Experience is broken, you can lose XP on a win. AI characters seem to adversely effect the calculations cause they are ranked very high, with an AI teammate a loss is devastating to your rank cause one on your team was super pro. Even a win with an AI teammate is pretty ordinary, prolly cause your partner was super pro, you should have won anyway.
Much better to enjoy the losing streak on a cool toon with a BS spec just cause it's fun:P Yeah, I'm talking to you Torch Bearer:P