I really haven't come up with a good way to pick the sides at 2H. If you have a system please let us know.
I look at the public betting percentage prior to the game and bet against the public at the 2H if the chalk is losing. I assume that the public team will get the action again at 2H and the books know this so they will give the non-public team an extra point or two which is huge with only 30 minutes to play.