You realize all your system appears to do is the same thing the bookies are doing? It simply picks the favorite to win the game, which is what the bookie does and sets their line accordingly. All year you have bet on a total of 8 underdogs. Your picks record may well end up over 50% but I would bet you my life that your % system is going to run you broke if you continue to merely bet on whoever your system puts at over 50% to win. They may win more than 50% of the time, but when you are paying 1.75 it takes more than just winning 50-55% of the time to come out ahead.
Don't mean to hate on your system, but IMHO its simply doing what the book already does...picking out the favorites. If it took the probability and adjusted for the price of the line, thus telling you whether the value is on the favorite or the dog in a particular match, then you might have something to go on. As it sits, this looks like doom on any night when the dogs are barking.