This page explains how Thelma Tybie Sommer (USATT# 10155)'s rating went from 1398 to 1373 at the US Nationals held on - 18 Dec 1994. 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.