It's a system that values every possession. There isn't a sport, especially one with a clock, where every possession is equal. So if Duke beats somebody by 50 playing all their main players is it better than Kentucky only winning by 25 against a similar opponent letting their walkons play? And a coach trying to work on zone defense could hurt his teams defensive efficiency, because he is working on something in December to prepare for February as opposed to just letting man to man continue to crush a team. Then there's a luck factor which is just crazy in itself. Maybe it's the best system going, but some of it is absurd. I'd rather RPI, let the questions did you win and who did you beat be the biggest factors.