This page explains how Evan Warner (USATT# 221335)'s rating went from 893 to 884 at the Westchester December 2018 Open held on 29 Dec 2018 - 30 Dec 2018. 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.