Back by overwhelming demand, FootballScoop will once again examine the assistant coaching hires that will have the biggest impact on the college football season and the coaching job market in the 2019 season and beyond.

No. 19: Bryan Brown, Louisville

No. 18: Phil Longo, North Carolina

No. 17: Les Koenning, Kansas

No. 16: Andy Avalos, Oregon

No. 15: Joe Cauthen, Houston

No. 14: Bodie Reeder, North Texas

No. 13: Mike MacIntyre, Ole Miss

No. 12: Andy Ludwig, Utah

No. 11: Kenny Dillingham, Auburn

No. 10: Jim Chaney, Tennessee

No. 9: Sean Gleeson, Oklahoma State

No. 8: Dan Enos, Miami

No. 7: Kendal Briles, Florida State

No. 6: Jeff Hafley and Greg Mattison, Ohio State

No. 5: Steve Sarkisian, Alabama

No. 4: Joe Brady, LSU

No. 3: Graham Harrell, USC

Who: Alex Grinch, Oklahoma

Title: Defensive coordinator/safeties coach

Previous stop: Ohio State co-defensive coordinator/safeties coach (2018)

Why he’s important: Since 2005, FBS teams are 408-3,806 when allowing 40 points or more, good for a winning percentage of .0968, according to data provided to FootballScoop by SportSourceAnalytics. Since hiring Lincoln Riley, in 2015, Oklahoma is 9-4, winning at a clip just below 70 percent.

So while the rest of college football is basically Rutgers when giving up 40, Oklahoma is still an 8-win team. Depending on what conference you’re in, that’s good enough to get you into a New Year’s Day bowl game.

Needless to say, that’s insane. It’s also unsustainable, which is why Grinch traded scarlet for crimson in January.

While it’s easy to squint and see Oklahoma winning a national championship with even slightly competent defense in either of the past two seasons — especially the 2017 team, that led Georgia 31-14 late in the first half and held a lead into the final minute of the fourth quarter and had the ball with a chance to win the game in regulation and overtime — it’s equally easy to imagine where this program would be without A++++ level offense.

Last year’s team surrendered an average of 47.3 points over its final four games (and won all of them). They trailed Texas Tech 31-28 at halftime, in Lubbock, when Tech quarterback Alan Bowman got hurt. They were a 2-point pass away from losing to Oklahoma State. They gave up 40… to Kansas… at home. They gave up 56 points and 704 yards to West Virginia, and the pivotal play of the game came when one of its defensive backs was blocked so far out of bounds that WVU was hit with a 15-yard penalty.

West Virginia had a big run called back because T.J. Simmons kept blocking an Oklahoma DB out of bounds…. And two plays later, Will Grier fumbled, Oklahoma took it back for a TD. Brutal! pic.twitter.com/eseIz4cwaB — '04 Rabih Abdullah (@ftbeard_17) November 24, 2018

All this to say, where is Oklahoma with, say, Honorable Mention All-Big 12 play from Baker Mayfield and Kyler Murray over the past two seasons? Are we talking about a 6-6 football program?

Grinch was hired to make that a moot question, and secondary is a good place to start because he’s ripping out what was planted before him by the root.

“We’re very, very thin in the secondary, which is alarming, just from a depth standpoint,” Grinch told The Oklahoman in March. “We’ve got some young guys coming in the fall we’re gonna have to plug in.

“I’d probably echo that maybe across the board, probably a little bit more thin than we should be at Oklahoma, but that also is a great opportunity for guys to get reps.”

Grinch’s vision for the future of Oklahoma’s secondary can be seen on the Sooners’ 2020 commitment list, where their two current commits stand 6-foot-2 and 6-foot-2.5. Seven of the eight members of OU’s defensive backfield two-deep in 2018 stood between 6-foot even and 5-foot-9. Which means, for now, Grinch is going to have to make chicken salad out of… some bad, old chicken salad.

“Don’t ever say you never had a chance to play at Oklahoma because right now, whether you’re a walk-on, whether you just thought you were just gonna get a jersey and a couple square meals on a Friday before a game, you’ve got a chance to get reps out here and you’d better take advantage of it,” Grinch said.

“I don’t see a fast defense yet. I don’t see a brand of football that would put us anywhere close. Certainly not an elite defense, but I wouldn’t even make a claim (to) the top half of the country,” he told the Tulsa World in April.

Of course, the tried and true way to protect an overexposed defense is to get them off the field as fast and as often as possible, either by winning on third downs, by forcing turnovers, or both. And on that front, Riley has hired the foremost expert on the topic.

Prior to Ohio State, Grinch coordinated Mike Leach’s defenses at Washington State from 2015-17. Here’s a chart of how Wazzu’s defense improved under Grinch’s watch, examining the defense he inherited to the one he left.

Wazzu D, pre- and post-Grinch 2014 2017 Yards Per Play 6.18 (103rd) 5.13 (34th) Pass Efficiency Defense 158.01 (124th) 109.09 (7th) Third Down Defense 39.31% (59th) 28.49% (4th) Takeaways 8 (t-127th) 28 (t-9th)

“We kind of coined the phrase, ‘Takeaways equal victory,'” Grinch said at his introductory press conference in January. “It stems from the fact that the sole purpose of the defense to be on the football field is to get the football back to the offense… The purpose behind every play in football is for the defense to get the ball back to the offense. The ball doesn’t know it’s supposed to go from the quarterback to the receiver, it doesn’t know it’s supposed to stay in the arm of the running back. So if the ball doesn’t know, then how on earth do we know? That gives us every opportunity on every snap to get the ball back.”

The good news here is buy-in hasn’t been a problem. Oklahoma’s defenders are as tired of the labored exhales, the “Here we go again” grumbles as anyone. “They want to be so much better. God, they want to be so much better,” Grinch told the OU Daily on Monday. “The buy-in, I can’t even describe to you.”

In addition to losing Kyler Murray, Oklahoma has to replace four starting offensive linemen and All-American wide receiver Marquise Brown. As long as Riley is recruiting the players and calling the plays OU will always be good or very good on offense, but what happens if they’re no longer, you know, the most efficient and explosive offense in college football history? How much better does the defense have to get if the offense drops from a 99 to a 92? If that happens and the defense doesn’t improve — look out.

On the flip side, what if this works? Riley and Grinch could be a match made in football heaven. Two dudes in their 30s raised on opposite ends of the football spectrum — Riley grew up in offense-first Texas, Grinch in defense-first Ohio; Riley was reared under Mike Leach, the godfather of the Air Raid, Grinch under the bluest of blue collared Vince Kehres; Riley falls asleep dreaming of new mesh concepts and trick plays hidden inside of trick plays, Grinch wakes up at 2 a.m. and pours rusted nails into his cereal, which substitutes milk for motor oil.

Oklahoma president George Cross once stood before the state legislature and pleaded for funding by saying, “I would like to build a university which the football team can be proud of.” If Grinch can build a defense the offense can be proud of — look out. The Oklahoma dynasty that reigns over the Big 12 will expand east, planting a crimson and cream flag over Tuscaloosa, Athens and Clemson.