This page explains how Stanley Harn (USATT# 25840)'s rating went from 1617 to 1615 at the Chicago Land Area Singles League event from 1 Jul 2013. 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.