Michael Huff was a good example of that phenomena. Went from un-starred to 4-starred the moment he committed to us.
It kind of has to be biased towards the good BCS schools, otherwise there would be no way to rank the classes the way all of the services do. You take the kid's 40-time, height, weight, and offers. That's pretty much all you can go on, because anything can happen regarding position changes, injuries, HS team ineptitude, etc. If a guy is beyond awesome on the field, but only has offers from SMU, San Diego State, and Hofstra, then of course he's not going to be 4/5 star.