This page explains how Jeffrey Von Kohorn (USATT# 76011)'s rating went from 980 to 946 at the Quincy September Open held on - 21 Sep 2008. 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.