This page explains how Derrick Phan (USATT# 91909)'s rating went from 2040 to 1984 at the Swan Sunday League event from 29 Sep 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.