This page explains how Sean Ling (USATT# 199400)'s rating went from 1275 to 1179 at the ICC - Sunday Beginners League event from 17 Dec 2017. 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.