resulting in sacks or turnovers.

Take a look at the potential 4-2-5 nickel package below. The nice thing about this package is that all seven players shown in the box are good pass rushers or blitzers. Furthermore, three of the defensive linemen (Strahan, Umenyiora, and Tuck) are athletic enough to drop into coverage in a zone blitz scheme. The Giants have even dropped William Joseph in the past.


Zone Blitz: What do I mean by zone blitz? A zone blitz is a defensive concept that tries to confuse opposing offenses by blitzing linebackers and/or defensive backs while at the same time dropping defensive linemen into coverage, filling the vacated zone. When a zone blitz works for a defense is when it confuses the opposing quarterback – slowing his decision-making process or causing him to make a poor decision. It also can confuse the offensive front’s blocking schemes to the point where some offensive linemen may be blocking no one while others are facing more defenders than they can successfully block. When a zone blitz does not work is when the opposing offense successfully picks up the rushers and the quarterback makes a timely, correct decision. In those cases, a defense may get caught in a mismatch where you have a defensive lineman trying to cover a niftier receiver such as a halfback in his zone. In other words, a zone blitz can work great or make a defense look silly. It depends on the ability of the opposing offense to execute under duress. Tim Lewis does like to zone blitz.

The 3-4/3-3-5 Defense: As mentioned above, the 3-4 defense employs three defensive linemen and four linebackers. It is a two-gap system. The role of the defensive linemen in this system is to not attack, but to hold the point-of-attack, read-and-react, and keep opposing offensive linemen off the linebackers as much as possible. 3-4 defensive ends usually are not playmakers, but gap fillers. The 3-4 places a premium on linebackers, who tend to be bigger and more physical than 4-3 linebackers. The 3-4 defense is generally better at stopping the run rather than rushing the passer unless you have a star outside linebacker along the lines of a Lawrence Taylor, Andre Tippett, or Joey Porter. It is also somewhat easier to confuse an opposing offense with a 3-4 scheme in that an offense may be less able to accurately predict which linebackers are coming and which are dropping. It also makes it easier to cover underneath in the event of a blitz because there is one more linebacker on the field.

The Giants do not have the defensive personnel to run a base 3-4 defense. But their defensive coordinator, Tim Lewis, has a 3-4 background and will use 3-4 looks at certain times in a contest – usually on passing downs. These defenses will likely be more like 3-3-5 packages with one safety moved up, giving a 3-4 look. With all of the personnel changes on defense this offseason, it is difficult to predict what one of Lewis’ situational 3-4 packages might look like, but here is one guess:


This would not be the type of formation you would want to play on a running down because Strahan and Justin Tuck are not two-gap defensive ends. Plus, with the Giants likely being in the nickel, Gibril Wilson or another safety would likely line up closer to the line of scrimmage in a linebacker-like position. But this formation would be conducive to having Umenyiora and Arrington come off the edge on a blitz, or confuse the quarterback by dropping into coverage, or confuse the quarterback even more by enabling the Giants to zone blitz more effectively.

In this package, the Giants could begin with a pre-snap look of having three down linemen, but you could have Umenyiora or Arrington switch to the down position and/or have some of the down linemen drop before or after the ball is snapped. When you factor in a potential blitz from Pierce or defensive backs, this could become very confusing to an opposing offense. In such a scheme, as with the zone blitz mentioned above, you would like play short zone coverage underneath rather than man-to-man as you usually don’t want defensive linemen – albeit extremely athletic ones – to have to stick to a receiver in coverage in such a situation. The keys to these more exotic defenses are to create confusion and generate immediate pass pressure.

Another important point to emphasize is the physical make-up of the Giants’ front seven is somewhat unique. The Giants now have five very athletic defensive ends who can actually drop into space – Strahan, Umenyiora, Tuck, Mathias Kiwanuka, and Eric Moore. They also have relatively large outside linebackers who are of similar size as their defensive ends – Arrington, Emmons, Reggie Torbor, Brandon Short, and Gerris Wilkinson. Torbor and Wilkinson have collegiate experience at defensive end while Arrington also has played from the down position at the pro level in certain packages. My point? Tim Lewis and the Giants could potentially do some pretty wacky things with the existing personnel on the roster – things that could confuse the heck out of an opposing offense.

So there you have some defensive front-seven basics. What will be interesting to watch this year is how Tim Lewis uses all his new defensive weapons both in run and pass defense.