Well I did a search on Board Game Geek (BGG) and found 0 results for Ultimate Fighting Championship (UFC).
I am currently working on a Deck-Building Game (DBG) and have been thinking that a UFC DBG could maybe be possible...
Something like the piles you BUY from are different forms of Combat like Mixed Martial Arts. One pile could be Boxing (Hook, Jab, Uppercut, etc.) and another pile could be Wrestling (Pile Driver, Nelson, etc). Players choose WHICH MOVES they want to have in their DECK!
Using a RPS-5 (Rock-Paper-Scissors-Lizard-Spock) moves can cancel each other out or make one player the aggressor (and costs health points to the opponent).
Both players roll 1d6 to determine the type of move they can do and then must anticipate what the opponent will choose to do next based on their dice roll... Your goal would be to have a GOOD MIX of moves (balance of the deck) to be able to counter.
Your goal would be to reduce the opponent's Health Points to 0.
This is just an idea... But I think it's kinda fun. I think this kind of DUAL game might be interesting to play.
When I check MMA I only get http://www.boardgamegeek.com/boardgame/67816/mma-master
So one (1) result. But it kinda looks like a PROTOTYPE, not a finished game... It says published in 2010, however the look of the game seems to be less than what I would expect from a published game.
In my version, I would OMIT the ring and go with something like three (3) card "melding"* to try to create combos. I obviously would need to do much research into the subject matter before having a game which is comparable to a UFC battle...
*Special thanks to Corsaire for teaching me the word "melding"! :)