It's a long read, but it's very worth it. It goes into some great detail and gives great examples. Enjoy! http://subscribers.footballguys.com/2009/09bramel_idpguide.php
Anything to not get dragged in to the LT rape thread, there's just too much potential for things to go wrong there.
That is an excellent article, but I have to take issue with the idea that the 46 is a relic. While it isn't a valid base defensive set anymore, the philosophy for that defense was used with fantastic success by the 2009/10 Super Bowl champion Saints and the #1 NFL defense of the Jets. I know that this article was written a few years ago, but it's funny to see him reference Gregg Williams and Rex Ryan, since they were running the D's of the 2 teams I just named.
I think you're taking the word "relic" with too negative a connotation. The Wildcat is a relic, it's the old single wing, yet it still works. Just because something is old (though the single wing is a LOT older than the 46 defense) doesn't necessarily means it's bad.
The 46 as the formation may have gone the Dodo's way, but the spirit still lives - and you can see it still breathing in Jets D.
Very good article. If I'm reading it right, the crux of the 46 defense is that it needs a strong secondary to run it properly. The over-blitzing/pressuring, if you want to call it that, should in theory force a lot of quick throws from the QB, running for his life. If you can lock down the receivers, it allows the linemen/LBs to get the pressure needed to force mistakes. Now that we have improved the secondary, again, in theory it should help the line get upfield better. The OL can only hold off 6 or 7 rushers so long, so we should see more coverage sacks, as the general state of the pass rush improves. Then again, I may be reading this completely wrong, and that's why I'm sitting in my office, tapping this out on a computer and not coaching instead.