3-4 Run Defense: Part III

This is Part III in our series on run defense in the 3-4 scheme; today we look at defending the run against 20 personnel.

You don't often see much 20 personnel sets in college football today. If a team is running true 20 personnel, 90% of the time it is on third down, and you are going to see a pass. If they go to shotgun in 20 personnel, they're going max protect so it is a pass. We're discussing defending the running game right now, though, so we're going to look at the rushing possibilities from 20 personnel.

3-4 Run Defense vs Split Backs (click to embiggen)

The first thing you notice is the reduction of gaps; with two backs, no tight ends, we're looking at only five offensive linemen, so just six gaps to defend. Each back represents an additional gap, but since one is the ballcarrier, we're only looking at needing to defend 7 potential gaps aganst this formation. We can therefore justify taking the SS out of the box, and playing him on the slot receiver to defend against the pass, because we don't need the 8-man front to cover all the gaps. We have moved the SOLB down to a 5 (so our front is now 5,3,1,3,5), our Mike ILB to a 20 tech, and our Will ILB to a 20 tech, too. We are aligned Over to the strongside, because we cant to be able to brng pressure on the QB while also being ready to defend both the pass and run game. 

From 20 personnel, when they do decide to run, you will mostly see Lead to the strongside, Power to the strongside, Dive off the weak A-gap, and Sweep strongside. That is pretty much it; the defense knows when they see this formation, they need to expect pass, especially on 2nd and 3rd with long yardage to go.

The second formation to look at is 20 personnel with the QB aligned in the shotgun.

 3-4 Defense Vs Shotgun Split Backs (click to embiggen)

If you see 20 personnel go to shotgun split backs, and it isn't a passing down, you're looking at an option team. Zone Read, Zone Read Option, Midline, and Dive are the main plays to watch for from this formation. The Mike ILB and NG are responsible for stopping the Dive, and on Zone Read Option, the playside OLB gets between the QB and the pitch man, feathering out the read long enough for Will to stuff the run. The won't run Zone Read Option strongside because they are outnumbered and out-gapped to that side. The NG and DEs need to be drilled to take the most dangerous ballcarrier on that play; Mike or Will will be charging the gaps and stuff the other runner. We haven't had a team go shotgun 20 personnel in the Big 12 since A&M ran a zone read option attack under Franchione. There is a possibility we might see some option from this formation by Nebraska this year, but I doubt it.

Of the teams we will face in 2010, I think only Texas Tech runs 20 personnel, and 99.9% of the itme when they show that, it is a Lead play to the left or right, and they don't pull linemen, so the LBs can actually read the backs. Against a 3-4 defense, I don't think they'll even try to run that, because it asks too much of their tackles to handle an OLB.