This popped up in my Google Reader this morning. It’s just an abstract, but the short answer is that no one really knows. Yup, no one actually knows how human beings are able to predict the landing spot of baseballs in the outfield while running around trying to get under them. It’s pretty clear that we can do it — Daniel Murphy aside — but no one’s 100% sure how, and our brains are complicated.
If you’re really curious about how scientists think we can catch fly balls, this (science heavy) article has what I think is the most widely accepted answer, but it’s science heavy even for me.