This Buffalo fan doesn't consider Sanchez a "joke" but I would NOT surprised if he never develops into a franchise QB. Right now, he hasn't been impressive at all. He was okay for rookie QB, but if he were playing for a team with a weaker D and a lesser running game, I think he'd be very controversial. Sanchez looked great against weak Ds last season but stunk it up against top Ds. The last sophomore QB who played the Dr Jekyll and Hyde game in that manner was the Bills' Trent Edwards, and he got dumped (finally!) last season. I don't think that Sanchez has the same issues that Edwards had/has but I don't think that Sanchez has developed as fast or as well as expected. He seems to have difficulty throwing accurately downfield, and he seems to rely too much on checkdowns, which says he hasn't mastered reading defenses all that well. I don't think he's nearly as far along in his development as Matty Ice or Joe Flacco were after their sophomore seasons. Whether Sanchez becomes a franchise QB or not depends upon whether he continues to develop from where he is now. I think if he does NOT step up and become elite in the next year, he will be seen as a disappointment.
