This list is based only on what players did in the 2012 season, and you had to be a full-time running back to make the list. (That means no Tavon Austin, 'Eers. Sorry.)
1. Joseph Randle, Oklahoma State: Randle carried the torch as the Big 12's biggest standout all season long at running back. He was mostly consistent and led the Big 12 in rushing by more than 300 yards, racking up 1,417 yards and 14 touchdowns on 274 carries. Strong season from an experienced player who's leaving early for the NFL.
Oklahoma State's Joseph Randle averaged 5.2 yards per carry this past season.
2. Lache Seastrunk, Baylor: Seastrunk wouldn't have even made this list heading into November, when he had just 181 rushing yards and was a non-factor in Baylor's offense. Then he sprinted ahead and near the top of this list by averaging more than 138 yards a game over the final six games of 2012. He ended the season as the Big 12's hottest player and helped Baylor finish the year 5-1 with the lone loss coming on the road against co-Big 12 champion Oklahoma. He says he's going to win the Heisman in 2013. We'll see.
3. James Sims, Kansas: Sims made a case for himself midseason as the Big 12's best back, racking up six consecutive 100-yard games and looking unstoppable, despite KU's passing game providing no balance for opposing defenses to respect. He's a physical runner who ascended near the top of this list despite missing the first three games of the season. He carried 218 times for 1,013 yards and led the Big 12 in rushing yards per game.
4. John Hubert, Kansas State: Hubert is criminally underrated because his partner in crime in the backfield, Collin Klein, attracts so much attention. He's got a low center of gravity at 5-foot-7 and 191 pounds, and is deceptively hard to bring down, despite his small stature. He's had nearly identical seasons the past two years, coming up just short of 1,000 yards in both seasons.
5. Damien Williams, Oklahoma: Williams broke out in a big way with a 65-yard touchdown run in the opener, and busted a 95-yard run against rival Texas. The juco transfer has a great balance of power and speed and provided a home-run threat that Oklahoma lacked after DeMarco Murray left. He finished with 946 yards and 11 scores on just 176 carries.
6. Tony Pierson, Kansas: Pierson proved himself early in the year when Sims sat, racking up a pair of 120-yard games. He's perhaps most valuable for KU in the passing game, though. His 760 yards came on just 116 carries, an average of 6.5 yards a touch. Only Seastrunk was higher among running backs with 75 carries. Pierson also caught 21 passes for 291 yards and two touchdowns, which is no small number in KU's offense. KU's leading receiver, Kale Pick, had zero touchdown catches and just five more receptions and 99 more yards than Pierson.
7. Glasco Martin, Baylor: Martin is the thunder to Seastrunk's lightning in the Bears' backfield. He's fantastic at getting tough yards when they're needed and provides a lot of power to Baylor's offense. His 15 touchdowns were tied for third in the Big 12, and he added 889 rushing yards on 179 carries.
8. Johnathan Gray, Texas: Gray's got as much potential as anyone on this list, and looked good when injuries forced him into full-time duty. The true freshman didn't quite look like a gamebreaker, but there's lots of time left in his career to prove himself. He became the second true freshman to lead Texas in rushing in two seasons, with 701 yards on 149 carries.
9. Kenny Williams, Texas Tech: Williams emerged as the best back in a crowded Red Raiders backfield. He runs against a lot of soft fronts because of Tech's wide-open offense, but Williams is tough to bring down and rumbled for 824 yards on 143 carries, scoring five times.
10. Andrew Buie, West Virginia: Buie will be remembered a long time for his legendary 207-yard performance in a win over Texas. He had just one other 100-yard game that season, but there's no denying his overall production. His 850 yards on 181 carries were eighth in the Big 12.