Disparity scores and the utter weirdness that is Northwestern football

In 2020, I had an idea. A dumb, only-brilliant-if-you’re-a-college-football-sicko idea, but an idea nonetheless.

When reviewing Bill Connelly’s SP+ rankings on ESPN (widely regarded as the best single number team metric in the public sphere of college football), it struck me just how disparate Northwestern’s two units were in their placement.

Heading into their opening contest vs. Maryland, the ‘Cats ranked sixth in the entire FBS in Defensive SP+, yet were still only slotted at 54th overall, as they were weighted down by an offense ranked 117th in the same metric.

The gap somewhat closed toward the season’s end, with NU rising to third and 93rd in Defensive and Offensive SP+, respectively, and there was no debate following the Citrus Bowl that Northwestern had proven themselves as one of the more formidable teams in all of college football in the pandemic-altered year.

However, it was also widely agreed upon that Northwestern did this largely in spite of their offense rather than because of it, and it’s this very dissonance that intrigues me year-after-year. Northwestern is good and save for a doomsday scenario type season (see: 2019) ensured a baseline level of competence under Pat Fitzgerald, yet they do so clearly due to one unit of the team, with the other half grading out as below average on a consistent basis. It should be impossible to finish as a Top 10 team in the AP Poll with what some would say is an offense that’s worse than 92 other teams in the same sport, yet here the ‘Cats are.

In that previously mentioned piece I wrote in the summer of 2020, I touched on my “disparity scores”, in which I simply did basic subtraction to find the disparity between all 130 teams’ Offensive and Defensive SP+ ratings. Northwestern finished second in the entire college football landscape heading into last season, as their 111 ranking displacement was only bested by San Diego State, who clocked in at 112. The two were bestowed similar fates as SDSU was entering that week with a stellar defense that ranked 11th in the nation, but a deadweight offense that slotted in at 123rd in SP+.

Well, shocking as it may be, the Aztecs have done it again. They have beaten the ‘Cats out for the preseason disparity rankings crown by the smallest of margins, upping their gap from 112 to 114, meanwhile Northwestern enters 2021 with the same disparity score as last year — 111.

I want to challenge the actual SDSU Aztec mascot to a fist fight at this point, it’s that frustrating.

As a matter of fact, Northwestern’s offense tried to do what it could in sliding even further down the SP+ rankings to 123rd, one spot lower than San Diego State at 122. The difference, though, was the relative fall of the Wildcats’ defense down to 12th nationally, meanwhile SDSU enters this upcoming season 8th overall in Defensive SP+.

Absolutely maddening.

The point remains, however, that both these schools stand far above the rest (given, it’s not inherently a good thing to finish high upon this list). Washington State enters the season in third despite “only” having an 88-spot different between its offense and defense, putting them a substantial 23 points behind Northwestern. All in all, there are only 25 teams out of 130 that eclipse the 50-point mark, and a good portion of them are non-Power Five teams.

Most college football teams are logical and either consistently good (Alabama), consistently mediocre (Wake Forest) or consistently dreadful (New Mexico State) throughout all facets of their team. Northwestern football is thus the opposite of logic.

Within their own conference it isn’t even close. Michigan State and Purdue are the only schools that come anywhere near the ‘Cats’ knack for disparity, with scores of 75 and 60, respectively.

(Both NU and MSU having far below average offenses crossed with quality defenses is a good reminder to prep for an 11-8 rock fight next Friday).

At the end of the day, there isn’t any grand, sweeping takeaway to glean from all this. Northwestern under Pat Fitzgerald has never been an offensive dynamo, and yet, it’s rare for a team of his to perform below expectations for a whole season.

It’s more just a fun exercise for all us sickos out there to remind ourselves what we’re watching both in this year and in years to come — a bonkers team who is top tier on one side and look-away-they’re-bad on the other, yet in the end come out as a whole greater than the sum of their parts.

There’s Northwestern football and then there’s logical outcomes to reality. The two have never once mixed and probably never will. Bless us all.