This page explains how Jackson Chen (USATT# 215309)'s rating went from 1126 to 1121 at the Westchester 2021 July Open held on 24 Jul 2021 - 25 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.