I know its easy to say after the game is over, but personally I think one has to be out of his mind to play an UNDER when the total is set at 6 such as was the case with the San Diego and Toronto game on Tuesday.
Too many things can happen, amd remember games don't end in ties meaning that if score is tied at 3-3, which really isn't that difficult to happen, you are a loser.
I don't have the stats, but overall I would bet that over time when total is set at 6 or even 6 1/2, one would be better served by playing the over in these games or at the very least passing on the game and staying away from the under.