The Ohio State Buckeyes have been atop the Big Ten power rankings most of the season. They'll stay there for a very long time.

Ohio State's win against Michigan secured a 12-0 season, just the sixth undefeated, untied campaign in team history. While the Buckeyes won't be in Indianapolis this week for the league championship game, they have proved to be the class of the conference after beating every top team in the league except Northwestern.

Nebraska retains the No. 2 spot, and most of the rankings remain the same after Week 13. Our toughest decision came at No. 3, between Michigan and Penn State. If only the teams had played each other this season.

To the rundown ...

1. Ohio State (12-0, 8-0 Big Ten, last week: 1): Sure, the Big Ten is down and Ohio State has its flaws, but any team that runs the table in any season deserves a ton of credit. Urban Meyer took a seven-loss team with significant depth issues and ran the table in his first year. Braxton Miller and the offense carried the Buckeyes early this season, but the defense stepped in the second half of Big Ten play. Ryan Shazier, Johnathan Hankins and others blanked Michigan in the second half to win The Game and ensure perfection.

2. Nebraska (10-2, 7-1, last week: 2): Most of us thought Bo Pelini was crazy when he talked about winning out moments after his team had been beaten 63-38 at Ohio State. Bo might have thought so, too. But his players believed and found a way to claim the Legends Division title and a spot in Indianapolis. Nebraska needed its defense in a big way at Iowa and received huge performances from defensive end Eric Martin and others. And with Rex Burkhead back in the fold at running back, the Huskers will be even better the rest of the way.

3. Michigan (8-4, 6-2, last week: 3): We gave Michigan a slight edge against Penn State because the Wolverines had no bad losses and gave Ohio State a tougher test. The Wolverines' defense did a nice job keeping Ohio State out of the end zone Saturday, but the offense disappeared in the second half, recording just 60 total yards and four first downs. Offensive coordinator Al Borges got predictable and must iron out the game plan before a tough bowl matchup against an SEC opponent.

4. Penn State (8-4, 6-2, last week: 4): Bill O'Brien described his team as resilient all season, and Penn State once again showed why in Saturday's overtime win against Wisconsin. Playing without star linebacker Michael Mauti, the Lions' defense shut down Wisconsin for most of the game, receiving a huge performance from defensive tackle Jordan Hill. Zach Zwinak stepped up at running back and kicker Sam Ficken, who took so much abuse earlier in the season, went 3-for-3 on field goal attempts and hit the game winner in overtime. What a satisfying way to end the season for O'Brien and his crew.

5. Northwestern (9-3, 5-3, last week: 5): If you're searching for good stories amid the Big Ten morass this season, look no further than Pat Fitzgerald's Wildcats. A young team exceeded all expectations during the regular season and was a play or two away from going to the Big Ten title game. Northwestern steamrolled Illinois with its dynamic rushing attack led by quarterback Kain Colter and running back Venric Mark. Fitzgerald tied Lynn Waldorf for the school's all-time coaching wins list with his 49th. An opportunistic defense stepped up, too, as Northwestern secured a spot in a Florida bowl (most likely Outback).

6. Wisconsin (7-5, 4-4, last week: 6): Another close loss for the Badgers, who had an offensive spark early and late but disappeared in between. Wisconsin's defense has made strides during the Big Ten season, but the offense simply lacks consistency, especially up front. It has proved costly in three overtime defeats this year. The Badgers are the third-best team in the Leaders Division but will go to the Big Ten title game, where they'll try to finish a bit better against Nebraska. Quarterback Curt Phillips has shown poise late in games.

7. Michigan State (6-6, 3-5, last week: 7): The Spartans went to their bread and butter -- defense and Le'Veon Bell -- to get past Minnesota and reach the six-win plateau. Michigan State's defense was simply dominant at TCF Bank Stadium, holding the Gophers to four net rush yards and three points on offense. Bell racked up a career-high 266 rush yards and a touchdown, his third 200-yard effort of the season. Michigan State didn't have the season it envisioned, but at least it has a chance to get better during bowl practices before a potential springboard for 2013.

8. Purdue (6-6, 3-5, last week: 9): Like Michigan State, Purdue underachieved this season but found a way to squeak into a bowl game. Credit quarterback Robert Marve, running back Akeem Shavers and the rest of Purdue's seniors for refusing to let the season go down the drain after an 0-5 start to Big Ten play. Shavers and Marve were brilliant against Indiana, and Frankie Williams and the Purdue secondary stepped up as well. It wasn't enough to save coach Danny Hope, but Purdue can win its second straight bowl and end a turbulent season on a good note.

9. Minnesota (6-6, 2-6, last week: 8): Big Ten play was no picnic for the Gophers, who endured numerous injuries, quarterback changes, the A.J. Barker turmoil this week and back-to-back losses to finish the regular season. Minnesota should get healthier before its bowl game, but it has a long way to go on the offensive side after rushing for four net yards Saturday against Michigan State. The next few weeks are big for freshman quarterback Philip Nelson, who struggled in his last two games.

10. Indiana (4-8, 2-6, last week: 10): The past three weeks showed that Indiana still has a long way to go to legitimize itself in the Big Ten. A defense that has struggled for more than a decade surrendered 163 points in losses to Wisconsin, Penn State and Purdue. After taking great care of the ball, quarterback Cameron Coffman had seven interceptions in his final three contests. Indiana made progress in Kevin Wilson's second season, and a big opportunity awaits in 2013 with eight home games. But there's a lot of work ahead in the offseason.

11. Iowa (4-8, 2-6, last week: 11): The defense came to play on Black Friday, but an offense that had sputtered all season went out with a whimper. Iowa failed to convert two more turnovers into points, and coordinator Greg Davis once again left Hawkeye fans pulling out their hair with his perplexing play calls. What looked like an eight- or nine-win season in September turned into a complete mess for Kirk Ferentz's crew. The Legends Division will be loaded again in 2013, so Iowa faces a critical offseason.

12. Illinois (2-10, 0-8, last week: 12): There are really bad teams, and then there's Illinois. Tim Beckman's first season mercifully ended Saturday, but not before another embarrassing road loss, this time at the hands of a rival. The Illini's offense actually showed up early, but eight first-half penalties, four turnovers and a defensive front seven that had no answer for Northwestern's run game ensured the Orange and Blue would end the Big Ten season winless for the fourth time since 1997. Beckman, who earned a penalty by accidentally contacting an official during a Northwestern interception, has a lot to fix.