This page explains how C. Evan Oswald (USATT# 59885)'s rating went from 1271 to 1231 at the Lake Havasu held on - 21 Sep 1997. 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.