This page explains how Italo Ivaldi (USATT# 1361)'s rating went from 1645 to 1622 at the SPINvitational held on - 29 Dec 2008. 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.