This page explains how Ian Seidenfeld (USATT# 80503)'s rating went from 941 to 939 at the Bloomington Armory Community League event from 24 Sep 2012. 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.