This page explains how Michael Guo (USATT# 221417)'s rating went from 2139 to 2123 at the ICC JOOLA SUMMER OPEN- 2021 held on 29 May 2021 - 30 May 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.