This page explains how David Aaron Katz (USATT# 1291)'s rating went from 1422 to 1421 at the 2006 SpinMania held on - 3 Sep 2006. 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.