Some trends in the Big Ten seem to defy explanation, and Iowa finds itself on opposite sides of two of them.
The Hawkeyes have won eight of their last nine meetings against Penn State, including each of the past three contests. Iowa derailed Penn State's national title hopes in 2008, reshuffled the Big Ten race with a win in Happy Valley last fall and held Penn State without a touchdown in a dominating win Oct. 2.
Joe Paterno has lost more games to Iowa (11) than any other team in his head-coaching career except for Ohio State (13).
But it has been a very different story for Iowa against Northwestern. The Wildcats have won four of the teams' past five meetings, including three at Kinnick Stadium, where Iowa is 49-10 since 2002. Northwestern ended Iowa's perfect season in 2009 with a 17-10 come-from-behind win at Kinnick. Kirk Ferentz is just 4-5 against Northwestern as Iowa's coach.
"I really couldn't tell you why we've had so much success against Penn State and not so much against Northwestern," Iowa senior guard Julian Vandervelde said this week. "I really do think it comes down to the little details, the mistakes, the fundamentals and the basics. Year in and year out, we're able to execute against Penn State and not so much against Northwestern."
Iowa needs a polished performance Saturday as it visits Northwestern. The 13th-ranked Hawkeyes remain very much in the Big Ten title race, but they can't afford to slip up, especially as next week's home showdown against No. 9 Ohio State looms.
By most accounts, Saturday's game is one Iowa should win. The Hawkeyes are more experienced on both sides of the ball. Iowa's biggest strengths (the play-action pass and a pressuring defensive line) match up well against two of Northwestern's weaknesses (the secondary and the offensive line). Iowa has more at stake and should have no trouble getting motivated after the struggles.
But the Hawkeyes know what should happen and what does happen are two different things, especially in this series.
Many have tried to explain Northwestern's recent success, even pointing to the Hayden Fry-Gary Barnett exchange after the 1994 Iowa beatdown of Northwestern as the start of a shift (Northwestern is 8-5 against Iowa since 1995).
Iowa has dealt with key injuries in the last two losses -- running back Shonn Greene in 2008 and quarterback Ricky Stanzi in 2009 -- but Northwestern also played most of last year's game without star quarterback Mike Kafka. Northwestern running back Adonis Smith was quoted this week as saying coach Pat Fitzgerald "hates Iowa," but does that matter on the field?
The real explanation, according to Ferentz, is pretty simple.
"They have done a good job of playing the way you're supposed to play and we haven't," he said. "I think we have had nine turnovers and they have had two in two years. ... On top of that, we screwed up on special teams, several times, a couple years ago. To me, that's been the story of it. You've got two even teams. One team played clean, played really well and the other team didn't and it's pretty academic who is going to win or lose."
Iowa has looked uncharacteristically sloppy against NU, but Vandervelde says there's no mental block against playing the Wildcats.
"People don't expect them, for some reason, to come out and swing as much as they do and hit as hard as they do," he said. "Sometimes it catches people by surprise, I think. They're smart guys, they're going to watch tape and figure out what you do, so you really can't make mistakes. You have to be ready for everything they're going to bring.
"Having played them for a couple of years now, I'm well versed in their style of play and I won't be surprised by anything, hopefully."