This page explains how James G. Spetsios (USATT# 10193)'s rating went from 1588 to 1550 at the 2009 Millcreek Giant RR held on - 5 Apr 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.