This page explains how Derrick Cone (USATT# 64672)'s rating went from 1977 to 1939 at the DFWTT TX Winter Games held on - 15 Jan 2011. 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.