It's October 27th, 2008, and in Chicago, it seems it's already Halloween. Fighters who have come for the open tryouts for season nine of The Ultimate Fighter, Spike TV's hit mixed martial arts (MMA) reality show, are swarming the Crowne Plaza O'Hare hotel. Some look like seasoned MMA combatants with their shaved heads, cauliflowered ears, and scarred eyebrows. Others look like, well, anything but. One aspirant walks around dressed in a Superman costume, complete with foam muscles, while another is channeling Apollo Creed from Rocky by wearing an afro and an Uncle Sam outfit. By the end of the day, after a scrutinizing evaluation, 16 fighters will be eligible to go to Las Vegas to tape the show, where the chance to become overnight celebrities in the Ultimate Fighting Championship (UFC) awaits.

Debuting in January 2005, The Ultimate Fighter was an instant success (its season finale commanded over two million viewers), launching the careers of future light-heavyweight champion Forrest Griffin and top contenders Diego Sanchez and Kenny Florian. TUF, as it's known, has been credited with almost single-handedly transforming mixed martial arts from an infamous fringe spectacle to a mainstream sport, now considered to be usurping boxing and closely tied to the all-important 18-34 male advertising demographic. Four years and eight seasons later, the show—which follows two competing teams of UFC hopefuls as they live and train together to win qualifying matches and earn a six-figure contract with the league—is still kicking ass. "This is the biggest turnout we've ever had," said Brian Diamond, Spike TV's senior vice president of sports and specials of the 700-plus applicants. "The show is growing, and the sport is growing."

This season, TUF's teams will be split into American and British fighters for a US vs. UK theme. "The last time we went to the UK [to look for fighters]," says Diamond, "we got [current top middleweight] Michael Bisping, and only about 40 guys showed up for the tryouts. This time, we had five times that . . . From a television perspective, we thought it was a great rivalry."

Michael Bisping

The UK tryouts were held in England the week before, and though the results are kept secret, 16 fighters will represent their homeland just as 16 Americans will be picked on this day. Once in Las Vegas, preliminary bouts will be held on the show's first few episodes to whittle the group down to eight fighters for each team—four in each weight class, which this season is welterweight (170 pounds) and lightweight (155). Bisping will captain the UK team. Top-ranked middleweight Dan Henderson will lead the Americans.