The why is everything. That's the ethos of Kyle Shanahan, son of a coaching legend and now the leading figure in a revolution that is sweeping the league. Shanahan and the branches of his coaching "tree"--including Sean McVay, Mike McDaniel, Raheem Morris, and Matt LaFleur--came up in a martial sport where coaches and players did things a certain way for the simple reason that coaches and players had always done them that way. In the early 2010s,...