Former NFL head coach Bill Belichick in his new book shares a "controversial" take on how Tom Brady and Patrick Mahomes each handled success in their respective career.

A recently leaked email from Bill Belichick to his girlfriend, Jordon Hudson, and the rest of his camp did more than divulge the legendary coach’s public-relations tactics for his upcoming book.

"[Tom] Brady and Patrick Mahomes are both really good," the head coach writes in his new book. "Controversial, I know."