This page explains how Rex Edward Joy (USATT# 17580)'s rating went from 815 to 821 at the Windsor Vermont April 1999 Gia held on - 3 Apr 1999. 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.