boy everyone gets caught up in the personnel to define a defense and really that is not a big deal. Whether a 4-2-5 or a 4-3 you align against the offense's set. If you have a 4-2 personnel in, and the offense lines up in 21 or 12 personnel, that 5th db, typically a nickel back who plays inside and is a bit more physical than a normal db, will drop down into the box in the same spot a 4-3 linebacker would be, and the defense is played identically whether a 4-3 or 4-2. You will have the same coverages. The same assignments etc. The difference being you have a smaller body in the box, than a 4-3. But its the same defense.
Plus to a 4-2 are simply teams today seem to always be in 11 10 or 01 personnel. There is always 3 WR. Having a lb cover that slot wr can be tough for him. The down side is if you run out of a 3wr set, in 11 personnel specifically, a 4-2 DB trying to take the place of a LB gets eaten up. Bigtime. so this is the issue. Against a run team, like Pitt, you would see more 4-3 since we wanted bigger bodies out there.
IMO, teams that exploit the 4-2 personnel choice the most are teams like clemson, duke, UGA, and FSU. These teams run a TON of 11 and 20 personnel. They are 3 wr sets, that have a power run game off it. It makes it hard to predict what they are going to do. They power run in 11 or 20 personnel, and you have your 4-2 people in you get eaten up. They run alot of QB power plays off it, counters and traps and we don't handle it well.
One reason why we don't handle it well is our front 6 or 7 has very little presnap movement. Our DL never stems, We never or rarely line up in one look and shift changing the blocking look for the OL to mess with them. We just stand there.
The best defenses exploit weaknesses in the OL blocking schemes. Whether run blocking or pass blocking. Good DCs see OL tendencies and weaknesses and create specific blitz and shift packages to exploit that. You attack the line scheme. Not just rush 5 blindly. Or 4. Or simply blitz a dumb obvious AGap blitz. You create confusion by presnap angle changes, moves from i alignment to head up or outer. You see a guard who struggles with a odd front and a end t twist with a blitzing OLB while the end backs into zone and you attack him. You exploit him until the offense rolls the TE or RB to help. And when the offense does that you mimic that look, don't zone blitz and on the opposite side of the line (now that the RB is helping on the other side) you overload blitz or fire cats all day.
You need to be multiple in your pressure packages.
So I will stop here. And simply say. I have yet to see anything that resembles this since Wommack to be honest. We gave him 2 years, but he did do this....not sure he would have been a good DC here. I am just saying scheme wise he did this and no one else since has. Groh typically had his packages but were very man up and fit oriented, taking 2. The Guy Now, eh doesn't really do much more than very basics. Cover 2. Man free on the back, with head up and an occasional S blitz that is usually late, OLB or MLB A gap fire...thats about it. In a 3-4 he may rush one of the OLB too.
I have yet to see a DC purposely create packages to attack an offense blocking scheme purposely. We seem to just call our plays, which now are almost telegraphic obvious and hope. Again, we have maybe one of the most basic defensive schemes i have seen. More shockingly, is we have one that is so basic with a bunch of seniors and juniors. Its one thing for them to be freshman and soph. You know what, I just need to stop for now. Ugh. Hurts me in the head.
Thanks for the chart! 
