shortest successful QB that I can ever remember

shortest successful QB that I can ever remember that has had some level of success.

You want to pull for somebody who has overcame great odds, but those odds are still against him maintaining this level of play

1) He can't see because of his height and teams will learn how to use scheme and use that against him.
2) because he can't see, his is going to move around more and take hits and one of those hits will get him from time to time with the injury bug, especially at his size.