Not really. Most teams leave their starters in for only 1 qtr, in order to keep them from getting injured and also they need to see what their back-ups can do, before the have to make cuts.systems aside, if one was to play the over in pre-season wouldn't it make sense to play the first half over assuming the starters would be playing little or none in the second half ?
Take last nights game, if GB was to lose Rogers to an injury, then what will they do if they don't know what back-up is better in a game situation.( by the way, neither are any good) They would probably look to trade for a QB, pick one off the waiver wire ( like the Steelers just did) or rebuild and figure not to be in any position to make the playoffs.
I only bet $50-$100 on any pre-season game, because they are so unpredictable.