The tumultuousrun of The Ultimate Fighter on FX will go in a different direction for the 17th season of the series. The next season, with coaches Jon Jones and Chael Sonnen, will shift from Friday to Tuesday, and will be starting an hour earlier at 9 PM as opposed to the 10 PM timeslot that the show has been synonymous with for years.
Ratings for the two seasons of The Ultimate Fighter on FX have been a disaster on Friday nights. Season 15 that took place in the spring with a brand new live format regularly failed to draw one million viewers per episode, including the final five episodes of the season (excluding the live, fight-laden finale). Season 16, currently taking place, has seen ratings drop even further. Of the 11 episodes to air so far this season, only two have topped one million viewers. Considering that during the show's 14 seasons on Spike, each episode averaged 1.7 million viewers, the dropoff since the UFC has shifted to FX has been dramatic.
By shifting to the new Tuesday timeslot, FX and the UFC will be using The Ultimate Fighter as a lead-in for two of FX's top original series, Justified (in the spring) and Sons of Anarchy (in the fall). Both have been ratings smashes for the network (especially Sons of Anarchy), and FX is likely hoping that they'll be able to create a two hour block where both shows can sustain two million viewers during the entirety of it.
However, if the ratings for The Ultimate Fighter don't increase, FX will be in a tough position. You've got a well-established show that is running out of ideas and originality, but is run by one of your flagship sports enterprises. I don't think there's any way that FX would be willing to just walk away from the show, but if the ratings keep plummeting, I don't see how they can keep airing the show in a prime slot like they are when it continually lags behind the rest of FX's original programming.
Furthermore, I don't think this is a problem with the popularity of the UFC. The show's format is stale and played out, and the show hasn't really turned out a new superstar since maybe Ryan Bader in season eight (four years ago) or Roy Nelson in season ten (three years ago). Considering that neither of those two really qualifies as much of a superstar...yeah, the show's format is in trouble. It's a different time in MMA now than when the show launched back in 2005. The diamonds in the rough from the first season of the show like Josh Koscheck, Diego Sanchez, Chris Leben, and Forrest Griffin are now guys that the UFC just signs right away and throws onto cards as opposed to putting them on The Ultimate Fighter and forcing them to work their way to a contract. That's not necessarily a bad thing, it's just the way the fight world works now.