Starting Linebacker

I started my pursuit of knowledge for coaching linebackers in football recently. I got a book from my Dad for Christmas. Coaching Linebackers: By the Experts from Coaches Choice. It features a bible compiled from various coaches throughout the NCAA including Wisconson's Barry Alvarez and Jerry Sandusky from Penn State (aka "LineBacker U").

I realized right away that I lack a lot of the very basics of football knowledge. The book started talking about "a 9 and a 5 technique, and the nose guard is in the 1 gap on the strongside". What?? I figured out the 1 gap on the strongside, but I always thought that defenses called it the Strongside A Gap. And 5 technique?! I am lost.

So I hopped on Google. I found out that the gap numbers are actually used for the alignment of defensive players. If I have a nose tackle in the 1 gap on the strongside, he is lined up on the center, but shaded to the strongside (side of the tightend) gap between the center and guard. The gaps are indeed lettered A, B, and C, and are used to assign responsibility, and not alignment. Here's a MS Paint Original Diagram -

The only thing I can figure for a "9 technique" is that the outer-most alignment must default to a nine technique. On the weakside above, where the 5 should be would actually be a 9. On the strong side, the 7 would become a 9. I am not to sure on this, but it seems to add up.

Once you know where your D-line is going to line up, it seems easy to coach the linebackers on what needs to be filled. If we have 4 D-Linemen at the 9-5-1 strong and 3 weak, we will have the strong side B and weak side A and contain(9 or C??) gaps uncovered. Another wondrous piece for you:

I am not sure if this is a legitimate formation or not, but you can see how the linebackers need to adjust according to their reads at the snap. A strongside run would bring this Middle LB into the strong B gap. What reads these linebackers have and how to train them to react to these reads I don't know yet. That's for another day.

Brandon

Edit 1/8/2007:

So this might be the actual numbering that the book was using. Odds on the left side, evens on the right, with 9 technique representing a "contain" outer most rush. Not quite sure though.