This page explains how Derrick Cone (USATT# 64672)'s rating went from 2048 to 2020 at the 2009 Winter Grand Canyon State held on - 29 Mar 2009. 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.