let's put aside that many pundits claim pre-season games have limited utility. how much gametime is needed? I believe others have been asking the same question. Don't forget, keep your starting QB in there...you have to keep the other starters. Change the line-up enough and you are not learning under conditions that reflect real games.
Every player is different. Griffin, starting from scratch essentially learning a pro-style offense, was set back even further with the offense we used it 2012. I'm not looking a gift horse in the mouth here, it was one of the most amazing things I've ever experienced as a Redskins fan, and I hold that near and dear to my heart. That being said, the way he's been handled by an NFL organization has not been the best and imho has potentially killed his chances of ever being a true star in the NFL.
Looking at his history, his whole 1st offseason and regular season, we ran a read option base with some other things mixed in, but the emphasis on developing into a pocket QB was not there.
Year 2 he was hurt, coming back after the ACL so the offseason of field practice time, as well as live fire reps in the preseason was shot. Completely lost.
Year 3 he breaks his ankle week 2.
How much actual time has he had to learn these things in physical game situations? He's a 4 year QB who has had 30+ starts but clearly has not mastered the art during the regular seasons that he's been in. If he has any hope of doing anything different here, he's going to have to prove it in the games. He's practiced well, we've heard the right things in camp, but it's not translating to game speed.
How much game time is needed? Until he gets it or moves on. As long as he's the starter, I think he needs more game time.