There's an old Exhibition disc that had G4 TV's footage of a Halo tourny they put on back in the day. Let's just say none of the players really stand out as being all that impressive. They didn't really use any game modes that would really allow for domination though. I think that every tourny should have at least ONE round where they play with no shields so the headshot masters can shine. To me, that's scary fuckin talent.
