This page explains how David Guan (USATT# 217271)'s rating went from 1083 to 1071 at the HCTT Players Development League event from 12 Jan 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.