This page explains how Jiangshan Guo (USATT# 214856)'s rating went from 2431 to 2366 at the Westchester September 2023 Open held on 23 Sep 2023 - 24 Sep 2023. 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.