This page explains how Bill Ukapatayasakul (USATT# 10729)'s rating went from 1987 to 1983 at the 2010 US Open held on - 3 Jul 2010. 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.