While every college football team would prefer to have an established, superstar No. 1 running back, using a committee of options is the preferred approach to save wear and tear on the starter. Some teams prefer to split the carry workload close to a 50-50 split or use certain players in situational roles. Regardless of the usage, more teams are looking to a committee of players to establish a rushing attack. And with that in mind, it's not easy to rank the best backfields in college football. Weighing a team with a clear superstar but little depth, as opposed to a team with three proven options and no standout No. 1 option is a tough assignment.

Related: College Football's Top 50 Players for 2015

How did we come up with these rankings? A couple of factors were considered. Depth, overall talent, production, level of competition and projected output in 2015 all factored into the rankings for the backfield. While some teams may have experienced a down year last season, having a different quarterback or a change of scheme can make a huge difference. These rankings reflect projection for 2015, not solely what teams have accomplished in 2014.

College Football's Top 35 Running Back Units for 2015

1. Georgia

The Bulldogs got an early preview of their 2015 backfield after Todd Gurley’s 2014 season ended following a suspension and torn ACL. Nick Chubb rushed for only 224 yards through the first five games but emerged as one of the SEC’s top running backs in the second half of last year. The five-star recruit from Georgia finished 2014 with 1,547 yards and 14 rushing scores. Chubb averaged at least 8.0 yards per carry in three of his last five games. Sony Michel also impressed as a true freshman last year, averaging 6.4 yards per carry. Michel and Keith Marshall will compete for the No. 2 spot behind Chubb.

Related: College Football's Top 30 Linebacker Units for 2015

2. Oklahoma

A freshman was supposed to make an impact at running back for Oklahoma last season, but most believed it would be Joe Mixon. However, Mixon was suspended for the entire year, allowing Samaje Perine to emerge as the Big 12’s top running back. Perine set the single-game rushing record with 427 yards against Kansas, led all freshman running backs with 1,713 yards and added 21 scores. Mixon is slated to return in 2015, giving Oklahoma a dynamic one-two combination at running back. Alex Ross is another weapon for new offensive coordinator Lincoln Riley after averaging 6.8 yards per carry in 2014.

3. Ohio State

With an offensive line that was struggling to find its footing early in the year, Ezekiel Elliott got off to a slow start in 2014. However, no running back was performing at a higher level by the end of last season. Elliott finished with three consecutive 200-yard efforts, including 246 yards and four scores in the national championship game against Oregon. Elliott is one of the favorites to win the Heisman, but he won’t have to shoulder all of the workload. Curtis Samuel is ready for a bigger role after averaging 6.6 yards per carry last year. True freshman Mike Weber may end up as Elliott's top backup at running back by the end of 2015.

Related: College Football's Top 35 Defensive Lines for 2015

4. Alabama

T.J. Yeldon left Tuscaloosa for the NFL, but there’s no shortage of talent at running back in Tuscaloosa. Junior Derrick Henry – one of college football’s most physically impressive running backs – is set to take the lead role in the backfield after recording 990 yards and 11 scores last season. Kenyan Drake is back from a serious leg injury to assume the No. 2 role. He will also see his share of receptions as a weapon on passing downs. Bo Scarbrough’s status is uncertain for the 2015 season after suffering a torn ACL in spring practice. Talented true freshman Damien Harris could be the No. 3 back for coordinator Lane Kiffin.

5. Florida State

With Jameis Winston off to the NFL, the rushing attack should be a bigger part of Florida State’s offense in 2015. Dalvin Cook was one of the top running back recruits in the 2014 signing class and averaged 141.3 rushing yards per game over the final three contests of 2014. After accumulating only 170 carries last season, Cook is poised for an uptick in touches and an opportunity to push for All-America honors in 2015. Mario Pender (206 yards last year) is also due for a bigger workload, while true freshman Jacques Patrick will also factor into the mix.

6. LSU

With uncertainty surrounding LSU’s passing attack once again, it’s Leonard Fournette’s show on offense. The sophomore is arguably the most talented running back in college football and should be one of the preseason favorites to win the Heisman Trophy in 2015. In 13 games as a true freshman last year, Fournette rushed for 1,034 yards and 10 scores. While Fournette is locked into the starting job, the backup situation is unsettled. Sophomore Darrel Williams is the frontrunner, but freshmen Derrius Guice and Nick Brossette are expected to see carries.

Related: College Football's Top 30 Defensive Backfields for 2015

7. Pittsburgh

There’s a new coaching staff, but the gameplan for the Panthers won't change on offense. Running back James Conner is one of the best in the nation and is the reigning ACC Player of the Year. In 13 games last season, Conner recorded 1,765 yards and 26 scores. Rachid Ibrahim was lost with an Achilles injury, leaving Chris James (437 yards) and true freshman Darrin Hall as the top backup options.

Related: College Football's Top 30 Offensive Lines for 2015

8. Arkansas

Behind a massive offensive line and two of the SEC’s top running backs, the Razorbacks have averaged 200 rushing yards per game in back-to-back seasons. Alex Collins and Jonathan Williams finished 2014 as the only running back duo in college football to both reach the 1,000-yard mark. However, the backfield suffered a huge loss when Williams was lost for the season due to a foot injury suffered in fall practice. Collins will step into the No. 1 role after recording 1,100 yards and 12 touchdowns last season. True freshman Rawleigh Williams III and fullback Kody Walker provide depth and will help to fill the void left by Jonathan Williams.

9. Oregon

The Ducks have produced a 1,000-yard rusher in eight consecutive seasons, and that streak should extend to nine in 2015. Royce Freeman led the team with 1,365 yards and 18 scores as a true freshman in 2014. Freeman is Oregon’s go-to back, but the No. 2 spot is up for grabs after Thomas Tyner was ruled out for the year due to shoulder surgery. Touted freshmen Taj Griffin and Tony Brooks-James will be needed to fill Tyner’s shoes in 2015.

10. Baylor

While most of the attention on Baylor’s offense usually focuses on the quarterbacks and receivers, the Bears have averaged at least 200 rushing yards a game in four consecutive seasons. This year’s stable of running backs might be the most underrated group nationally. Shock Linwood returns after leading the team with 1,252 yards and 16 scores last season. Johnny Jefferson (5.2 ypc in 2014), Devin Chafin (383 yards) and redshirt freshman Terence Williams will compete for carries behind Linwood.

Related: College Football’s Top 35 Receiving Groups for 2015

11. UCLA

12. Tennessee

13. Auburn

14. Wisconsin

15. Miami (Fla.)

16. Michigan State

17. Utah

18. Arizona

19. California

20. West Virginia

21. TCU

22. USC

23. Boston College

24. Toledo

25. Marshall

26. WKU

27. Rutgers

28. San Diego State

29. Georgia Southern

30. Appalachian State

31. Michigan

32. NC State

33. Northwestern

34. Texas Tech

35. North Carolina