I'm in dire need of an Education

[Smeefers]

My fellow Rats; I'm ashamed to say that there's some things that I don't understand. I humbly come before you in order to get clarification and instruction.

I don't know the differences between the 3-4 defenses. There's a 2 gap and a 3 gap right? What in the world does this mean? I don't get it. How are they different? Then people start talking about a 5-tech or something along those lines and I'm lost again. I think it means where a person lines up, but I really have no idea where a #5 would be, let alone any other number.

[Lurker64]

Okay. Cliffs notes version.

Gaps:
No human being is able to assume 3-gap responsibilities, the distinction is between 1-gap players and 2-gap players. A "gap" is what the offensive side of the football would call a potential "hole" and there are gaps between the left tackle and left guard, the left guard and the center, etc. A basic principle of defense in the modern NFL is "gap control". Specifically "a running back will not be able to gain many yards on us if all of the gaps (his potential holes) are filled with our players. A player with 2-gap responsibilities is responsible for maintaining control of two gaps, for example the nose guard in a 3-4 defense may be responsible for taking the gaps on either side of the center. A player with one gap responsibilities, simply has to charge upfield through his gap.

Techniques:
This is just in reference to how defensive players line up in reference to offensive players.
0-technique is head-up on the center
1/2/3-techniques are inside shoulder/head up/outside shoulder on the guard
4/5/6-techniques are inside shoulder/head up/outside shoulder on the tackle
7/8/9-techniques are inside shoulder/head up/outside shoulder on the tight end.

The distinction between a 6-tech and a 7-tech when there is no tight end on that side is really the difference between "do you line up to run at the OT, or around him".

If you recall the defense we had under Jim Bates (which was also Jimmy Johnson's superbowl winning defense), the defensive ends would generally line up in a 7-technique and a 9-technique, while the tackles would generally play a 3-technique.

If you look at the base 3-4 that we run in theory (but seldom in practice) our defensive ends line up in the 5-technique, while the nose tackle is generally in a 0-technique or a 1-technique.