This page explains how Joe Yuan (USATT# 90498)'s rating went from 639 to 639 at the SVTTC Sunday U2000 event from 11 Nov 2012. 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.