This page explains how Toon Siong Mao (USATT# 55611)'s rating went from 1848 to 1821 at the San Francisco Summer Open held on - 15 Aug 2004. 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.