Like a slew of other renowned defensive-oriented minds in the NFL this century, from Dick LeBeau to Pete Carroll, Jim Johnson and Wade Phillips, Vic Fangio's performance seems to be getting better with time.

Fangio, who interviewed with Broncos executives Monday, has never been a head coach, but he just completed his 32nd season on an NFL sideline and his 34th in professional football. That season was his best; the Bears led the league in total defense as Fangio maximized a unit blessed with young talent and bolstered by the September trade for pass rusher Khalil Mack.

"He's an evil genius," Mack told NFL.com in November. "The guy knows the game in and out and he knows his players, and ultimately, he wants the best for us out there on the field, so he puts us in positions to make plays."

Mack finished with 12.5 sacks, 47 total tackles and a career-high six forced fumbles under Fangio's watch. But Chicago's defense was a collaborative effort, featuring three other Pro Bowl selections: defensive lineman Akiem Hicks, cornerback Kyle Fuller and safety Eddie Jackson. Mack, Fuller and Jackson also earned selection to the first-team All-Pro squad.

The result of their work and Fangio's diligent preparation and clever tactics was clear on the scoreboard, as Chicago allowed a league-best 17.7 points per game.

"Being a coordinator, you're playing chess and trying to make an educated guess on what the other guy is going to do," Bears cornerback Prince Amukamara told NFL.com in November. "Vic is very, very detailed in his preparation. He makes the right calls for the right situation."

Fangio's career as a defensive coordinator can be divided into two eras.

In the first, he had two four-season stints guiding expansion teams (Carolina, 1995-98 and Houston, 2002-05) sandwiching a three-year stint in Indianapolis that saw him inherit a defense that finished in the league's bottom five in 11 different metrics.

Fangio's career as a coordinator saw him open with two top-10 defenses in points allowed and total yardage allowed -- the 1995 and 1996 Panthers. Even including those, his defenses averaged around the middle of the pack in his first 11 seasons as coordinator.

A four-year stint on the Baltimore Ravens' coaching staff followed his years in Houston before he returned to the coordinator ranks under head coach Jim Harbaugh at Stanford in 2010. Fangio revived Stanford's defense, which soared from 90th in FCS in total defense in 2009 to 21st in 2010. His unit also led the Pac-10 Conference in scoring defense and powered the Cardinal to its best season in 70 years.

Fangio followed Harbaugh down Highway 101 to the 49ers in 2011, and quickly built one of the league's best defenses, as the 49ers finished in the league's top five in total yards allowed and top 10 in points and yards allowed per play during each of his four seasons there before joining the Bears in 2015.

From 1995 through 2005, Fangio's defenses had average ranks of 19th in points allowed and 21st in total yardage, yardage allowed per play and first-down rate. From 2011 through 2018, the average ranks of Fangio's defenses in those categories were ninth, seventh, 10th and ninth, respectively.

Chicago's 2018 defense was Fangio's magnum opus. The Bears led the league in seven significant metrics:

• Points allowed (283)
• Takeaways (36)
• Rushing yards allowed per game (80.0)
• Yards per play allowed (4.78)
• Yards per pass play allowed (5.29)
• First-down rate (one allowed every 3.97 plays)
• First-down rate on pass plays (one allowed every 3.58 pass plays)

Chicago was also in the league's top 10 in total yardage allowed (299.7 yards per game, third), passing yardage allowed (219.7 yards per game, seventh), yards per rush (3.78, fourth), first-down rate (one allowed every 5.06 attempts, second) and sack rate (one every 13.3 dropbacks, ninth).

"Every time I walk into his office, man, he's grinding," Bears head coach Matt Nagy told the Chicago Tribune. "He's got that remote in there and he's just writing stuff down and grinding with stuff for the game. I appreciate that."

Fangio's grind began in 1979, when he coached linebackers at Dunmore (Pa.) High School. Three more seasons as a high-school assistant followed before he spent the 1983 season as a graduate assistant at North Carolina.

Then Fangio got his big break from Jim E. Mora, coach of the United States Football League's Philadelphia Stars. Mora hired Fangio as a defensive assistant, and the Stars won back-to-back USFL titles. The league collapsed after that season, but the Stars' performance earned Mora the head-coaching job with the New Orleans Saints in 1986, and he took Fangio with him as linebackers coach.

All Fangio did over the next eight seasons was create arguably the best 3-4 linebacking quartet in NFL history: New Orleans' famed "Dome Patrol" of Hall of Famer Rickey Jackson, Vaughan Johnson, Sam Mills and Pat Swilling. The four linebackers combined for 16 Pro Bowls, six First-Team All-Pro nods and five Second-Team All-Pro selections during Fangio's nine years as their position coach.

Fangio moved to the expansion Panthers in 1995 to accept his first professional coordinator position, but he was able to take Mills with him, and together they helped the Panthers become the first expansion team in NFL history to win a division title in their first two seasons.

Carolina rocketed to a 12-4 record in 1996 on the strength of Fangio's pressure defense, which led the NFL by sacking opposing quarterbacks once every 10.3 dropbacks.

The fact that Fangio built dominant defenses in the 1990s and 2010s bodes well for his potential as a head coach, as he has successfully adapted with changing times, philosophies and points of emphasis. If hired, Fangio would become the oldest coach in Broncos history, but with his wisdom, experience and ability to maximize and relate to his on-field talent, his age is irrelevant.