This page explains how JIAN Mao (USATT# 272209)'s rating went from 668 to 661 at the HITTA Weekly League event from 11 Feb 2022. 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.