I've seen two things happen in the year or so i've been playing:
1)Its the same names on the board, for the most part and, while this is just an observation on my part and may be way off base, 2) Its more about friends beating on each other so they can collect a little chy than it is about rivalries and desperation.
I have a feeling that's why we miss months of participation in the event and that sucks. Even if i can't go OOCly my character always loved catching up on the fights. Who beat who. How badly. etc. etc.and she still even participated -kinda.
One idea i had to boost some life into the games is this:
Have admin (if they wanted to) or trusted players even, roll characters just for the fights. Add bodies. Add flavor. Conflict. RP. Maybe they're coming in from East Red just for their shot at fame. They can be weak, strong, whatever, just something to get the blood splattering. If they beat a PC char, big deal. Come back next month and kick his ass. Start a feud. It shouldn't be a fraternity or even a fight club, it should be a blood sport.
I know that's opening up a whole can of worms by having additional characters with little or no backgrounds or further RP outside the fight nights and adds work for admin, but its not work if you have fun doing it. I wrote a little snapshot about the UMC a few months ago that nobody commented on, so maybe i'm just stuck on this for some reason and nobody else really cares or sees it as an issue. I guess i just see it as a missed opportunity. I'd love to hear from people whose char's are invested in it though. Is it fine the way it is?