This page explains how Krishna Nandakumar (USATT# 229845)'s rating went from 660 to 640 at the ICC - Sunday Beginners League event from 22 Nov 2020. 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.