I think "very little" is a big exaggeration. Some players perform completely different (for better or for worse), but practice is still a very good indicator.
I think that it can be a very good indicator. But how can you ever evaluate true gamesmanship in practice? If Flynn has been capable of doing the things he did Friday night all along, what was it in practice that gave JR the edge? More over, what was it that he did that gave Flynn such minimal time this year? If the QB race was as close as they said it was, why was there such a tremendous disparity in PT?
Word is that Miles doesn't like to put in 2nd string until the game is solidly in hand. We didn't get that very often this season. Thus, Flynn didn't get much PT. Also, as you mentioned earlier, why mess with a winning formula? JaMarcus was a proven winner... even if it wasn't pretty. You didn't see very many Flynn supporters after the SECCG did you? One game is not enough to judge a QB on. I love how people are suddenly completely over looking that SECCG based on how it was "unwinnable" & only point to the references that support their belief. Just because Flynn is capable of doing the things he did Friday night (even consistently) does not mean that he is the better QB. We will never know how well a healthy JaMarcus would have done in his situation. The whole team played better. Flynn's stats weren't great (although very impressive, especially considering the competition - not as god-like as some make it sound). The assumption around here seems to be that JaMarcus could not have done as good of a job - I'd have to disagree.
I look at individual plays and ask myself "could JR have done that?" I find myself saying "no" quite a bit after watching the game three times. Certainly JR couldn't have taken off on those three occassions when Flynn did. Or he might have, but he gets caught way earlier. Could he have used his speed to roll out of the pocket and just dump the ball off? I don't think so. Could he have placed the ball better? Not over the course of the whole game. He always throws in some bizarre foot scrapers among his pretty passes. Could he have managed his time better? JR is often looking at the D and seeing something that causes him to call a timeout. None of that the other night. Delay of game? Hasnt' that been called on us quite a bit this year? Not once the other night. There are several glaring differences.
