The old axiom that it takes five years to develop a top notch NFL quarterback has been skewed by the likes of big Ben, Payton, and, definitely, Marino. But they are exceptions moreso than anything else. Look at guys like Steve Young, who spent years as a second fiddle, learning the game, and Trent Green. And Johnny U. bumped around for a while, as did Brett.
JP may not be the answer. But eight games isn't five years, according to my calculator.