From Chris Brown at Grantland.com: http://www.grantland.com/story/_/id/9508313/after-offseason-searching-nfl-coaches-know-how-defend-read-option
Very interesting read. Here's a tidbit:
"Read-option plays force defenses to approach reacting to offenses much differently. With traditional approaches, the quarterback knows before the play whether he will either hand the ball off or keep it. In the read-option, the quarterback, typically aligned in the shotgun, will "read" the movements of a particular defensive player, one the offense has specifically chosen not to block. It's based on this player's actions that the quarterback makes his decision — hence the (redundant) term "read-option." "Whenever the guy who takes the snap is a threat to run, it changes all the math of defenses," Tampa Bay Buccaneers head coach Greg Schiano said in 2012. "It changes the numbers — minus one." Last season, many NFL defenses repeatedly failed this basic calculus and tried to defend run games with six to eight offensive threats — blockers or potential runners — while undermanned by one, two, or even three defenders."