When he was hired based off stats — yes, just stats — Michigan defensive coordinator Don Brown was a relatively unknown commodity in the world of college football. Those in New England knew of Brown, who was crowned “Dr. Blitz” once he signed with Michigan in 2016. The year prior, he had the No. 1-ranked defense in college football with Boston College.

Michigan coach Jim Harbaugh looked up who the top-ranked defense was and immediately hired Brown to replace DJ Durkin. Harbaugh once told the story during a press conference a few years back. But that’s how it went. Kind of like how he hired offensive coordinator Josh Gattis off a simple phone call.

Anyway, back to Brown.

At first glance, Brown’s system seemed to work wonders. Michigan had the personnel to carry out the tasks and it was winning games due to its stifling defense against both pass and run. For 4 straight years, it was top-12 in total defense. It had NFL-level talent in every position group.

Through 4 games this year, UM ranks No. 79 in total defense, giving up 425.8 yards per game and 18 touchdowns. NFL talent? Well … maybe DE Aidan Hutchinson, who’s out for the rest of the year with an ankle injury.

Things have gone south for Brown.

In comparison, during the 2018 season, the Wolverines gave up 32 TDs — scoring just 29 themselves — and about 275 yards per game. Ohio State obviously put a dent in otherwise robust numbers during the final game of the season — but UM still had the No. 2 defense in college football.

A mighty defense. Old “Dr. Blitz” had things going at a rampant pace in Ann Arbor.

Then it all went downhill … and fast.

Buckeyes have Don’s number

After cranking out stars such as DE Chase Winovich, DT Maurice Hurst and CB David Long, just to name a few, Brown’s defense has been exposed at every level — especially during the past two match-ups with Ohio State and the past five games (which includes 2019’s laugher of a loss to the Buckeyes).

The 2018 and 2019 meetings with OSU — Michigan outscored 118-66 — were less-than-kind to Brown’s defense. Tuning up the Wolverines 62-39 in 2018 and 56-27 in 2019, the Buckeyes own the distinction of scoring the most points against a Brown-led UM defense. In 2019, OSU racked up 577 total yards, with QB Justin Fields leading the way with 302 passing yards. The year prior, QB Dwayne Haskins threw for 6 TDs and 396 yards — with zero INT — and RB Mike Weber ran for 96 yards and a TD.

With the exception of Michigan’s 58-6 win in Columbus in 1946 — yeah, we have to go back that far — there have never been games as lopsided in score and stats as the past pair of beatdowns served up by the Buckeyes.

No. 1 defense in the land.

“Dr. Blitz.”

A guy recently dubbed the best D-coordinator in the country …

It’s been a wild descent for Brown, who is as fiery as they come, animated, passionate and genuinely a coach who cares. But despite having a personality that players appreciate, he simply hasn’t gotten the job done during the past two seasons.

And honestly, there were games before — and sprinkled between – the 2018 and 2019 losses to OSU that gave reason for concern.

However, the past handful have been particularly alarming.

The past 5 games …

Though Michigan’s 2020 opener against Minnesota looked somewhat impressive, it still allowed 326 yards — about 75-100 more than past Brown defenses gave up — during its 49-24 season-opening victory. Michigan State put up 449 total yards during a 27-24 win, among the most ever during the rivalry series. The Hoosiers rang up 460 yards during a 38-21 win. This past Saturday, UM gave up a season-high 468 to Wisconsin.

Already mentioned, the 2019 OSU loss was a stats nightmare — the 577 yards likely caused Brown to age a few years.

2020 woes

Michigan’s secondary has been torched at every turn through 4 games. Cornerback Vincent Gray has been a favorite target for opposing QBs. MSU QB Rocky Lombardi looked like an All-Big Ten star while connecting with WR Ricky White for 196 yards and 1 TD. The following weekend, Indiana QB Michael Penix and WR Ty Fryfogle had a nice day of pitch-and-catch, connecting for 142 yards and a score.

Against Wisconsin, the Wolverines actually did a decent job defending the pass. So naturally, the No. 13 Badgers took to the ground, steamrolling for 341 yards and 5 TDs. Four Badgers ball-carriers had more than 65 yards, a first of the Brown era at UM, led by Jalen Berger, who had 87 yards and a score.

There is no real remedy. It’s too late to change schemes and start from scratch. At this point, Michigan is what it is — and that’s a team with an ineffective offense and rapidly degrading defense.

The fall of Brown’s defense is one of the biggest mysteries in college football. Former DC Greg Mattison — who jetted for Ohio State two years ago after moving to DL coach under Brown — had built a powerhouse defense. Brown was supposed to take it to new heights. Now it’s just a crumbling foundation that’s seen better days.