This page explains how David Guan (USATT# 217271)'s rating went from 1559 to 1521 at the MDTTC November Open 2023 held on 18 Nov 2023 - 19 Nov 2023. 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.