This page explains how Joseph S. Helfand (USATT# 6564)'s rating went from 1400 to 1380 at the Davison Athletic Club June Ope held on - 27 Jun 2009. 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.