the base trueskill is taken from SPM/KDR, that value is then plugged into an algorithem that is something along the lines of [player TS- opposing player trueskill deaths] + [pts+opts kills]/KDR(or SPM if in an objective game type) If your base trusedkill is low on average, when you preform above it you are granted a loot drop from a randomized pool. People who do consitently well have to try tons harder, but the loot they get comes from a higher ranking pool as well. All this was posted several times in beta and alpha and it ridiclous how many people either dont know or just dont care. The game rewards you for improving, not just being the same skill level all the time.