But there's another possible interpretation. Perhaps the particle's spin is completely determined – but depends on something else about the state of the universe. That would be like a player in "Twenty Questions" who has decided his object is a donkey whenever his opponent starts a question with "Is," and that his object a horse otherwise (or using any other arbitrary but consistent rule). For example, if his opponent asked, "Is it something with big ears?" he would say "yes," but if his opponent asked, "Does it have big ears?" he'd say "no." In that case, his answers are predetermined even though he has no single object in mind.

Doesn't this interpretation also apply to two entangled particles separated by a great distance? Couldn't they just be responding to measurements according to the same pre-determined algorithm in their basic nature, without there being any implication for the free will of the observers?