This page explains how Anh Quoc Duy Nguyen (USATT# 91361)'s rating went from 1823 to 1819 at the OCTTA BUTTERFLY FIRST ANNUAL SENIORS OPEN held on 6 Oct 2023 - 8 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.