When a program can find the right kind of defensive linemen, the 3-4 is one of the great equalizers in college football. The defense can use faster players, disguise blitzes to give pass rushers easier paths to the QB and more easily shift around to outnumber whatever the offense does best.
Lots of smaller programs love to go the 3-4 route, be free of the need to find great pass-rushing defensive ends and just load up on smaller athletes who are easier to find and recruit.
For the last several years, the Oregon defense has been a paradox, a 3-4 loaded with phenomenal linemen like DeForest Buckner, but lacking in playmakers at linebacker or defensive back.
It was only 2012 when Oregon's defense was at its zenith, ranked No. 2 in defensive S&P+ and led by superstar inside-backer Kiko Alonso. The Ducks were winning over folks who thought they were just about offense.
Alonso departed for the NFL and they understandably slipped to No. 25. In 2014, longtime DC Nick Aliotti retired and LB coach Don Pellum was promoted. With a veteran group of defensive backs who helped Oregon go plus-23 in turnover margin, Pellum's first year saw just a minor slip to No. 28.
Then Oregon lost three-fourths of its secondary, four-fifths of its nickel lineup and went over the cliff, finishing No. 82 and closing out 2015 by surrendering a 31-0 lead to a TCU offense playing without Trevone Boykin, Josh Doctson or several starting offensive linemen.
The 2015 defense was error-prone and did not get much playmaking from the linebackers. Tyson Coleman led the LBs with only 4.5 sacks. Potential top-10 2016 NFL Draft pick Buckner did the heavy lifting for the pass rush from various spots across the defensive line.
Head coach Mark Helfrich's solution to an undisciplined defense that struggled to maximize good DL play? He hired former longtime defensive line coach and Michigan head coach Brady Hoke to install his 4-3 scheme. While the Wolverines fell to 5-7 in Hoke's last year, three of his four UM defenses ranked in the S&P+ top 30.
Hoke is a big fan of the 4-3 under defense, aggressive single-gap DL play and aggressively pressuring the offense with eight-man fronts and heavy blitzing
Each is a departure from Oregon's 3-4, though not markedly different from the style under Aliotti before the 3-4 switch.
By shifting linemen to the weakside (the side with fewer run blockers), the 4-3 under relies on stout play at the strongside end and nose tackle positions and effective contain play from the strongside "sam" linebacker. Those three are marked here:
The under defense has had to fight to survive in an era of spread offense. It was originally designed to stuff two-back offenses like the I formation.
This base package will come in handy against the conventional Stanford and USC, but Oregon will be facing spread teams that will require nickel sub-packages and aggressive safeties to account for run gaps.
In general, this system isn't shy about dropping a safety on the weakside to clean up the cutback lanes and allow the linebackers to race to the ball without fear of giving up a hole.
Dropping eight defenders into coverage or playing conservative, four-deep coverage without run responsibilities for the safeties? Oregon's days of doing that are over
Instead of looking to contain the defense with the outside linebackers while the safeties drop deep or fill the alley as needed ...
... Oregon will contain the ball with an eight-man front and force outside runs with the down safety ($) or perhaps with defensive ends, depending on what Hoke picked up from his time with the Clemson staff (in 2015, Clemson used DEs to force the run inside, thus protecting their defensive backfield).
Good defenses force opponents to play in limited spaces, particularly in a spread era when offenses excel at getting the ball to fast people in open grass. The Ducks had tons of good schemes for containing opponents in 2015, but they weren't executing them. They weren't getting playmaking from the defensive backfield to allow their "bend don't break" style to hold up.
Will this work at Oregon?
When you emphasize aggressive line play, fast-flowing linebackers, a safety in the box and increased blitzing, someone on the defense has to be able to pick up the check.
That will fall largely on the cornerbacks, who have been good in the past at Oregon but were too young to be a team strength in 2015.
In addition to conservative quarters defense and some safer versions of cover 3, the Ducks have made cover 1 (man coverage) a big part of their formula over the years. Hoke isn't bringing anything new to Eugene, simply a new point of emphasis. The Ducks want to run fewer coverages better.
But given Oregon's lighter recruiting at CB over the last few years, Helfrich might want to give up some athletes Oregon intended for offense in order to get enough speed in the secondary to make this work.
The strongside end and tackle vacancies should find interesting applicants from Oregon's store of tall, athletic 3-4 DEs. 2015 five-star signee Canton Kaumatule and many current linemen should fit the new style. They may enjoy the freedom to get up the field, rather than grappling with offensive linemen in two-gap techniques. Many defenses converting to under fronts worry about having a DT or DE who could hold the point of attack. This isn't likely to be an issue for the Ducks.
On the weakside, Oregon's cast of lanky pass-rushers shouldn't find the new assignments terribly different. Things should be simpler, if occasionally more physical.
At safety, the Ducks have a fair amount of experience, including two-year starters Reggie Daniels and Tyree Robinson. Long-term, it'll be interesting to see if Fotu Leiato, the player who went from unknown to star recruit thanks in part to his viral film of huge hits, can thrive as a box safety running to the football.
Of course, philosophical changes are often doomed or blessed by what happens behind closed doors. Pellum has to step down from DC and embrace teaching a new style under Hoke's direction while overseeing the linebackers who will be set up to be playmakers.
Based on 2015's struggles and the word choices coming out of Eugene, the goal of the Hoke hire was not to overhaul the Ducks (although that's happening) but to get more organization and quality control
Implicit in that line of thinking is that Helfrich felt Pellum lacked an eye for details. Hoke definitely has an eye for defensive detail and strong feelings about building a culture on defense. He's on the record that running a strictly spread offense makes it hard to foment a physical defensive culture. How that jives with Oregon's up-tempo spread remains to be seen.
Hoke also brought a physical playbook to Eugene, rather than emphasizing digital media, bucking Oregon's embrace of modern trends designed to suit the younger generation. Hoke is going to emphasize classic football, an interesting counterpart to Helfrich's thoroughly modern offense.
If the staff is on board with that vision (it probably is) and Helfrich can work with a coach who's used to having his way at an even bigger program, the Ducks might have found a new solution to the problem faced by many spread offenses: how to pair it with a physical defense.