This page explains how Bill Draper (USATT# 215512)'s rating went from 1560 to 1551 at the MDTTC Tuesday/Friday League event from 6 Sep 2019. 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.