FanPost

In Fangio's 4-3 Under, will Shelby/Kerr work as NT's?

While many of us Bronco fans are excited about this off-season (and with good reason!), there remain one or two major needs on defense: an ILB who can cover, and (depending on who you ask), a SS. However, might there be a 3rd major need to address in this draft?

With Kerr being retained, as well as Shelby Harris being tendered, many fans assume that the Bronco's are now set at NT, having secured two of Fangio's "prototypical nose tackles who can eat up double teams."

However, Fangio does NOT run a typical 3-4 defense, and he does NOT utilize a "two-gap" scheme.

Fangio runs a 4-3 Under, meaning the NT lines up as a 1-tech, and has one-gap responsibility (as opposed to a 3-4 where the NT lines up as a 0-tech and has two-gap responsibility).

"In Fangio’s scheme, the NT ... lines up off the center’s shoulder on the strong-side (same side as TE) and is only responsible for the gap in front of him. This requires a different type of NT as opposed to the classic space-eater used in standard 3-4 schemes. The NT in Fangio’s scheme needs to have the quickness to beat interior lineman off the snap and the strength to hold his ground against double-teams in the run game." - Mike Flannery

In a 4-3 Under, the NT needs to penetrate, not simply absorb two blocks and stop the run:

The beauty of the 4-3 under is that you can play it with essentially the same type of athletes as the traditional 3-4, to an extent. What we haven't touched on is the fact that while the true 3-4 uses 2-gap defensive linemen (as mentioned earlier in the post, making plays on either side of their man), the 4-3 under is a 1-gap principle. This means that each player is responsible for penetrating the gap in front of him, not standing and holding the point. The inside linebackers will handle anything that comes through the open gaps.

[You] can essentially play the under front with 3-4 personnel, but they must be guys who are capable of penetrating. The idea is that if they are a threat to penetrate the gap, the offense double teams them, taking a blocker out of the equation ... a blocker who could have otherwise released and tied up the linebackers. To a degree, a strong player who isn't the quickest penetrator can still play in a 1-gap system as long as he uses his strength to occupy two blockers. If he can't do that the offense will simply send the adjacent lineman off to clean up the linebacker, and now the running back is seven yards down the field, untouched.

The nose tackle must be a large man who can withstand constant double-teams from the center and guard. Many 0-tech NTs in the 3-4 can also handle playing the 1-tech in an under front, but not all of them." -
Tre9er

For you nerds, here are two sources that dive into Fangio's defensive system (which I quoted above); the first is a great intro read for persons just getting familiar with some of these concepts, the 2nd article drives the points home:

  1. Author: Mike Flannery https://beargoggleson.com/2015/01/21/vic-fangios-defensive-scheme/
  2. Author: Tre9er https://www.ninersnation.com/2013/5/2/4294242/football-university-49ers-defensive-fronts-vic-fangio-3-4-nickel-4-3-under

I'll be honest, until I dove into Fangio's scheme, I assumed that Kerr & Shelby would be a good fit, but now I'm not so sure. Hit me up with thoughts in the comments and/or vote in the poll!

This is a Fan-Created Comment on MileHighReport.com. The opinion here is not necessarily shared by the editorial staff of MHR.