This page explains how Joan Rizzo (USATT# 29844)'s rating went from 643 to 638 at the Arizona Sizzler Open held on - 15 Aug 2004. 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.