This page explains how Reginald Willis (USATT# 11921)'s rating went from 1849 to 1811 at the MDTTC Butterfly October Open held on - 21 Oct 2007. 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.