To be fair, you would literally have to lose a ton of battles to reach 0 points as its 10% Of your total. 

1000 - 900
900 - 810
810 - 729
729 - So on and so forth

no extra calculations or anything. You most points based off what you go on with, so you don't win a ton of battles in the span of one other then lose more points because of it.