Evaluating college football teams can be tricky when they have such a wide array of opponents. Even within one’s own conference, stats can be misleading.

Minnesota, for example, has the No. 4 scoring defense in Big Ten play, but it hasn’t faced any of the top six offenses. The Golden Gophers also have the No. 2 scoring offense in Big Ten play, but they haven’t faced any of the top five defenses. So their numbers look good, but given some context, they aren’t quite as impressive. And to be fair to Minnesota, that’s the case with a lot of statistics; you can twist them to fit your narrative, one way or the other.

So how do you really know who is good?

I read a stat about Iowa from The Athletic’s Scott Dochterman that was enlightening and seemed like a great way to judge defenses. Iowa has held six of its eight opponents to season lows in points. That’s not a perfect barometer for how good a defense is, but it’s telling because it means it’s not just doing pretty well against offenses that everyone else is also holding down.

Naturally, I was curious as to how that stacked up with the rest of the Big Ten (a league loaded with great defenses), and Iowa indeed led the conference in that stat. Ohio State (5) was second, followed by Wisconsin (4), Michigan (3), Penn State (3), Indiana (3), Michigan State (3) and Minnesota (2).

Then I looked at the top 10 scoring defenses in the country, and Iowa again held up well, tying with Utah and Clemson with six. Those three are followed by Ohio State (5), Wisconsin (4), Alabama (3), Penn State (3), Georgia (3), San Diego State (3) and Oregon (2).
Here’s another telling stat, via SportSource Analytics: Iowa is second in the country (behind only Ohio State) in relative scoring defense, which is the percentage of what a team gives up based on what the opponent normally scores.

The Hawkeyes (6-2) may be a bit underrated for a few reasons. For one, the Big Ten has so many good defenses. Ohio State, Penn State and Wisconsin have been in the top 10 nationally in most defensive statistics too, so Iowa typically gets lumped in with those other teams. It’s not like this is the Big 12, where a defensive performance of this magnitude would turn heads.
Another reason this group is a little overshadowed is that Iowa’s inept offense is so aggravating and is often a topic of conversation.

Remember when Iowa held Michigan in the Big House to 10 points and lost? The Hawkeyes are scoring on 96 percent of their red-zone trips, which is the best in the Big Ten; but they also settle for field goals 37 percent of the time, which is the most often in the Big Ten.
It’s not as if this Iowa defense is flashy. It is eighth in the Big Ten in interceptions with six and 10th in fumble recoveries with four – which puts them at 10th in forced turnovers with 10. And the Hawkeyes are just 11th in the Big Ten with 16 sacks (just 2.5 more than Chase Young has by himself).

But Iowa knows who it is and sticks to its script. The defense will almost always take priority over the offense, as Kirk Ferentz will consistently opts to pin an opponent deep in its own territory rather than take a risk in a fourth-and-short situation. Remember last Saturday against Northwestern? Iowa punted twice on fourth-and-1 in Northwestern territory in the second quarter. The Hawkeyes also had fourth-and-1 from Northwestern’s 10 in the fourth quarter and opted for a field goal. They play it safe, and that means their defense is almost never at risk.

While Ohio State and Penn State may be flashier and appear on SportsCenter more often, Iowa’s defense has been every bit as effective.