This page explains how Mark Nordby (USATT# 8741)'s rating went from 1958 to 1964 at the Grand Rapids TTC September Ope held on - 30 Sep 1995. 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.