I would like to see the contract language. I wonder if it is exclusive for mma or for fighting in general. Furthermore, if Anderson breached his contract and fought Jones anyways, it would be an efficient breach because he would make millions of dollars for boxing Roy Jones, and I doubt the UFC would be able to prove that his breach produced damages at anywhere near that amount. If the contract has a non-compete clause the UFC would try to get an injunction to prevent Anderson from fighting, but most courts are loathe to enforce non-compete clauses, especially if there is language in the contract that is patently unfair, such as the UFC's champion clause (which was in Randy's contract) which says that a UFC champion cannot leave while a champion, and has to automatically resign for the same amount of money as he was previously making. That is unconscionable, and assuming that same language is in Anderson's contract, a judge might void his contract with the UFC entirely.