This page explains how Mark Johnson (USATT# 26863)'s rating went from 1938 to 1921 at the Lunar New Year's Open held on - 11 Feb 2007. 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.