In modern football, there are 2 popular base defensive sets. Most teams run either a 3-4 Base or a 4-3 Base.
The quick explanation of these defenses is that the first number (“3” in a 3-4) is your number of Down Linemen (literally people who line up with their hand on the ground in a 3 or 4 point stance on the line of scrimmage) and the second number (“4” in a 3-4) is your number of linebackers (people who line up in a 2 point stance, behind the down linemen).
This diary will discuss the 4-3 Under, its similarities to a 3-4 set, and make sense of our defensive line recruiting. For the purposes of this diary I’m ignoring the secondary. You need corners and safeties. They’re all similarly sized players, get fast ones. The front 7 is where you need guys over a 100lb range and some more major differences show up.
Here’s a base 4-3:
Here's a base 3-4:
Both of these defensive base sets have advantages and disadvantages, and both lend themselves to different styles of players. When it comes to what Michigan is running as a base defense, the 4-3 Under, recruiting starts to make sense if you look at it as a 3-4 defense.
The 4-3 Under:
First, look at the D Line from the middle out. In a 4-3 Under you have a defensive tackle on the Nose, in a 0 or 1 Technique (NT) (Technique definitions:
You then have 2 players lining up at the 3 tech (DT) and 5 tech (SDE). Then you have 2 players further out on the line, at a 7 tech (WDE) and 9 Tech (SAM). Finally, you have 2 linebackers off the line of scrimmage (MIKE and WILL).
Now, compare these positions to the 3-4 Base. You still have a huge space-eating Nose Tackle (NT) who lines up at the 0 or 1 tech, 2 Defensive Ends over the guards, tackles, or in between (4 tech... hmmm, just a slight shift from the 3 or 5 tech...) and 2 people outside of them near the line of Scrimmage (OLBs). Finally you have 2 linebackers off the line of scrimmage (MIKE and WILL).
If you look at these two defenses, the only main difference is one of your 3-4 OLBs has his hand on the ground. That’s it! There are minor shifts on the line and other intricacies, but big picture the 4-3 under has personnel requirements very similar to a 3-4.
For the 4-3 Under OR the 3-4 in your front 7 personnel you need:
1.) A Space eating Nose Tackle (or at least one who can stand up to double teams)
2011: Mike Martin
2012 Recruit: Pipkins
2.-3.) 2 players with good size who can go against guards or tackles, defend the run, get penetration and rush the passer. (3-4 DEs or 4-3 Under 3 and 5 Techs)
2011: Heininger and RVB
2012 Recruit: Strobel, Wormley, Godin
4.-5.) 2 players with speed who can set the edge, keep contain, rush the passer, and drop into coverage occasionally (3-4 OLBs or 4-3 Under WDE and SAM. In the 4-3 Under 1 will rush the passer more often, 1 will drop into coverage more often, but both do both)
2011: Craig Roh and Jake Ryan
2012 Recruit: Ojemudia and (I can’t remember which LB projects here)
6.-7.) 2 players who make tackles. Always flow to the ball, can shed blocks, cover, and make plays (MIKE and WILL)
2011: Demens and Morgon/Hawthorne/Herron Combo
2012 Recruit: Ross, Bolden, RJS and Ringer (whoever doesn’t project to SAM)
In pass rush situations, most 3-4 Teams will run their NT off the field for an extra DB, and rush 4 with their 2 DEs and their 2 OLBs. Most 4-3 teams will sub a linebacker for a DB.
Michigan subbed Heininger (not the NT, but Martin is a better pass rusher than a prototype NT) for Avery and put Ryan on the line, just like 3-4 teams do. My guess is this continues next year, we run off a DL and let Ryan put his hand down.
As far as speculation that Michigan is loading up on linebackers, SDE types, and WDE types without taking 2 huge DTs in the class because we might switch to a 3-4 base... we kind of already have a package that uses 3-4 base type personnel. In the 4-3 Under, like a 3-4, you want flexibility in your defense. The following positions are relatively interchangeable in a 4-3 Under, don’t get caught up on DT vs. DE or DE vs LB:
3-Tech DT and SDE (5-Tech)
WDE and SAM
Michigan is recruiting the right numbers for the scheme they run. These are 17-year-old guys we’re discussing with recruits. Some will get bigger, some are maxed out. Some of the WDE/SAM types will be better at coverage and will play SAM. We saw Frank Clark and Beyer make this switch this year, one was a LB, one a DE in High School, and they switched at Michigan. Some will be better pass rushers and will drop into coverage less at the WDE.
The “Glut” at SDE doesn’t exist since the 3-Tech DT is a very similar position in the 4-3 Under, so some of these guys will play there. The coaches know what they need to run the 4-3 under, and hopefully this diary provided some insight into the personnel requirements so we can somewhat understand the method to the madness.