Although Iowa owns the all-time series record 46-23-3, Northwestern has won five of its last six against the Hawkeyes, including three straight starting in 2008.
It's one of the great mysteries of Big Ten football, just like Iowa's record of 8-2 against Penn State in the last 10 meetings.
But there are reasons for everything, and we'll look inside the numbers to see just how such a streak could have happened.
But first, let's take a look at some of the most intriguing numbers:
• Iowa is 20-4 at Kinnick Stadium since the beginning of 2008. It's 0-2 against Northwestern and 20-2 against everyone else in that span (the other two losses came to Ohio State and Wisconsin in 2010)
• If Northwestern wins Saturday, it will go more than ten years since losing in Iowa City, with the last loss coming in 2002
• In each of the past six meetings, Northwestern has been the underdog five times and the favorite once. It won all five games as the underdog and lost as the favorite (The Wildcats are the underdog this year) • Former Iowa quarterback Ricky Stanzi was 26-9 as a starter at Iowa. He was 3-0 against Penn State and 2-0 against Michigan, but 0-3 against Northwestern
Iowa isn't a national power by any means, but it's a very good program and has been especially good this decade. For any team—much less Northwestern—to put up numbers like that is unprecedented.
However, Northwestern's wins weren't flukes. Let's take a closer look at each of the past three years to see how the Wildcats were able to win.
2008 This was a combination of great timing Northwestern and the fact that the Wildcats had a pretty darn good team.
Iowa was still struggling to find its identity, having switched between two quarterbacks—Ricky Stanzi and Jake Christensen—through the non-conference season.
Iowa had a young team that year and Northwestern was experienced. At that point the Hawkeyes still had trouble winning close games and Northwestern came through in the clutch.
Iowa improved later in the year—it beat No. 3 Penn State in November and finished with a win in the Outback Bowl—so who knows how that game would have gone later in the year.
However, that Northwestern team, which finished 9-3, was one of the best teams of the Pat Fitzgerald and the win was hardly the upset that the points spread portrayed it to be.
2009 In all honesty, Northwestern probably should have lost this game.
The Wildcats had a solid squad, but Iowa was undefeated and ranked No. 4 in the country.
It sure looked like it would be a blowout in the early-going, as the Hawkeyes went up 10-0 in a hot start, but quarterback Ricky Stanzi was sacked in the endzone by Corey Wootton and went out for the remainder of the regular season.
Stanzi fumbled on that play and the Wildcats recovered it for a touchdown.
Iowa's offense sputtered down the stretch and the defense couldn't hold, as Northwestern came away with a big 17-10 win that catapulted it to the Outback Bowl.
That was a good Northwestern team, and while it probably couldn't have beaten a full-strength Iowa squad, it came through in the clutch to win.
2010 The 2010 version of Iowa-Northwestern was the Dan Persa show.
He did everything for the Wildcats, helping them climb back from a 17-7 fourth quarter deficit to win 21-17.
It was a bittersweet moment for NU; it was the biggest win of the season—Iowa came in No. 13 in the country—but Persa ruptured his Achilles on a touchdown pass in the Wildcats' final offensive play, forcing him to sit out for the final three games of 2010 and the first three games of 2011.
Northwestern out-willed Iowa for the win and criticism of Kirk Ferentz's conservatism, as opposed to Pat Fitzgerald's energy, returned.
With Persa, that was a scarily underrated team, and if he had been able to play for the final three games of the season, Northwestern may have finally come away with a bowl win.
Those games weren't flukes, Northwestern just played better or came away with better breaks (re: Stanzi's injury). The Wildcats didn't win "because they own Iowa"; they won because they had better teams or were better on that day.
If this Northwestern team wins in Iowa City, it won't be because it "has Iowa's number."
This defense is much worse than any of the defenses the past three years, but Iowa's defense is worse than it was in any of those, either.
The Iowa passing game, led by quarterback James Vandenberg and star wide receiver Marvin McNutt, will get its yards against the week Northwestern secondary, so this game will be on Dan Persa and the offense.
If Persa can continue his hot start—he must get better on the run, though—the Wildcats can win. However, this should be a close game, and like it has against Iowa in the past, Northwestern must be able to pull through in the clutch.
NU hasn't been able to do that so far this season, but as it has been the past three years, the Iowa game could be a launching pad for success going forward this season.