Returning defensive production numbers are based on weighting methodology for all defensive positions and the % returning players that contributed to measurable statistics at those positions. Transfers not accounted for.
A few thoughts:
1. The B1G as a whole has 8 teams that are in the bottom 1/3 of all of NCAAF in returning production. There will be new faces scattered across many defenses in the Midwest this year. This makes defensive talent/depth and a proven process of reloading players more important this year in the B1G than in most. I would expect teams that have had multiple years of solid recruiting classes like Michigan and Penn State, along with Wisconsin who has had years of successful continuity on Defense to handle to this transition year better than the others. Programs like Minnesota, Nebraska and Illinois, all who finished as Top 30 Ds in '21, may have more trouble replacing the talent/experience.
2. Indiana's an example of the classic, "yes you have experience, but its bad experience". Indiana's defensive efforts didn't cut it in '21 granted they were hardly helped by their sad, sad offense. HC Tom Allen is returning to his roots by taking over playing calling for the defense after he relinquished those duties. McFadden, the heart & soul of the IU D over recent years, will no doubt be hard to replace but the Hoosier secondary could/should be one of the best in the conference with returnees Mullen, Matthews & Williams holding it down. Veteran LB Cam Jones and Transfer Bradley Jennings should be solid in the middle, the degree of improvement from this D will depend on who/how many can step up along the D-Line.
3. Ohio State & Michigan State have reason for optimism after their defenses cost them each a couple of games last year. OSU struggled to stop the run and MSU struggled to stop the pass. However, both will be much more experienced this upcoming year and while OSU's defensive depth chart is littered with 5 & 4 stars, MSU will field a talented unit as well, especially up front with D-Lineman Slade, Hansen, Barrow & Bogle.
4. Iowa is poised to have the best LB core in the conference and possibly the best Front 7. Led by Jestin Jacobs and Jack Campbell, the Hawkeyes bring back all 3 starting LBs from last years #5 Defense and their D-Line should take another step forward this year with the services of Luke VanNess, Joe Evans & Noah Shannon.
5. Purdue is getting some pre-season love for the 1st time in a long time but mainly because of O'Connell and their O. Don't sleep on their D as they were sneaky good last year and bring back some key pieces in the likes of DL Kydran Jenkins, LB/S Jalen Graham and S Cam Allen.