Why are you only playing dogs that are +3 or more?  By looking at the numbers, I think it makes more sense to play on all dogs from +1 to +10.  I only saw a couple dogs of +10 or more win straight up (Ohio St. & Wyoming).  I'm considering playing exactly what you did, only throwing out Rutgers, Nebraska, and Arkansas St. Although, Rutgers & Nebraska are borderline.  I am also curious of what lines you are using for your data, opening or closing.  All feedback will be appreciated.