This page explains how Qi Guo (USATT# 80876)'s rating went from 800 to 793 at the NJTTC Monday League event from 12 Oct 2009. 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.