This page explains how Jeffrey Von Kohorn (USATT# 76011)'s rating went from 1643 to 1618 at the Westchester 2012 August Open held on - 19 Aug 2012. 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.