This page explains how Don Richer (USATT# 77292)'s rating went from 1239 to 1225 at the 2018 Arizona Open & Giant Round Robin held on 24 Feb 2018 - 25 Feb 2018. 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.