This page explains how Mohammed Yasin Musthafa (USATT# 219888)'s rating went from 1720 to 1670 at the ICC - Sunday Beginners League event from 5 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.