This page explains how Xianzhong Chen (USATT# 25249)'s rating went from 1909 to 1874 at the 2021 PA State TT Championships held on 30 Apr 2021 - 1 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.