This page explains how Alan Tang (USATT# 81663)'s rating went from 2112 to 2031 at the Swan Friday O2000 Team League event from 9 Jan 2015. 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.