This page explains how James R. Hill (USATT# 70650)'s rating went from 1530 to 1421 at the 2019 US Nationals held on 30 Jun 2019 - 5 Jul 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.