This page explains how David Y Yoo (USATT# 96977)'s rating went from 1492 to 1491 at the Westchester October 2018 Open held on 27 Oct 2018 - 28 Oct 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.