In mixed martial arts, the fanbase is divided into two camps — “hardcores” and “casuals.”

“Casuals” are fans who were late to jump on the MMA bandwagon and are most prone to respond to big names. They know Brock Lesnar, but they’re a little hazy on Cain Velasquez. They aren’t well-versed in the grappling aspects of MMA. For a while, the dividing line was after the Forrest Griffin-Stephan Bonnar fight in 2005 that propelled the UFC to greater heights.

“Hardcores” can earn their credentials in a few different ways. They might be experts in technique, either striking or grappling. They may have been around since the days of Pancrase or at least Pride’s heyday. They’re not homogeneous — some appreciate the pro wrestling roots of Japanese MMA, some hate pro wrestling and want MMA to strive for legitimacy and professionalism akin to other major sports. They’ll argue about the sport’s history the same way college-rock diehards will argue whether Automatic for the People was R.E.M.’s masterpiece or further evidence that they’d sold out.

In the EliteXC days, the UFC was the hardcore fans’ choice. EliteXC was betting the farm on the lie that Kimbo Slice was one of the world’s best heavyweights. Not even Kimbo believed that. The UFC was mostly a meritocracy. Some fans insisted that the UFC merely had some of the world’s best talent, not all of it, but the UFC was not something to ignore. The title belts meant something.

The Ultimate Fighter has often divided hardcores. The first season yielded the spectacular Griffin-Bonnar fight and several legitimate UFC stars, so even if hardcores scoffed at the drunken shenanigans in the house, they were willing to pay attention. As the TUF talent has grown weaker, hardcores have been more likely to say, “Oh, I haven’t watched since the fifth season.” They may have come back for the heavyweight season, which mixed in a few good prospects along with a true test of Kimbo Slice’s fighting skills, and the featherweight/bantamweight season drew a lot of curious looks at a largely untapped talent pool. But beyond that, the hardcores are an audience that would need to be won back.

The 15th season (first on FX) was designed to do just that. The fights were live. The drama in the house was toned down. It was less of a reality show and more of a tournament for prospects that played out in real time. But the ratings weren’t great. Perhaps the new Friday night time slot was a problem, though I’m inclined to think hardcores know how to work a DVR.

Season 16 went back to the old format, and the promos showed plenty of confrontations in the house. Honestly, I thought the ratings would go back up, capturing people who may claimed they didn’t like reality-show nonsense but secretly craved it. That hasn’t happened.

And that brings us to the week’s blockbuster news: Chael Sonnen and Jon Jones will be the coaches on the show’s 17th season. Then Sonnen, who has never won a UFC fight at light heavyweight, will fight Jones for the light heavyweight title.

I responded on Bloody Elbow with a flippant comment that “There are no hard-cores.” I thought I had explained a bit more, saying that the UFC must think there are no hardcores (I decided to drop the hyphen after looking around for common usage) if they’re just going emphasize Sonnen’s big mouth over a legit title contender, but I see now that I must have hit “send” before typing the rest. Oops. No wonder I got called out on the board and on Twitter.

Coincidentally, I talked with a colleague yesterday who has been around since the old days, and we talked about the size of the hardcore audience. It’s hard to pin down. Hardcores have kept up a lively presence on the Internet, with thriving news sites and a multitude of blogs. But what percentage of the audience is hardcore?

My colleague thinks hardcores’ enthusiasm has dimmed as the UFC has spread itself too thin, putting together weaker cards. I’m torn. Sure, the UFC has come up with some remarkably weak co-main events and third fights on the main card, leading to the cancellation of a major pay-per-view card when the Jones-Dan Henderson fight fell through and left nothing viable to call a main event. But shouldn’t hardcores also be interested in seeing fighters on their way up the ladder? Aren’t they the ones who hop on Facebook three hours before a pay-per-view so they can watch the prelims?

That takes us back to this question: Should we define “hardcores” as people who want to watch as many fights as they can, or are they people who just want to concentrate on the proven or promising fighters?

The next question: Is the TUF audience hardcore, and are they tuning out because they think the fighters have no future? Or is it casual, and have they tuned out because they’ve seen all the reality drama before?

Then what about the Bellator audience? Are they hardcores? And will they watch as Spike puts together another reality show that sounds an awful lot like The Ultimate Fighter but with Bellator rather than the UFC as the prize at the end? (Or do Bellator and Spike think casuals are so habituated to watching MMA on Spike that they won’t notice the brand name has changed?)

“Casuals” may be easier to predict. Give them a big name and an outsized personality, and they’ll respond. But that buzz has to come from somewhere — if their hardcore-leaning buddies aren’t telling them they need to check out Ben Henderson, they won’t. And the hardcores are a little more difficult to predict. They’re a temperamental bunch, and I say that with a lot of respect.**

The good news about the hardcore audience is that they’re not going to go away. Casuals may come and go, but hardcores have too much respect for the sport to abandon it entirely. The danger for the UFC is that hardcore fans are willing to look beyond it.

So I don’t know how big the hardcore audience really is. But I know they’re important. And I know stunts like Sonnen on TUF will not make them happy.

* – Apologies if the headline gets that awful Paula Cole song stuck in your head.

** – Am I a hardcore? Honestly, I’d feel like a poser if I claimed that. I may have been one of the first mainstream sports guys to catch on to the sport — I was USA TODAY’s first official beat writer — and I’ve gone back to watch everything from the first four UFC cards to every TUF episode. But I was lucky to work with Sergio Non, who had an encyclopedic knowledge of every fighter from at least the past 12 years. I have other colleagues in the media who can go point-by-point through the finer elements of jiu-jitsu or covered UFC cards when the sport was still virtually underground. I can go beyond the big names — some of the best fight cards I’ve seen were WEC cards that didn’t draw many other viewers on Versus — but I know my limitations. And I hate pro wrestling.