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The top 10 offensive backfields: Good QBs and good RBs mean you're in good shape

Fall practice is under way everywhere, and that means the 2012 season has started.

While we're still a bit more than three weeks from the first game, the final three weeks of waiting will seem like about two or three days compared to the past seven months.

Today, we unveil the first of our national unit rankings. We'll reveal one unit per day and end next Monday with coaching staffs.

The rankings take into account what the players have accomplished, how we think the players will do this season and sheer talent. But production does trump potential.

Here are the offensive backfield rankings. Next up: Receiving corps.

10. Kansas State

The key players: QB Collin Klein and TB John Hubert and Angelo Pease
The buzz: Klein isn't much of a passer, but he had a marvelous season on the ground last season. He rushed for 1,141 yards and set an NCAA single-season record for rushing TDs by a quarterback with 27. He scored at least one TD in 12 of K-State's 13 games and had multiple rushing scores in seven contests, including five against Texas A&M. Klein also threw for 1,918 yards and 13 scores. Hubert ran for 970 yards but just three touchdowns last season; he had three 100-yard games, including a 166-yard outing against Miami. Pease's 2011 season was ruined by injuries after he transferred in from junior college. He was a quarterback in high school in Cairo, Ga., playing for the sublimely named Cairo Syrupmakers.

9. Fresno State

The key players: QB Derek Carr and TB Robbie Rouse
The buzz: As everyone should know, Carr is the younger brother of former No. 1 NFL pick David Carr.

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Robbie Rouse has been a productive back for Fresno State and will be a three-year starter. (AP)

Derek was a first-time starter last season and threw for 3,544 yards and 26 TDs as a sophomore; he also completed 62.6 percent of his passes. Rouse, a senior, will be a three-year starter for the Bulldogs. He rushed for 1,549 yards and 13 TDs last season. In two games against Big Six foes (Nebraska and Ole Miss), Rouse ran for 292 yards and a TD. He has 3,157 career rushing yards, third-most among active players, behind only Montee Ball (3,310) and Denard Robinson (3,229).

8. Nebraska

The key players: QB Taylor Martinez and TB Rex Burkhead
The buzz: As with K-State's Klein, Martinez has a ways to go as a passer (though not as far as Klein) but is a dangerous runner. He rushed for 874 yards and nine TDs last season, giving him 1,839 yards and 21 TDs in his career. He has passed for 3,720 yards, with 23 TDs but also 15 picks. Martinez has a nice arm, but isn't all that accurate (career completion rate of 57.4). Burkhead seemed to like the move to the Big Ten last season; he rambled for 1,357 yards and 15 TDs. He's also a solid receiver.

7. LSU

The key players: QB Zach Mettenberger and TBs Spencer Ware, Michael Ford and Kenny Hilliard
The buzz: Mettenberger is far from a sure thing. He definitely has the physical tools, but he also is the guy who enrolled early out of junior college in 2011 so he could go through spring practice but never could beat out Jordan Jefferson or Jarrett Lee. But LSU's tailbacks are a sure thing. No team in the nation is deeper at the position. The Tigers return four backs who rushed for at least 336 yards and seven touchdowns and have three who ran for at least 539 yards and seven scores.

6. TCU

The key players: QB Casey Pachall and TBs Waymon James and Matthew Tucker
The buzz: Pachall exceeded expectations last season, his first as the starter. He threw for 2,921 yards

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Casey Pachall set some important school records as a first-time starter last season. (Idaho Press-Tribune)

and 25 TDs, including five (which tied a school single-game record) in a victory over Boise State. He also ran for four touchdowns. Pachall set school single-season records for completions (228), completion percentage (66.5) and passing yards. TCU would've been ranked higher on this list if not for TB Ed Wesley deciding to leave school for the NFL (he wasn't taken in the supplemental draft). James was TCU's leading rusher last season (875 yards), while Tucker led the Horned Frogs in rushing TDs (12). Together, that duo rushed for 1,577 yards and 18 scores.

5. Alabama

The key players: QB A.J. McCarron and TB Eddie Lacy
The buzz: McCarron is not overly gifted physically, but he does have a nice arm, a great understanding of the game and – oh, yeah – a national title ring. He threw for 2,634 yards, 16 touchdowns and five interceptions last season; he also completed 66.8 percent of his passes. Lacy looks as if he will be the latest Tide tailback to go from key reserve to focal point of the offense, joining Mark Ingram and Trent Richardson. Lacy ran for 674 yards and seven TDs last season. Richardson went from 700 yards and six TDs in 2010 to 1,679 yards and 21 TDs in '11. And Ingram went from 728 yards and 12 TDs in 2008 to 1,658 yards and 17 TDs in '09. We're not saying Lacy will make that type of jump, but if he doesn't rush for 1,200 yards, it will be a surprise. There's also excellent depth at tailback, which is normal for a Nick Saban-coached team.

4. Clemson

The key players: QB Tajh Boyd and TB Andre Ellington
The buzz: Boyd proved to be a great fit for coordinator Chad Morris' offense; Boyd threw for 3,828 yards and 33 TDs and also ran for five scores last season, Morris' first at the school and Boyd's first as the starter. Boyd had four 300-yard games and seven times threw at least three TD passes in a contest. In his four 300-yard games, he threw 14 TD passes and just two interceptions. He guided Clemson to the ACC title last season. Ellington should again put up good numbers, too. He ran for 1,178 yards and 11 TDs last season, and he had five 100-yard games, including a 212-yard outing against Maryland. He put up those numbers despite an ankle injury that caused him to miss one game and hampered him in a few others.

3. Michigan

The key players: QB Denard Robinson and TBs Fitzgerald Toussaint and Thomas Rawls
The buzz: Michigan fans get to enjoy Robinson for one more season. He ran for 1,176 yards (5.3 yards per carry) and 16 touchdowns, and also threw for 2,173 yards and 20 scores last season; remember that was in a pro-style offense, one that is not necessarily best-suited for his skill set. In his career, "Shoelace" has passed for 4,931 yards and 40 touchdowns and rushed for 3,229 yards and 35 more scores. He has a chance of becoming the NCAA's leading career rusher among quarterbacks; he is 1,252 yards away from breaking the record of 4,480 yards held by former West Virginia star Pat White. Toussaint ran for 1,041 yards and nine TDs and was especially strong down the stretch, rushing for 708 yards and five touchdowns in the final six games. But he has been indefinitely suspended after a DUI arrest and seems likely to miss a game or two. Sophomore Thomas Rawls, who had 13 carries last season, is Toussaint's backup. He is a physical runner with some speed.

2. Arkansas

The key players: QB Tyler Wilson and TBs Knile Davis and Dennis Johnson
The buzz: Wilson is a strong-armed guy who threw for 3,638 yards and 24 touchdowns last season, his

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Knile Davis (left) and Tyler Wilson give Arkansas two stars in the backfield. (AP)

first as the starter. He threw at least one TD pass in 12 of the Hogs' 13 games and had nine games with at least two TDs. He also had four contests with at least 300 yards. He should benefit from the return of Davis, who missed last season with an ankle injury. He rushed for 1,322 yards and 13 TDs in 2010 despite getting just 20 total carries in the first four games. He had six 100-yard games. Davis is a physical runner who also has breakaway speed. Johnson is a shifty guy with the speed to turn the corner and is a top-notch receiver.

1. USC

The key players: QB Matt Barkley and TBs Curtis McNeal and Silas Redd
The buzz: Barkley heads into the season as the frontrunner for the Heisman, and his decision to stay in school for his senior season made USC a top contender for the national title. Barkley, who will be a four-year starter for the Trojans, completed 69.1 percent of his passes and threw for 3,528 yards, 39 touchdowns and seven interceptions in 2011. He should graduate with school career records in completions, TDs, passing yards and total offense. Redd's transfer from Penn State gives the Trojans two returning 1,000-yard rushers. On a Nittany Lions team with shaky quarterback play and a mediocre passing attack, Redd ran for 1,241 yards and seven touchdowns last season; he had six 100-yard games. He would've been the focal point of Penn State's offense; he won't be the focal point of the Trojans' offense and seems unlikely to match his production from last season. But his presence gives USC coach Lane Kiffin another toy to play with offensively. McNeal ran for 1,005 yards and six TDs last season (he had just 24 carries in the first five games), and gives the Trojans an experienced and productive backup.

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