This page explains how Li Gao (USATT# 220076)'s rating went from 1563 to 1551 at the HITTA Weekly League event from 27 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.