Purely speculations though, I don't have access to the code to verify it.
I don't either but I'd be extremely surprised if it actually does pick a winner at the start. That's absolutely the wrong way to do it. It most certainly would not take "a lot of CPU" to do it properly.
In comparison I'm sure the difference would be quite big (at very small levels)!
What kind of logic are you thinking would be implemented? I can only imagine it being more difficult to figure out which not to call than which to call.