This page explains how Sai Anish Karthik Sivakumar (USATT# 219237)'s rating went from 30 to 20 at the ICC - Sunday Beginners League event from 21 Jan 2018. 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.