This page explains how Reginald Willis (USATT# 11921)'s rating went from 1875 to 1848 at the Potomac 2013 Fall Open held on - 10 Nov 2013. 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.