Article About the Evolution of the Shanahan System and What Makes it Work

So I read the article and think I sorta understand it.

The classic Shanahan offense is very much Wide zone- counter - bootleg centric. The wide zone is core, the bootleg and and counter act as counter punches which look the same as the wide zone and attack the backside end in different ways to keep him honest. Houston ran something very close to this with Arian Foster. When defenders see certain movement, they act quickly to defend against the wide zone, putting them out of position for the counter punches.

What Shanahan the younger is doing is maintaining elements of that core, but now is more often achieving the same effect (of getting defenders out of position) by manipulating the defenses with pre-snap formational threat and motion, enabled by a group of players with multi-positional flexibility.