Aside from being 6-12 over his last 18 games (yes, crapping the bed in '11 when playoffs were stilll a possibility, and an impressive 52 turrnovers over the last 2 complete seasons.....putting "he's shown he can win" into perspective, by comparison
Rex Grossman: 6-11 over last 17 starts (mostly for worse Washington teams)
Sanchez: 62Games Played
Same difference - aside from Grossman not failing to win a Conference and smell a world Championship. And no, IMO, there aren't any NFL teams who would look at either as starting material to build around at this point.