This is the sixth article in a series of articles where I will talk about the basics of Football 101.

• The precursor to the first article: Is This Really Air Garrett
• The first article in the series: What Are All These Numbers And Letters
• The second article in the series: The Receiver Route Tree
• The third article in the series: Air Garrett Part II
• The forth article in the series: Defensive Secondary
• The fifth article in the series: TightEnds

In the last article I talked about the Tight End position, and in this article I will deal with the basics of one of the positions on defense, the Defensive Line. I will talk about the basic philosophy and some of the defensive sets that counter the offensive blocking schemes and cover only a few of the main ones in this article and leave more for the next article which will be to continue with the Defensive Line blocking schemes.

First there are two basic ways that the defensive line can handle their gap assignments. (To understand gaps, see my first article What Are All These Numbers And Letters.)

1. The Two gap technique - This is where each of the defensive linemen have two gaps that they are responsible for. For example in the 3-4 defense, the NT will line up in the "Zero" technique and can be responsible for both "A" gaps, the DE's can be responsible for the "B" gap and "C" gap on his side of the center. The two-gap can be used on both the 3-4 front as well as the 4-3 front. With this technique, the Defensive linemen are taught to get lower than the guy in front of them, and then hold their ground, stand him up while waiting to see which hole the ball carrier comes thru and then shed the block and tackle the ball carrier. The advantage of this technique is that you can cover 6 gaps with 3 linemen which leaves more guys to play to the ball. The disadvantage is that if you are responsible for two gaps, it is harder to "shoot" one of your two gaps, (the ball carrier might go thru the other one), and play in the backfield. Traditionally in this type of system, the NT is a true space eater and weights between 320 and 350 lbs, because quickness is not a premium.

2. The One gap technique - This is where in a 3-4 front, the NT will play the "1" technique, (Line up shading on either side of the center), and the DE's can play either the "3" technique or the "5" technique, while Linebackers are responsible for the other gaps. The advantage of this is the Defensive Linemen are allowed to "shoot" the gap and play in the backfield. The disadvantage of this technique is that the Offensive Linemen are often free to get on your linebackers in the second level and that can result in more long runs by the running backs. In this type of system, the NT can be a little smaller, because there is less need to stand the guy up in front of you all the time since you can use your quickness to penetrate your only gap responsibility. However, the Offensive Linemen may choose to double team that gap and wear down the NT. This can be to the defense's advantage in that one of the things hoped for is to have your NT be good enough to draw a double team because that allows more one on one pass rushers. (This one gap technique was invented by Bum Phillips and is still used by his son Wade Phillips.)

Many teams use a combination of both of these techniques. For more information on the "Bum Phillips" One gap 3-4 technique, goto This Link.

Next, there is another basic technique of just how the Defensive Line handles the approximately 50 different blocking techniques that are available to the Offensive Line.

Also, notice that on good defenses, the down linemen will shift to a different position, (NT may move from the "1" technique on the strong side to the "1" technique on the weak side, etc), just before the snap to confuse or defeat the offensive line blocking assignments.

These techniques fall into 4 main categories:

1. One-Man blocks
2. Two-Man blocks
3. Pull blocks
4. Pass Sets

Each of these four categories will be in multiple blocking schemes. For example, in the Two-Man blocking scheme, you can find all of the following Sub Category blocks:

1. Double Team block
2. Combo block
3. Fold block
4. Tag block
5. Gut block
6. Scoop block
7. Zone block
8. Influence and Kick-Out block
9. Down and Kick-Out block
10. Down and Log block
11. Down and Load block

See: Coaching the 46 Defense by Rex Ryan and Jeff Walker

Once a Defensive Coordinator who may just be starting out realizes just how many different blocking techniques there are, he has to decide on one of two different teaching philosophies to handle or counter these techniques.

First is what is called the "Comprehensive" philosophy, and the other is called the "Generic" philosophy.

In the Comprehensive philosophy, the Defensive Coordinator must teach the proper "counter" to each of these techniques which requires an enormous amount of "teaching" and "practice" time. Even though this comprehensive philosophy was common in the past, many of todays DC's feel it is too time consuming to be practicle. Also, another disadvantage of this philosophy is what is called the "read conflict." For instance if the Offensive Lineman takes an inside angle against the Defensive Lineman it can be for one of two reasons. First, it could be to get to the Linebacker and second it could be to get an inside position so he can then "seal" that Defensive Lineman to the outside since the RB is going inside.

In the other Philosophy, it is taught that there can be "one sound" response that can handle many different offensive blocking techniques. This philosophy will make it to where the defensive linemen can react quicker because they dont have to analyze as much as they otherwise would, and they have less of a chance to "guess" wrong if there is a "read conflict."

Some Defensive Coordinators teach that the role of the Defensive Linemen have two basic rules.

1. Don't allow the "reach block"
2. Don't allow the "jump-through"

For an Outside-Shaded Defensive Lineman, he must maintaining Outside Leverage and defeat the reach block, (also called the hook block.)

Next, he must not allow a successful jump-through block. This means the offensive lineman is trying to jump-through the hole and reach the next level. Often also called the "scoop" block because he will try to scoop inside.

In the next article I will discuss several more of the 11 Sub Category basic blocking techniques.