The assumption should be he is the guy for the full season. However, in the event he struggles game to game, or shows no additional growth or consistency, by mid year a change may be warranted. For me it is all about showing progress. This is still a learning year, but one in which I, and I assume the team, expect to see evidence of improvement. He will have bad games, bad quarters, bad series, etc, but does the overall body of work indicate a guy that is growing, getting it, or not. It could certainly go either way, but I expect this is precisely what he will show. Despite the farmers with pitchforks around here assuming he will fail, or waiting for him to fail, the Bills will give him every opportunity. There will be no quick hook, nor should there be.
Until half time the first game, huh? You need to adjust your expectations.