Skins quarterback Robert Griffin III led the way last season by reading opposition defenses, but Shanahan said that it will not nearly be as effective for 2013.
"When you have something that was that successful, guys are too smart," Shanahan told NFL.com. "They are going to work all off-season and find a way to stop it.
"And when that happens you got to better at the other stuff. And I think we do have other stuff. And I think we're getting better at it.
"The thing about last year: a lot of people weren't ready for it at all. It was easy at times. Now, it doesn't mean that it doesn't work. You just aren't shocking people like you were last year."
The Skins have lost their opening three games of the new NFL season.