Defense wins championships, the saying goes, and there is plenty of truth within that statement.

It's not a perfect indicator of success—just ask Iowa, and I genuinely am not saying that as a joke—but an elite defense can be the backbone of a championship-winning team. The last decade is loaded with proof.

Alabama built a dynasty on stubborn defenses, and Georgia has done the same. Michigan won a title in 2023 because of it, too.

These picks are focused on production and efficiency with a nod to competition level.

7. 2022 Iowa

Key Players: LB Jack Campbell, S Kaevon Merriweather, DB Cooper DeJean, CB Riley Moss, DL Lukas Van Ness, DL Deontae Craig, LB/DE Joe Evans, DL Noah Shannon, DL John Waggoner, DL Logan Lee

The best compliment I can give is that Iowa surrendered 54 points in a blowout loss to Ohio State and it wasn't the defense's fault.

No, seriously.

For the season, Iowa surrendered nation-low marks of 4.0 yards per play and 13.3 points per game.

Though the team finished 8-5, that included two losses where the defense gave up 10 points or fewer. Opponents only converted 30.6 percent of third downs and scored touchdowns on just 41.2 percent of red-zone trips.

Ohio State rolled to a 54-10 win, yes. Iowa, however, committed six turnovers and three on downs. Ohio State actually only mustered 360 yards, but Iowa's inability to play offense—a frustrating trend in recent years—plagued the Hawkeyes in disastrous fashion that day. (Oh, by the way, the defense scored Iowa's lone touchdown in the game.)

Unlike most other teams, a dominant unit wasn't enough to salvage this Iowa squad. But, man, this defense was incredible.

6. 2023 Michigan

Key Players: DL Kris Jenkins, LB Junior Colson, LB Michael Barrett, DL Jaylen Harrell, DL Braiden McGregor, DL/LB Josaiah Stewart, DE Derrick Moore, DB Mike Sainristil, DB Will Johnson

Do you want to have the sign-stealing conversation? That's a piece of the discussion around 2023 Michigan. But, honestly, I'm not concerned about it, given how the Wolverines kept thriving in the aftermath.

As the Wolverines cruised to 9-0, they ceded a mere 60 points—a hilarious 6.7 per outing, if you're doing the math.

The scandal broke out. Jim Harbaugh served a three-game suspension, and Michigan gave up 15 points to Penn State, 24 to Maryland and 24 to Ohio State. He returned in time for the postseason; Michigan blanked Iowa in the Big Ten Championship and held Alabama and Washington to 33 combined points in the College Football Playoff.

Elite defense, no matter the context.

The champions went 15-0 with a defense that ranked first nationally in scoring (10.4) and yards allowed per game (247.0) and fourth in yards allowed per play (4.3). The unit snagged 18 interceptions while opposing teams totaled 17 touchdowns all season.

5. 2019 Georgia

Key Players: S J.R. Reed, DL Travon Walker, DL Quay Walker, DL Tyler Clark, DL Azeez Ojulari, DL Jordan Davis, LB Tae Crowder, CB Mark Webb, CB Richard LeCounte, CB Lewis Cine

Still searching for a championship in 2019, Georgia ran into the LSU buzzsaw and fell annoyingly shy of a CFP berth. Part of that can be attributed to an offense that lacked an explosive element.

Along the way, though, the defense just rolled.

None of UGA's regular-season opponents topped 20 points as the Dawgs upended four Top 25 teams. Georgia ceded a single rushing touchdown and posted three shutouts on the path to 11-1.

LSU breezed to a 37-10 rout in the SEC title game, and UGA's defense can shoulder some blame for it. As with 2022 Iowa, however, it's tough to criticize when the defense held an LSU juggernaut to 20 points through 40 minutes as the offense stumbled again and again.

In the final rankings, Georgia was first in scoring defense (12.6), second in yards per play (4.3) and third in explosive plays allowed (11).

4. 2018 Clemson

Key Players: DL Christian Wilkins, DL Clelin Ferrell, DL Dexter Lawrence, DE Austin Bryant, DL Xavier Thomas, S/LB Isaiah Simmons, S Tanner Muse, CB A.J. Terrell, CB Trayvon Mullen, S K'Von Wallace

The peak of Clemson's powers arrived in 2018 as Trevor Lawrence and an overwhelming defense led a perfect year.

Complemented by a high-scoring offense, this defense didn't need to carry the Tigers. Considering the unit allowed 16 points or fewer in 11 of the team's victories, it could have anyway.

There's hardly a better way to summarize the excellence than opening the national championship with a pick-six.

But I'll try!

Clemson, which finished 15-0, paced the nation in scoring defense (13.1), tackles for loss (136) and sacks (54), ended second in yards allowed per play (4.2) and registered top-five marks in both third-down and red-zone touchdown percentage.

3. 2016 Alabama

Key Players: LB Reuben Foster, DB Ronnie Harrison, DB Minkah Fitzpatrick, DL Jonathan Allen, DL Dalvin Tomlinson, LB Rashaan Evans, LB Ryan Anderson, LB Tim Williams, DB Anthony Averett, DB Marlon Humphrey, DL Daron Payne, DB Eddie Jackson

Rutgers scored 19 touchdowns all season, and UTSA managed a nation-low 18. Alabama's defense, meanwhile, found its way to the end zone on 11 occasions in 2016.

That comparison doesn't feel possible. Nevertheless!

Alabama stood atop the country in scoring defense (13.0), sacks (54) and both yards allowed per play (4.0) and per game (261.8). The unit corralled more interceptions (16) than passing scores allowed (15).

Eight defenders had a touchdown for Bama, which survived a high-scoring affair with Ole Miss in September but otherwise ceded more than 16 points once en route to an appearance in the national championship. Clemson won that matchup 35-31 with a memorable last-second score.

That finish, however, should not overshadow a fantastic season from the Crimson Tide's defense—one that boasted four AP All-Americans.

2. 2017 Alabama

Key Players: DB Minkah Fitzpatrick, DB Ronnie Harrison, LB Rashaan Evans, LB Mack Wilson, LB Anfernee Jennings, DL Quinnen Williams, DL Raekwon Davis, DL Isaiah Buggs, DL Daron Payne, DL Da'Shawn Hand

One year later, Alabama earned its redemption.

Look, if you prefer the 2016 group, no problem. We are splitting hairs between these defenses, and the 2017 Crimson Tide hoisted the championship trophy at season's end.

Alabama again led the country in scoring defense (11.9), yards per play (4.0) and per game (260.4). Additionally, opponents tallied the fewest gains (13) of 30-plus yards. Moving the ball—or trying to, at least—was a nightmare against this Alabama squad.

Although a loss to Auburn prevented the Tide from making the SEC Championship, they rebounded in the College Football Playoff.

First, the defense held Clemson to 188 yards in a 24-6 victory. Alabama then limited Georgia to 365 yards and played a critical part in keeping the game tight enough to set up Tua Tagovailoa's second-half and overtime heroics in a 26-23 triumph to win a national title.

1. 2021 Georgia

Key Players: DB Lewis Cine, LB Nakobe Dean, LB Channing Tindall, LB Quay Walker, LB Nolan Smith, LB Robert Beal, DL Jordan Davis, DL Travon Walker, DL Jalen Carter, DL Devonte Wyatt, DB Christopher Smith, DB Kelee Ringo

From beginning to end, Georgia suffocated its competition—save for a blip in the SEC Championship Game.

That day in December, Alabama poured on 41 points to secure the conference crown and a spot in the CFP. Georgia wanted the SEC title, of course, but effectively had a Playoff trip locked up. And then, the Dawgs took full advantage of that championship opportunity.

But first, the regular season.

Georgia held all 12 opponents to 17 points or less, including three shutouts and four Top 25 victories. The defense responded in the CFP, holding Michigan to 11 points and Alabama to 18 in the national title.

Along with a slew of top-10 rankings, UGA surrendered a nation-best 10.2 points per game and 28.1 red-zone touchdown percentage.