Lots of gamers have, well, game. Johnathan Wendel—a.k.a. Fatal1ty—perhaps the most famous ever, won half a million dollars in prize money competing in now-defunct leagues in the early part of this decade. He too was a high-school athlete, in tennis, golf, and football. But unlike Walshy, Fatal1ty invited animosity from the gaming faithful, mainly because he worked as a lone gunman. Walshy's appeal comes as much from his Everyman charisma as from his dominance. He has a long face, moppy hair, and an easy grin that falls somewhere between giddy and goofy. He drives a 2002 Ford Taurus, has raised $15,000 for autism research, and hopes one day to make video-game consoles as prevalent in hospital rooms as televisions. Mike Sepso, who cofounded MLG in 2002, calls him "a historic figure." Of five MLG national Halo titles, Walshy's teams have won three. And in those years, the league has seen unprecedented growth: six destination tournaments that now lure competitors from more than 25 countries, over 5,000 new online players a day, and sponsors like Ball Park and Old Spice lining up to peddle their wares to a 12-to-34-year-old demographic that doesn't seem to watch TV or read newspapers. More than 503,000 people viewed the Dallas tournament on MLG's website, thanks to broadcast partner ESPN, which has a gaming talk show.

All of which makes it more than a little odd that the league and Walshy's teammates both recently betrayed him.

Last summer, after a rough outing in San Diego, the MLG star stopped hearing from Michael "Strongside" Cavanaugh and the aptly named Ogre twins—Dan and Tom Ryan—from the Final Boss crew, with whom he'd won his three titles. This wasn't entirely unusual, as players live in different parts of the country and convene online to practice. But when Walshy mentioned the silence to a friend, he got this reply: "You haven't heard? You were replaced!"

Walshy's phone calls and text messages went unanswered. "We weren't having fun anymore," explains Ogre 2 (Tom). "We weren't practicing as much. There was some personal conflict." In the absence of an official explanation, the gaming community started buzzing: The Ogres were jealous of Walshy's fame. . . . Walshy discovered a life beyond Halo. . . . An unnamed girl busted up the band. It turned out the league had instructed the Ogres not to tell Walshy about the move until Final Boss's sponsors—Red Bull and NBA star Gilbert Arenas—had been briefed. "We would have called him right away," Ogre 2 says. "We would have made sure he heard from us." An MLG spokesman defends the decision, saying, "Sponsors need to be aware."

Walshy was furious. "That is not how you handle a four-year relationship," he says. Suddenly the league had a Brett Favre-like drama on its hands. Were the Ogres evil? Were Walshy's technical skills less effective in Halo 3? Or, gasp, had he lost a step? He is, after all, a fossil in the final stretch of a three-year, $250,000 contract with the league. "Walshy was our first breakout star," says Matthew Bromberg, MLG's CEO. "He's the granddaddy. But staying on top is hard."