The turnaround for the Virginia football team under Coach Bronco Mendenhall includes a defense ranked third in the ACC this season after finishing last the year before he took over the program. (Chris Seward/Associated Press)

CHARLOTTESVILLE — Virginia football Coach Bronco Mendenhall was hosting a recruit recently when the two began discussing the Cavaliers’ defense. Mendenhall recalled detailing the multiple alignments and personnel groups he deploys in each game and the football IQ he expects from all of his players within that unit.

The primer into the intricate concepts of a coach considered a defensive mastermind left the recruit somewhat overwhelmed.

“I think his comment was, ‘This is not a dumb guy’s defense,’ ” Mendenhall said. “Listening to the vernacular and the identity changes and the shifts and trying to keep up with it, and it’s true. But it’s also U-Va., which fits perfectly. These are bright, talented, smart kids, and we ask a lot of them from a cognitive standpoint.”

Nearing the conclusion of his third season at Virginia, Mendenhall has already clinched an improved record in consecutive seasons by emphasizing a defensive philosophy that continues to evolve but remains rooted in principles established at Brigham Young.

Mendenhall served as the Cougars’ head coach from 2005 to 2015, consistently producing some of the stingiest defenses in major college football despite a dearth of five-star recruits. He averaged nine wins in 11 seasons at BYU. Still, when he arrived in Charlottesville in December 2015, there were significant questions about whether he could thrive in the Power Five, with a far different recruiting base.

This season, the Cavaliers are ranked third in the ACC in total defense (326.6 yards per game allowed) and scoring defense (20.6 points per game). Virginia had finished last in the conference in both categories the year before Mendenhall took over the program. At 7-4 overall, the Cavaliers are bowl eligible in consecutive seasons for the first time since 2002 to 2005; they will finish this year at .500 or better in ACC play for the first time since 2011.

The next assignment for the surging Cavaliers defense comes Friday afternoon in the 100th edition of Commonwealth Cup showdown with Virginia Tech, this time at Lane Stadium. Virginia has lost 14 in a row to its contentious in-state rival, the longest streak by either side in series history.

“It always starts with will before skill,” said Cavaliers inside linebackers coach Shane Hunter, who has been an assistant under Mendenhall for six years after playing for him at BYU. “That’s one thing that will never change regardless of where he’s at. That’s who he is. Earned not given, all those things, it all starts with defense.”

Mendenhall’s time with the Cougars began in 2003, when he became defensive coordinator and installed a 3-3-5 as his base alignment. He had been using the relatively uncommon 3-3-5 at New Mexico for several seasons as the Lobos’ defensive coordinator.

The formation requires an abundance of depth and skill in the defensive backfield, but, according to Mendenhall, BYU was not landing those players frequently enough for the 3-3-5 to function at peak levels.

That reality triggered a move to a 3-4 alignment, the current base formation at Virginia, with significant influence from the principles of Dick LeBeau, a member of the Pro Football Hall of Fame and among the most revered defensive minds in the history of the sport.

Mendenhall’s arrival at Virginia — and the ACC — allowed him and his staff to recruit more athletic players in the defensive backfield than at BYU, so he reincorporated elements from previous iterations of his defense, including at times playing 3-3-5, 4-2-5 and 3-4 all in a one game.

“I don’t think much has changed in terms of core philosophy,” said Virginia defensive line coach Vic So’oto, who played for Mendenhall from 2007 to 2010. “It’s an effort-based defense regardless of how much ability you have, and sometimes it rubs guys the wrong way. Most of the time guys take off in this system.

“Really effort and physicality are the mainstays of Coach Mendenhall’s defenses. I think the best thing about this defense is it molds to the players. We do a lot of different things now that we didn’t do back at BYU because we didn’t have DBs who could cover like our DBs can now with our secondary being so strong.”

Two players in the secondary who have thrived in particular under Mendenhall’s tutelage have been junior cornerback Bryce Hall and senior safety Juan Thornhill.

Hall leads the nation with 21 passes defended, including 19 pass breakups, two of which came in the Cavaliers’ 30-27 overtime loss at Georgia Tech this past Saturday. Hall’s second pass breakup of the game came on third and eight in overtime, forcing the Yellow Jackets to attempt a field goal.

Thornhill’s five interceptions are tied for fourth in the country. He had two interceptions to spark the Cavaliers’ first win against a ranked opponent in four years, a 16-13 victory over then-No. 16 Miami on Oct. 13 at Scott Stadium.

“To this point, I would argue that, over the three years, we’re dialing it in tighter and tighter and becoming more effective and innovating more and more to who we currently have,” Mendenhall said. “Now that we’ve seen the ACC and we have more knowledge of our opponents, we’re more effective each and every week.”

Read more:

The nation’s top running back recruit is changing positions. ‘Smart guy,’ says Adrian Peterson.

As Maryland nears end of storm-filled season, its freshmen offer rays of hope

Four straight college football seasons were ruined by injuries. What kept him coming back?

College Football Playoff rankings: UCF’s ascent livens up an otherwise stagnant upper tier

The four key questions that could decide the College Football Playoff field

Les Miles resumes his career at Kansas, the land college football forgot