This page explains how Gordon MacDowell (USATT# 65540)'s rating went from 1644 to 1623 at the Valley of the Sun Open held on - 6 Dec 1998. 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.