Big Ten power rankings

Posted by ESPN.com's Adam Rittenberg

Penn State has been the league's most impressive team all season. Now it's safe to say the Nittany Lions are also the Big Ten's best squad. As you'll see below, Wisconsin's second-half meltdown at Michigan had consequences, and there's a bit of shuffling in the bottom half after some surprising performances (Michigan) and some disappointing ones (Purdue).

Unlike other BCS conferences, the Big Ten doesn't appear to have any terrible teams, so expect plenty of movement the rest of the season.

1. Penn State -- The Nittany Lions got some good news Thursday when Oregon State, a team they crushed Sept. 6, upset top-ranked USC. Things got better Saturday night after Penn State introduced itself to adversity for the first time this season and overcame it thanks to explosive play by Derrick Williams, Evan Royster and Daryll Clark. So far H and D have been the call letters in State College. They could soon be replaced by B, C and S.

2. Ohio State -- America's most over-publicized big toe has healed, and maybe so has Ohio State after a rocky start. An offensive backfield of freshman quarterback Terrelle Pryor and a healthy Chris "Beanie" Wells got off to a strong start against Minnesota. Wells clearly provides an emotional boost for the offense, which was admittedly lackluster during non-league play. A road win against Wisconsin could spur Ohio State for a league title run.

3. Wisconsin -- The power run game went powerless, a physical defense lost its edge and the Badgers saw a 19-point halftime lead evaporate at Michigan Stadium. With both Penn State and Ohio State coming to Madison, Wisconsin looked to be in the driver's seat for the Big Ten title, but it began a rough stretch on a sour note. The good news is the Badgers can vault back on top the rankings by holding serve at Camp Randall Stadium, where they have never lost under coach Bret Bielema.

4. Michigan State -- The Spartans survived a wild game at Indiana and won their fourth straight. Coach Mark Dantonio certainly can't be happy with his defense giving up 473 yards, but Michigan State got a much-needed boost from senior quarterback Brian Hoyer, who threw two touchdowns and established an option besides Javon Ringer. Wins against slumping Iowa and undefeated Northwestern would put the Spartans in the league title discussion when Ohio State visits Spartan Stadium on Oct. 18.

5. Northwestern -- Respect is hard to come by for Northwestern, but the program's first 5-0 start since 1962 will gain notice around the league. Opportunistic play lifted the Wildcats past Iowa, and a slumping offense gained confidence behind quarterback C.J. Bacher in the second half. With home games against Michigan State and Purdue followed by trips to Indiana and Minnesota, Northwestern could continue to sneak up on the league.

6. Illinois -- Both Illini losses have come against top 10 teams (Missouri and Penn State), and wideout Rejus Benn did all he could to keep the team close against the Lions on Saturday night. But the defense just isn't the same without All-American J Leman in the middle, and a veteran line pegged to be the team's strength has underperformed. Illinois has some work to do to get back in the first tier.

7. Michigan -- I was ready to put Michigan at the bottom of the rankings after watching its first-half performance against Wisconsin. But quarterback Steven Threet never lost confidence and ignited the offense late in the third quarter. The Wolverines' offense limited mistakes and began utilizing all of its weapons in mounting the biggest comeback in Michigan Stadium history. But the real reason the Wolverines aren't several spots lower is a defense that shines in pressure situations.

8. Iowa -- The Hawkeyes identified their quarterback in sophomore Ricky Stanzi, but a five-turnover disaster against Northwestern left them with another loss. Saturday's trip to Michigan State is a must-win for Iowa and head coach Kirk Ferentz, who can't afford problems on the field after so many off-field issues. This is a good team with a solid defense and a dynamic running back (Shonn Greene), but it needs to start playing to its potential.

9. Minnesota -- It's still hard to get a good read on Minnesota. The Gophers are definitely better on defense, but they struggled to contain Wells and Pryor. Turnovers were a problem for the first time this season, as they were throughout 2007. Minnesota must show better discipline this week in a crucial home matchup against Indiana. The Gophers are ahead of the Hoosiers for now, but they need a win to stay that way.

10. Purdue -- The Boilers' defense really misses Jason Werner, but they had held things together until a disastrous third quarter against Notre Dame. Quarterback Curtis Painter always will put up big numbers, but the offense struggled in the red zone and lacks its usual weapons. Things don't get any easier for Purdue, which hosts high-powered Penn State this week before visiting Ohio State.

11. Indiana -- The Hoosiers did some good things against a superior opponent (Michigan State), but their defense simply isn't consistent enough. A 2-2 start with four home games to begin the season isn't what head coach Bill Lynch had in mind. The Hoosiers now travel to Minnesota for a crucial game that could make break their hopes for another bowl run.