Posted by ESPN.com's Adam Rittenberg
The Big Ten had more image-shaping games in Week 3, but Saturday revealed plenty about the league. Entering the season, quarterback play looked to be a strength of the Big Ten, while several teams looked weak on the defensive side. But four games into the fall, teams like Michigan State, Northwestern, Minnesota and Purdue have shown obvious improvement on defense. Meanwhile, several of the league's veteran quarterbacks -- Todd Boeckman, C.J. Bacher, Brian Hoyer, Jake Christensen -- have had some struggles.
There was plenty of history in Week 4. Joe Tiller became Purdue's all-time winningest coach. Terrelle Pryor had the best debut for a freshman quarterback in Ohio State history. And Northwestern finally swept its non-league schedule to start 4-0 for the first time since 1962.
Here are five revelations from the week:
1. Upgrades on defense -- For all the talk of the spread offense sweeping through the Big Ten, this is turning into a defensive league. Michigan State nearly shut out an opponent for the second consecutive game as a hard-hitting defense continues to reflect head coach Mark Dantonio. Minnesota, the nation's worst defense last season, held Florida Atlantic to three points and increased its takeaways total to 13, which ties for third in the nation. Northwestern bailed out its sputtering offense with one of the best defensive efforts in years -- a school-record four rush yards allowed, four takeaways and two blocked field-goal attempts against Ohio. Penn State kept Temple out of the end zone for the second straight year, and Purdue's secondary continued to make big plays.
2. Ringer on the Heisman radar -- Michigan State senior running back Javon Ringer didn't get much preseason hype for the Heisman Trophy, so it's taken awhile for the country to recognize how good he is. Fortunately, Ringer provided more evidence against Notre Dame, rushing for 201 yards on 39 carries to become the first Michigan State player ever to rush for 200 yards or more in consecutive games. Few players in the country are more valuable to their teams than Ringer, whose workload is unmatched. He ranks second nationally in rushing average despite 30 more carries than any other FBS back.
3. Pryor ready for the spotlight -- Maybe none of us should be surprised that Pryor has become Ohio State's starting quarterback four games into his career. The heralded freshman threw a record four touchdown passes in leading the beleaguered Buckeyes past Troy on Saturday. He's far from a finished product and faces much tougher tests down the line -- an Oct. 4 trip to Wisconsin comes to mind -- but Pryor has shown a beyond-his-years presence, avoiding major mistakes and showcasing his obvious physical skills. He has earned Jim Tressel's trust as a true freshman, which isn't easy to do.
4. Penn State fools us with "sloppy" blowout -- Quick, name a team that has been more impressive in the first four games than Penn State. The Lions have outscored their opponents 211-40 and rank in the top 10 nationally in nine major statistical categories on both sides of the ball. Their latest display of domination came against Temple, but players and coaches called the 45-3 win "sloppy." Penn State started slow but still put up 31 points in the first half, allowing ailing coach Joe Paterno to spend the second half in the press box. If Penn State keeps this up, Paterno could coach from his couch.
5. Minnesota is league's biggest surprise -- Few expected another 1-win season in the Twin Cities, but a 4-0 start for Minnesota? It seemed unlikely at best. But the Gophers have repaired a disastrous defense with junior-college transfers and the emergence of several holdovers (Kyle Theret, Marcus Sherels, Willie VanDeSteeg). A new-look secondary continues to come up with big plays, as Minnesota has eight interceptions and 33 pass deflections this season. The offense continues to roll behind quarterback Adam Weber and wideout Eric Decker, and Minnesota heads into league play with plenty of momentum.