This page explains how John Chan (USATT# 1167475)'s rating went from 843 to 803 at the 2023 PolDoor Open held on 10 Jun 2023 - 11 Jun 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.