This page explains how John Van Deursen (USATT# 36773)'s rating went from 1689 to 1560 at the 2007 JOOLA N. American Teams O held on - 25 Nov 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.