To understand Bill Belichick you Need to google and read about his father Steve who was an Assistant Coach & Scout for Navy at Annappolis for more than 30 years.
Bill was learning from his father how to study film when he was 10 years old! He is the greatest NFL coach of his generation because he has been studying the game for more than fifty years with a laser like focus that most don’t appreciate...
Second, Belichick is supremely self-confident. So much so that he doesn't feel the need to brag about how smart he is. Which means that he never talks about the innovations he has come up with and he is perfectly willing to keep secret innovations which allow him to keep winning. In the case of the fumble rate, it looks like starting in 2007, Belichick figured out how to change the game by changing how the Patriots approached fumbles. Since then, you haven't heard a peep out of Belichick on this innovation even though most other coaches would have been falling all over themselves to brag about how clever they were in coming up with a similar innovation.
I love Bill. He puts a strong emphasis on having a smart team according to their test scores. He ll be playing a team hyped up on speed sunday night.