This page explains how Xianzhong Chen (USATT# 25249)'s rating went from 1887 to 1821 at the Westchester May 2018 Open held on 26 May 2018 - 27 May 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.