This page explains how Jingfan Feng (USATT# 219191)'s rating went from 690 to 688 at the ICC - Sunday Beginners League event from 15 Sep 2019. 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.