There’s no better way to explain it: Iowa played with what amounted to a fullback at quarterback for a majority of the 2023 season.

And Phil Parker’s defense was still among the best in the nation and the backbone of a remarkable 10-win season.

Iowa finished with 1,232 more punting yards than total yards (4,516 to 3,284) and averaged 15.4 points per game behind bowling ball quarterback Deacon Hill (6-3, 260 pounds). In its 4 losses, Iowa averaged — this is not a misprint — 2.5 points per game.

Now imagine coach Kirk Ferentz looking at Parker, his longtime DC and close friend, and telling him to go win the game. Which the defense usually did, week after week.

The Hawkeyes gave up 14.8 points per game, and allowed 20 TDs (No .4 in the nation) — despite being pushed into untenable situations with a putrid offense game after game.

If Iowa ever regains its offensive footing, a Playoff bid becomes all the more realistic. All thanks to Parker, 1 of the Top 25 defensive coordinators in the nation in 2024:

No. 25 Brian Knorr, Air Force

The former Ohio coach has spent more than 3 decades in college football and is doing his best work with the Falcons. In 2 seasons as DC, his teams have finished 3rd (13.4 ppg.) and 12th (18.2 ppg.) in the nation in scoring defense.

No. 24 Al Golden, Notre Dame

Rejuvenated his coaching career the past 2 seasons with his work as the Irish DC. Those disastrous Miami years are long in the rearview. Notre Dame was 7th in the nation in scoring defense in 2023 (15.9 ppg.) and gave up only 23 TDs (5th in the nation).

No. 23 Chris Marve, Virginia Tech

A fast riser in the profession, this could be a critical season in his development. The Hokies are loaded and are a sleeper Playoff team. A big season could translate to a Power 5 coaching job (see: his alma mater, Vanderbilt).

No. 22 Kane Wommack, Alabama

Left his head coaching job at South Alabama for a better gig coaching the Alabama defense — and a faster track to reaching a Power conference head coaching job. His strong work as the Indiana DC got him the South Alabama job. Success at Alabama will come with much greater opportunities.

No. 21 Tom Allen, Penn State

A steal of a hire for Penn State coach James Franklin. Allen could have sat out and relaxed with millions from his firing at Indiana. Now Penn State gets a DC with a history of creating turnovers and pressure defenses — with head coach history. Look beyond the numbers: Penn State allowed just 13.5 points per game last season, but the Lions gave up twice that against the 3 best offenses they faced.

No. 20 Tim Banks, Tennessee

The blueprint has always been there, from his days at UCF. The recruiting of coach Josh Heupel and his staff has allowed it to play out on the field. The more the roster upgrades, the more dangerous the defense becomes. And it made huge strides last season, allowing 20.3 points per game.

No. 19 Ron English, Louisville

Since the mid-1990s, English has coached at 11 schools and has been one of the game’s top secondary coaches. The defense was the foundation of Louisville’s 10-win season in 2023, even though it struggled in the last month of the season.

No. 18 DJ Durkin, Auburn

Look at the resume: DC at mega programs Florida, Michigan, Ole Miss, Texas A&M and now Auburn. His recruiting and development built the Texas A&M defense into a monster along the front four under Jimbo Fisher. Just like he did at Florida, and the same thing he’ll do at Auburn.

No. 17 Joe Klanderman, Kansas State

Followed Chris Klieman from North Dakota State to K-State, and has had opportunities to leave Manhattan. Has had a top-40 defense in each of the past 3 seasons, and his secondary has 40 INTs over that span.

No. 16 Wes Goodwin, Clemson

It wasn’t long ago that Clemson coach Dabo Swinney was criticized for Goodwin’s move from defensive assistant to DC in 2022. We now have 2 seasons of empirical evidence — and it looks good. Top 30 defenses in 2 seasons, and the same aggressive style that fueled the Tigers’ championship runs.

No. 15 Jon Heacock, Iowa State

The classic case of more with less. Iowa State isn’t among the top recruiting schools in the Big 12, much less the nation. But Heacock’s units have for years been among the best in the league and the nation. Even last year’s fall to 44th in the nation (22.8 ppg.) is a win for most Power conference teams.

No. 14 Mike Tressel, Wisconsin

His past 3 defenses — at Cincinnati (2021-22) and Wisconsin (2023) — finished 5th, 20th and 21st in the nation in scoring defense — and forced 71 turnovers. That’s how you win big games. This Wisconsin defense has top-10 potential.

No. 13 Pete Kwiatkowski, Texas

A top-15 defense at Texas (18.9 ppg.), in the Big 12, is an impressive number. That followed a 2022 defense that was top 30. He defenses have been part of conference championships at Boise State, Washington and Texas — and have reached the Playoff twice (2016 with Washington and 2023 with Texas).

No. 12 Pete Golding, Ole Miss

Golding never got the credit he deserved for his work at Alabama. Anyone in that job is compared to both Nick Saban and Kirby Smart. A lose-lose all around. Ole Miss improved to 57th to 44th in the nation in scoring defense (22.5 ppg.), and the talent this season is the best it has been under coach Lane Kiffin.

No. 11 Tosh Lupoi, Oregon

A 3-year exile in the NFL ended when Oregon coach Dan Lanning named him DC in 2022, and the Ducks’ defense struggled in 2022. Last year, the unit dramatically improved: from 27.4 ppg in 2022, to 16.5 in 2023 — finishing 9th in the nation in scoring defense. Oregon also improved from 115th to 29th in the nation in sacks (34), and from 123rd to 37th in 3rd-down defense (35.8%).

No. 10 Joe Rossi, Michigan State

Arguably the best coordinator hire of the offseason. Many coaches tried to get Rossi to leave Minnesota over the past 5 years, and only new coach Jonathan Smith — who had never coached in the Big Ten and knew nothing of the league — got it done. Rossi led top-6 defenses in 2021-22, despite limited offensive production.

No. 9 Morgan Scalley, Utah

Scalley added the title of coach in waiting this offseason, a smart move for a program built on consistency. Scalley’s defenses, with the foundation of coach Kyle Whittingham’s defense-first philosophy, dominated the last 3 years of the Pac-12 and are consistently among the nation’s leaders in explosion plays (sacks, forced turnovers).

No. 8 Wink Martindale, Michigan

If you’re elite in the NFL, you’re elite in college football. It’s still about teaching and developing — though there will be subtle difference that could take time to embrace (linemen blocking up to 3 yards beyond the line of scrimmage). Can Martindale’s first defense be as good as last season’s under Jesse Minter? Michigan led the nation in scoring defense last season, allowing just 10.4 points per game. They allowed just 3 TDs combined in Playoff wins over Alabama and Washington en route to winning the national title.

No. 7 D’Anton Lynn, USC

No DC in the nation is under a bigger microscope. Like it or not, fair or not, Lynn is expected to turn a beaten-down USC defense into what UCLA looked like last season. How far does he have to go? Simple, 16 points: UCLA was 14th in the nation in scoring defense in 2023 (18.4 ppg.); USC was 121st (34.4).

No. 6 Adam Fuller, Florida State

It took 2 seasons, but Fuller has the FSU defense back among the nation’s elite with back-to-back top-20 finishes in scoring defense in 2022-23. It should come as no surprise that his rise has coincided with FSU’s rise in the ACC and back among the nation’s elite. Talent increases, performance increases.

No. 5 Tony White, Nebraska

If it weren’t for the inept Nebraska offense in 2023, we’d know more about the elite Nebraska defense. The Huskers were 13th in the nation in scoring defense and 11th in total defense — despite being 132nd out of 133 teams in turnover ratio, a whopping negative-17. They’ll be even better in 2024.

No. 4 Jim Knowles, Ohio State

Hiring Knowles was Ohio State coach Ryan Day’s first move to catch Michigan, and Knowles has done everything right — but it hasn’t been enough in the 1 game that matters. The Buckeyes went from No. 24 in the nation in scoring defense in 2022, to No.2 in 2023 (11.2 ppg.). No one has more defensive NFL talent. Georgia won it all behind its defense in 2021; can Ohio State do it in 2024?

No. 3 Blake Baker, LSU

The highest-paid defensive coordinator in the nation ($2.5 million per year). Former LSU assistant left for Missouri, and proved he could run an elite SEC defense. Now it’s time to return to the Bayou, and rescue an historically bad LSU defense.

No. 2 Glenn Schumann, Georgia

From Dan Lanning to Will Muschamp to Glenn Schumann. Georgia has had 3 of the best defensive minds in the game as the backbone of its rise to the nation’s elite — with defensive-minded HC Kirby Smart at the forefront. Schumann, like Smart did at Alabama and like Lanning did in Athens, will stay at Georgia until he gets the perfect HC job offer.

No. 1 Phil Parker, Iowa

Think about this number: Iowa punted 93 times in 2023. Georgia punted 32 times. Georgia won 13 games; Iowa won 10. It’s unfathomable what the Iowa defense was asked to overcome — and Parker did.