P.J. Fleck hears the same adjective used by rival coaches and other outsiders to describe his offense: Simple.

It's not meant as a knock, but it doesn't exactly sound like a compliment either. Fleck insists he is not annoyed by that opinion.

"Our offense is our offense," he said. "Our offense evolves every single year. We do different things every year. We're not hard to figure out."

Maybe not, but their offense has become a nightmare for opposing defenses. The Gophers rank 15th nationally in scoring at 37.6 points per game, which is on pace to finish as the second-highest scoring average for the program since 1946.

The 2003 Gophers offense led by Marion Barber III and Laurence Maroney set the program record at 38.7 points per game.

The growth from Year 1 of Fleck's tenure to Year 3, and why his team is 9-0 and ranked No. 7 in the Associated Press poll and 17th and most likely climbing in the College Football Playoff rankings, is best illustrated in the offense's evolution.

In 2017, Fleck's first season, the Gophers finished 108th nationally in scoring at 22.1 points per game.

Last season, they ranked 65th at 28.9.

This season, they are 15th at 37.6.

Translation: From one of the worst offenses in college football to among the best.

The litmus test arrived Saturday with the nation's No. 2-ranked defense, Penn State. The Gophers scored touchdowns on their first two possessions against a defense that had not given up a first-quarter touchdown all season.

They rushed for 121 yards — roughly doubling Penn State's average allowed. The offensive line won its matchup, giving up only one sack. Tanner Morgan played almost flawlessly with 339 yards passing and three touchdowns. And star receivers Rashod Bateman and Tyler Johnson ran circles around Penn State's secondary.

The Gophers have scored 28-plus points in all nine games, a program record.

"It really comes down to this: Players," Fleck said. "It comes down to players executing and mastering a system."

First, players. The talent difference on offense between Fleck's first season and 2019 is Grand Canyon wide.

Johnson and Bateman are future NFL players. They have three running backs worthy of being No. 1 on a depth chart. And Morgan is proving that he's far more than a game manager, sitting No. 4 nationally in passing efficiency.

Familiarity with offensive coordinator Kirk Ciarrocca's system represents the other critical piece. The scheme isn't new anymore. Players know it and understand it on a deeper level.

"The more you simplify it, the better chance you have of mastering it," Fleck said.

Fleck gives Ciarrocca near autonomy in running the offense. Fleck still offers input and big-picture vision and philosophy, but his day-to-day involvement has become "less and less as the years have gone on."

"I trust my coordinators 100 percent," Fleck said. "Every one of them. They've earned that."

Nittany Lions coach James Franklin crystallized the challenge in defending an offense that runs the ball as effectively as the Gophers do, combined with a passing attack that features high-level receivers and an accurate quarterback who makes smart decisions on RPO (run-pass option) plays.

"You've got to commit so much to stopping the run that you're one-on-one [in the passing game] and their receivers are really good," Franklin said postgame.

Here's another way of explaining it: The Gophers rank 17th nationally in 40-yard pass plays (11), but they also are eighth nationally in time of possession. They can be both quick-strike and methodical.

Fleck loves time of possession. That's the first statistic he checks after games, which reflects his football upbringing. Coaches that he played for and coached under emphasized physical running game. Run to set up play-action.

Fleck is 38 but considers himself an "old soul." He loves Frank Sinatra and his go-to Christmas music includes Bing Crosby and Perry Como. And he loves a strong, reliable running game.

Only four teams from Power Five conferences have run the ball more times than the Gophers' 416 attempts.

"For the most part, we've been able to run our offense the way we want to run it," Fleck said.

Some call that simple. It's also highly effective.