Well i didn't know where to post this question, so forgive me if this is off topic.
I want to ask for the complete method for calculating the BKR in the games of Chess, Gothic Chess and Backgammon. I know that it's the same with that of the US Chess Federation formula, but calculating it this way, the results are not the same. So something must be different. Can a knowledgeable (Fencer or anyone else...) person solve my question?

Thanks.