Seriously - they don't. They have a guess, but it's just a guess.
I support them in whoever they play, but just because they think one thing doesn't mean it's true any more than thinking that a fake punt on 4th and long in your own EZ is good idea. This is a message board to debate ideas as fans. We're not coaches. Coaches know a whole lot more about football than I do, but that doesn't mean they're infallible. Bronco was wrong - a lot. Even Detmer may be wrong - I guarantee you he's second guessed himself more than once about this...