This page explains how Adam Fan (USATT# 217518)'s rating went from 1200 to 1121 at the HCTT Players Development League event from 1 Dec 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.