BOISE — For seven straight years - between Brock Forsey and Doug Martin - the Boise State football team didn't have a 1,000-yard rusher who weighed 200 pounds.
Martin broke that streak in 2010 and seems to have started a new trend for the Broncos: the return of the power back.
The Broncos enter this season with seven tailbacks who average 5-foot-10, 201 pounds. That's 11 pounds heavier than five years ago.
Among them are 220-pound, sophomore projected starter Jay Ajayi, 208-pound junior college transfer Derrick Thomas, 195-pound sophomore Jack Fields and 215-pound true freshman Aaron Baltazar.
The change wasn't planned, running backs coach Keith Bhonapha said, but coaches do appreciate the power style.
"The guys we've liked on film have been those guys - guys that are physical, guys that are downhill runners, that break tackles and have good speed," Bhonapha said. "It just so happens that they're bigger guys."
Martin, at about 210 pounds, topped 1,000 yards in 2010 and 2011. D.J. Harper, hit that milestone last year at 205.
Ajayi, who averaged 6.7 yards per carry with a physical style last year, is the favorite to join them this year.
"It's nice when they're big and good," coach Chris Petersen said. "They're harder to tackle - we know that for sure."
Tailback is one of the most intriguing positions on the team because of the youth. Ajayi, who rushed for 548 yards last year, and Fields, who rushed for 135, are the only tailbacks with major college football experience.
But the group includes some of the highest-profile recruits the Broncos have landed in recent years.
"I expect just to keep the ball rolling," Fields said. "Coach Bhonapha does a great job letting us know the standard we have at running back. We know Doug Martin, (Cedric) Minter, (Jeremy) Avery - all those guys that came through. So we know when we step on the Blue we have to bring our A-game."
Ajayi steps into the featured role - and a leadership position - in his third year in the program. He tore an anterior cruciate ligament in practice in 2011 and redshirted. He was impressive as the backup last year but expects to show more explosiveness this year after shedding 10 pounds and his knee brace.
"It's exciting, just to have that (starting) role," he said, "but at the same time, I'm just working every day to improve my game."
Thomas and Fields are competing for the backup job.
Thomas, who grew up in Texas, played high school football in Alabama and attended Butler Community College because he wasn't eligible for the NCAA, has worked "24/7", Bhonapha said, to make sure he doesn't waste any of his short time as a Bronco.
"Any time you get a junior college guy, they know their time is limited, and he knows that on that field is where he wants to be," Bhonapha said.
Thomas visited Ole Miss before his trip to Boise State, where he clicked with Bhonapha.
"When I first talked to Coach B, he put a lot in my ear that made me think about my future," Thomas said. "It just hit home. I came on a visit and just felt like it was the best place for me."
He arrived in January and impressed in spring ball. He carried that momentum into fall camp.
"I get more comfortable every day," Thomas said. "The more comfortable you are, the better you play."
That shows with Fields, too.
The Broncos needed him last year as a true freshman because of a lack of depth at tailback and on special teams. He's much more prepared to contribute now.
"He's gotten faster," Bhonapha said. "You can tell he has a little more savvy to him."
The Broncos likely will need at least one more tailback to contribute. That could be Baltazar - although coaches might redshirt him if the other three guys stay healthy.
"Aaron is a really smart kid," Bhonapha said. "He understands the offense for the most part. He's a true freshman, so he has those mistakes pop up every once in a while, but you talk about a guy who has great savvy out there on the football field. It's not too big for him so far at practice.
"I'm really excited to see what the future holds for him."
The same could be said for this group.
All of them have nearly their entire college football careers in front of them. Thomas is the only one scheduled to leave before the end of the 2015 season.
"We're all starving," Thomas said. "We're going to do whatever it takes to get where we want to be."
Chadd Cripe: 377-6398, Twitter: @IDS_BroncoBeat