The San Francisco 49ers appeared to overachieve on offense during Jim Harbaugh's first two seasons due to impressive creativity and unpredictability.

But opposing defenses have seemingly caught up to Harbaugh and Greg Roman's ingenuity.

"Defenses are doing a great job on us, game-planning for us," Frank Gore said.

The 49ers have one of the more voluminous and complex playbooks in the NFL.

"We've been doing great on the running game, so everybody's going to try to stop the run," Gore said. "That's what's been happening."