Do you have a specific example of this?
The best example I can think of are banks that, on paper, shouldn't go, but do (bending the object ball is what I'm getting at). Yea, it can be figured out mathematically (although I don't have a clue how), but who the hell wants to do all that? I'd rather do something more fun like drink beer or watch someone actually bank it in.

Another simple example is the "tit" shot, where the object ball is on the tit frozen. It goes straight in the side if hit dead straight with speed. Everyone knows that you are compressing the cushion but I wouldn't have a clue as to "show" that one paper. It just goes.