This page explains how Huanhong Xia (USATT# 266435)'s rating went from 648 to 637 at the 2021 August Open @ Princeton Pong held on 7 Aug 2021 - 8 Aug 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.