Nicole Auerbach

USA TODAY Sports

Willie Fritz has coached a bunch of football teams over the course of his career, and he's now been a head coach at four different levels — from Blinn (Texas) College of the NJCAA to Central Missouri of NCAA Division II to FCS Sam Houston State to first-year transitional FBS member Georgia Southern.

At every stop, there is one statistic that has always interested Fritz more than most. One stat that defines his coaching philosophy. One stat that explains how — and why — his Eagles racked up 613 rushing yards Saturday in their win against Georgia State.

"In over 22 years as a head coach, we've won over 91% of our games when we had one more yard rushing (than our opponent)," Fritz, 54, told USA TODAY Sports. "We set our offense up to be able to run the ball effectively, and our defense to stop people from running the ball."

To a tee, Georgia Southern accomplished both Saturday. Using their triple-option offense, the Eagles accumulated 613 rushing yards on 63 carries — led by Matt Breida's 201 yards and four touchdowns — while holding Georgia State to 47 rushing yards on 23 carries. Ten of Georgia Southern's 11 drives resulted in touchdowns, and the Eagles' team rushing yardage total broke the single-game Sun Belt Conference record.

"We hadn't seen (Georgia State) face any option teams, so we didn't know how much experience they'd had defending the option," Georgia Southern offensive coordinator Doug Ruse said. "The front there, the scheme they were running being a 3-4, we were confident we could get the ball out on the perimeter. We were hoping when we did that, we had an advantage in our team speed. We didn't know that going in, but as it turned out, I think we did."

Said quarterback Kevin Ellison, who ran for 115 yards and a score: "We're so diverse with our running backs, Matt Breida and L.A. Ramsby, all those guys do a great job running inside but having the speed on the outside to get the ball to the edge. That helps us out a lot. We focus on that, running the triple, being able to pitch the ball and run it on the perimeter."

Controlling the running game — both offensively and limiting it defensively — is so vital to Fritz's success, it's one of his five bedrock principles. It's also the main reason the marriage between the first-year coach and Georgia Southern has been so fruitful so far.

The Eagles are 6-2 overall and unbeaten in their first season in the Sun Belt after a lengthy reign as one of the Football Championship Subdivision's powers, one that included six FCS national championships from 1985 to 2000.

FBS is, undoubtedly, a step up.

"It's a little bit more and a little bit bigger, everything that you do at this level," Fritz said. That means opposing players are bigger, faster and stronger. Stadiums are more daunting. There also are more scholarships available, more talented players to recruit.

Though Georgia Southern had competed against FBS opponents in the past with some success — most recently beating Florida in 2013 — no one outside the program quite knew how successfully the Eagles could manage the transition in Year 1.

But those inside the program had an inkling, particularly after spring practices finished. Fritz recalled being impressed with the talent level already in the program — and that, of the six offensive linemen he'd rotate in the lineup, five would be seniors.

"When we got here in the spring, we saw the experience we had on the offensive line, and that's where it all starts," said Ruse, who came with Fritz from Sam Houston State. "Four of those five starters had played a lot of games here at Georgia Southern. Though the scheme has changed, there's no substitution for the experience they brought to the table. We knew we'd have good team speed.

"We were confident we'd be able to run because of the mentality these guys have had here."

The question became: How exactly to run the ball?

Fritz and Ruse began with the triple-option. Then they added some tweaks, based on Fritz's spread offense-based background.

"There's a lot of similarities with what they did last year, what they did in the past and what we do now," Fritz said.

"They were more of what people refer to as an under-center triple-option team. We're more of a shotgun, pistol-type option team. The biggest difference wasn't for the quarterbacks, running backs or receivers — it was for the offensive line. We're more of a zone blocking team with our offensive line. They were more of a fire-off-the-line kind of offensive line. Those guys had the biggest adjustment, that's been the real secret for us. Well, it's not a secret — we've got a really good offensive line.

"They'd done some of those things, but not every single down like we do. Also, with play-action passes a little bit more than they've thrown it in the past around here, they've done a good job of pass protection."

That helps, too, when Fritz wants to pass. Those instances aren't all that common, but they're a bit more frequent than last season. Through eight games, the Eagles have attempted 101 passes. They attempted 102 passes all of 2013.)

"Forever around here at Georgia Southern — with the exception, I guess, of one or two years, they've just been a true man-blocking triple-option scheme," Ruse said. "We've had to transition to a zone, which is probably about 70% of what we do in the running game, all off the inside zone. It all looks different, but that's the base scheme up front for the O-line. That was the biggest hurdle — we had to teach different footwork, a little bit slower tempo and mentality coming off the ball. …

"We're still running the option, which Georgia Southern has done around here for a very long time and has done extremely well. We're just doing it from a zone scheme with a quarterback in the gun. That's the biggest difference."

It's worked quite well, in part because it's allowed the Eagles to give defenses a variety of looks. It's also paved the way for some explosive plays. Georgia Southern has 102 rushes of 10 yards or more, which is the most in FBS and 18 more than the next-best team, Georgia Tech. The Eagles' offense is also running just 1.49 plays per point scored this season, per SportSource Analytics, another mark that is better than any other FBS team.

Georgia Southern is averaging 402.1 rushing yards per game — again, best in the nation. If the Eagles keep this up, they could become just the fourth team in FBS history to average more than 400 rushing yards per game.

"We're obviously proud of being the No. 1 rushing team in the country," Fritz said. "But we're going to call our games in order to win, and do what we need to do to win instead of going for any type of record."