For the most part actors do one film at a time, some get signed for three, maybe tops five film contract. An NBA player like Rose gets a seven year contract and you have no way out. It is the owners fault though in the end, they are idiots for some of the contracts they give out.
Look at the NFL Reggie Bush never did anything, he got about 25 million guranteed, if he blows out his knee tomorrow he keeps that money and the Saints are screwed.
If it wasnt for gambling, I wouldnt give a damn about any pro sports.