This page explains how Qi Guo (USATT# 80876)'s rating went from 1949 to 1924 at the LYTTC December Open held on - 16 Dec 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.