This page explains how Michael Sun (USATT# 273013)'s rating went from 1820 to 1821 at the Westchester October 2023 Open held on 28 Oct 2023 - 29 Oct 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.