the multiplier adds up correctly (for example in solo its +4 for 1st, -1.3 for the others. if you add -1.3 -1.3 -1.3 you get -3.9 (obviously the -1.3 is rounded because you cant have an infinite decimal in a text box but unrounded you get -4 which exactly cancels)
it's just the actual rating that doesn't and that's because the multiplier works differently for different players because they have different ratings
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