This page explains how Patrick Keville (USATT# 77971)'s rating went from 1809 to 1774 at the LYTTC Friday Pro League event from 23 Jul 2021. 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.