This page explains how David P. Peterson (USATT# 31488)'s rating went from 1580 to 1569 at the Rush Copley Fall Open held on - 25 Sep 2010. 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.