You hear it all the time, especially around draft time. "So and so would be a good 5 technique" or "this team is looking for a stud defensive tackle to play the 3 technique. Most people just dismiss this as technical jargon that they don't understand. Here is an explanation of what they mean by these different techniques.
The defensive line technique is nothing but a numbering system. All it is designed to do detail out the alignment of the defensive lineman. It does not describe how to play a 2 technique for example, which is way beyond the scope of this blog entry.
Below is an illustration of the defensive line technique. The numbers represent the technique, and the letters represent the gaps, which you also hear quite often from TV commentators. For instance, "He blitz right up the A gap". So now you know what gaps they are talking about as well if you didn't already.
What the numbering system really does is tell you if a player on the defensive front is lining up over the left shoulder, directly in front of the offensive lineman, or his right shoulder. So a defensive tackle playing the 1 technique could line up on either the center's left or right shoulder, as shown above. If the defensive tackle is in a two technique, rushing the right guard, then he is lined up over the guard’s left shoulder, covering the "A" gap. You should be picking up on the pattern by now.
Its that simple really. Keep in mind this is not the Gospel. Every team likes to throw in their own variants, but 95% of the time, you'll find this information to be true. The important thing is that you know how to read and understand the different techniques.