This page explains how Trung Nguyen (USATT# 198533)'s rating went from 1839 to 1821 at the BTTC League event from 21 May 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.