This page explains how Joe Pierotti (USATT# 16090)'s rating went from 1599 to 1580 at the AZ PTTC Monday event from 7 Mar 2011. 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.