This page explains how Alan Tang (USATT# 81663)'s rating went from 2138 to 2131 at the Swan Friday O2000 Team League event from 22 Sep 2017. The links below take you to pages that describe various aspects of the rating processor.

The rating processor goes through 4 passes in order. The links take you to pages that provide detailed explanations of the calculations during each of the 4 passes.