This page explains how John Bacon (USATT# 266638)'s rating went from 818 to 481 at the ICC JOOLA Winter Open held on 8 Nov 2019 - 10 Nov 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.