This page explains how Des Preston (USATT# 73084)'s rating went from 2091 to 2066 at the Westchester 2015 June Open held on - 28 Jun 2015. 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.