A lot of talking heads are going to spew a lot of words about Iowa's defense for the next week, but how good are they really?
I guess the first question we need to ask ourselves is: Have they played anybody?
That's tough half way through the year. It's beginning to look like a lot of the B1G is fraudulent this year, so it may be that a lot of our upcoming opponents aren't what they seem. If we assume this to be true, the only way to analyze how you do against a bad schedule is seeing how much better you do against it than everyone else does. This is usually the purview of DSA, but I have a lot going on this week so...
So before we get into a poor-man's DSA, let's see if maybe that's what's called for. Let's look at Iowa's defensive rankings compared to the average offensive rankings for its FBS opponents in the same categories. For comparison, I've included the same numbers for Illinois, the best defense by raw statistical measures.
The first thing to note is that both of them have played an amalgamation of crap. Most teams have at this point in the year, but... I mean... Woof
The only category for either team where the opponents struggle all the way up to Mt. Mediocrity is Rushing yards per game, and that pulls the Iowa defense all the way down into the 20s. Still good, but nowhere near the single digit level that they and Illinois enjoy against the rest of that garbage.
Having said that: I've seen them play. Iowa looks solid. Illinois looks very good against the pass. No one is saying they suck. The point is that there is good reason to believe that they are not the juggernauts that context-free statistics might tell you they are.
So to really determine if either of these defenses is good, let's see how well they do against their opponents compared to how everyone else does against their opponents. Instead of full-on DSA though, let's just rank every team that played each of these team's opponents by the 7 metrics in the table above. Then we can see what the Hawkeyes' and Illini's average rank is.
For example, the most impressive category for any of them, is scoring defense for Iowa. While Illinois is first in the nation in this metric, it is Iowa that has held all but one of it's FBS opponents to their fewest points of the year; and that exception (Iowa State) was held to its second fewest points of the year. So Iowa's rank is 1 for four of the teams that it has played, and its rank is 2 for Iowa State. This makes its average rank for scoring defense 1.2 among its opponents. Illinois ranks 1 for four of its opponents as well, but ranks 2nd against Minnesota (Purdue held the Gophers to fewer points) and 3rd against Indiana. So Illinois' rank comes out to 1.5.
Doing this for all 7 categories we get the following:
Iowa is top-ranked among the performances against its opponents in 19 of 35 possible categories (5 FBS opponents times 7 categories = 35).
Illinois is top-ranked among the performances against its opponents in 19 of 42 possible categories (they had 6 opponents).
Based on this analysis then, both are really good, but not elite. If we compare these numbers to the standard by which all dominance should be judged (the Ohio State offense)...
The Ohio State offense gave the top-ranked performance in the 7 above categories 27 out of a possible 42 times, and 26 of a possible 35 times since the aberration that was the ND game.
Based on DSA of past years, being top-ranked in one of the above stats for about 1/3 of them is very good. Pushing above 1/2 like Iowa's defense is exceptional. Moving above 70% like Ohio State's offense has been for the past 5 weeks is unheard of. (The 2006 Buckeyes had a top performance in these categories right around 1/2 of the time.)
KEY POINT:
Ohio State's defense doesn't fair too bad by this analysis: The Silver Bullets are top ranked in 17 of 42 categories, just 2 behind Illinois who everyone thinks is the best in the country. And the Buckeyes are improving. They held the Spartans to their lowest number of the year in 5 of the 7 categories.
Even more interesting, if you take an average of all categories across all opponents, the rankings come out as follows (lower numbers are better).
Illinois Defense: 2.333
Iowa Defense: 2.086
Ohio State Defense: 2.071
Ohio State Offense: 1.548
That's right: The Ohio State defense has had a higher-ranked average performance vs the other teams their opponents have played than Iowa and Illinois. Not only that, but both Iowa and Illinois had the WORST performance in at least one category for one opponent, whereas for Ohio State this has not happened even once on offense or defense.
Conclusion: Illinois' defense is good. Watch them play; they're good. But based on this analysis, Iowa appears to be better. They are legitimately a very good defense, and they are more consistent than the Illini. Odd as it sounds though, the Silver Bullets are not at all far behind, and at the rate they're improving they stand a good chance of being better by the end of the year. The sad part for Iowa is that the Silver Bullets are facing Petras and company on Saturday, whereas the Hawkeyes are going to have their stats ruined by Stroud. More on how this is a bad matchup for Iowa (or bloody well OUGHT to be) as the week unfolds.