I'm not a believer in starting a rookie QB. It's not that some haven't been successful; but the odds are small.
I don't know how good Washington's offensive line is, and if they have the type of players to surround a young QB with that would allow him to grow and succeed. Choosing Case tells me they probably don't think they do. Or that Haskins is just not mentally ready for NFL play (that doesn't mean that the young man won't eventually succeed).
But one has to wonder just how much longer Gruden is going to be allowed to run the team if he doesn't show some success, which is probably defined as winning the division and thus getting into the playoffs. The Redskins have been the model of mediocrity for some time, now.
