This page explains how Hsu-Chang Lu (USATT# 84845)'s rating went from 1820 to 1840 at the LYTTC Friday Pro League event from 10 Sep 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.