Somewhere between “contender” and “pretender,” there’s the repeat offender.

Members of this category are always there, not quite elite but always capable of causing chaos. Toppling the establishment.

Think the Joker in the Dark Knight series, the Bad Boy-era Detroit Pistons or the guy at the office who never tops the quarterly sales charts but is always factoring into the mix.

That’s what Pat Fitzgerald has built at Northwestern.

And for better or for worse, the Wildcats are currently in a class by themselves.

It’s easy — and, on some levels, even logical — to raise an eyebrow at the rankings that came out Sunday, a day after Northwestern seized control in the Big Ten West with a 17-7 victory over then-No. 10 Wisconsin. The program’s official Twitter account tossed some shade in the direction of both the AP poll, where the ‘Cats are ranked 11th, and the coaches’ rankings, which have them at 13th.

Despite one ESPN metric that has Northwestern with FBS’s best “strength of record,” the network’s SP+ predictive analytics list the Wildcats just outside of the Top 25.

The rankings that matter, the College Football Playoff selection committee’s first of the season, come out Tuesday. But it’d be a shock if 5-0 Northwestern cracked the top five let alone four.

You don’t need ESPN college football insider Bill Connelly’s proprietary SP+ algorithms to assess the Wildcats’ Playoff worthiness. You just need to see them take care of business against Michigan State, Minnesota and Illinois then upset Ohio State in the B1G Championship Game Dec. 19.

Until then, Northwestern won’t have proven that it belongs among the likes of Alabama, Clemson, Notre Dame, the Buckeyes and the rest of the contenders.

The No. 4 team in the Playoff has been far behind the top three in recent years (see Oklahoma in 2019 for maybe the most stark example). But is Northwestern really up there with the Fighting Irish, Texas A&M and Florida?

Not quite. Not yet.

This is NO disrespect to what Fitzgerald and his staff have accomplished during 15 years in Evanston. The former Northwestern linebacker has found a way to develop 2-star and 3-star recruits into disciplined, heady, selfless stars.

The school has invested in pristine facilities but still plays in one of the B1G’s most modest stadiums. Its academic entrance standards are some of the nation’s toughest.

The Wildcats’ past 5 recruiting classes haven’t ranked higher than 47th in FBS and 10th in the 14-team B1G, according to 247Sports.

And yet Fitzgerald and coordinator Mike Hankwitz have constructed a defensive juggernaut that ranks 4th in scoring defense and 5th in yards per play this year.

Don’t underestimate this team’s dedication, either. While college football isn’t anywhere near the hottest ticket in Chicagoland, you can tell these kids care deeply. Any program that avoids a COVID-19 breakout should be commended for its adherence to strict protocols every second of every day.

But it’s still too easy to call Northwestern one-dimensional. Its scoring offense ranks 84th, its total offense 106th and its yards per play 120th out of 127 active FBS teams.

Does that matter if no one can score against the Wildcats? Hypothetically, no. But they haven’t faced an offense that ranks higher than 31st in scoring (Iowa) so far.

Their quarterback play from Peyton Ramsey has been better than last year’s abysmal showing but is average at best. They don’t move the ball with ease and sometimes turn it over at the worst times, like Isaiah Bowser’s goal-line fumble Saturday.

But this isn’t so much an indictment of Northwestern based on its faults than it is a statement about the sheer top-heaviness of college football.

Less talented teams pull off upsets all the time, and the Wildcats are built to do it.

But can you really pick them on paper to hang with one of the SEC’s top three teams, or Clemson, or Notre Dame? Even Oregon? That last one’s probably a toss-up at best.

A number of variables dictate each college football program’s ceiling. In clinching the West two out of three years, Northwestern would be butting right up against its roof.

But structures can be overhauled. And if an undefeated Wildcats team scraps past Justin Fields and the Buckeyes a month from now, we’ll be having a much different conversation.

Besides, Northwestern’s at its best when it feels a sense of disrespect, anyway. The Joker of college football has a head coach who’s never afraid to call out doubters — including ESPN analyst Joey Galloway — and defensive backs who abuse opponents’ equipment accessories.

Fitzgerald and his players say this year isn’t a surprise to them.

But take the chip off its shoulder and you take away Northwestern’s identity. If all goes as planned, we’ll get a chance in Indianapolis to see just how far that identity might take this antagonistic bunch. Can the Wildcats break through like those Bad Boy Pistons eventually did?