This page explains how C. Evan Oswald (USATT# 59885)'s rating went from 998 to 991 at the AZ PTTC Monday event from 14 Sep 2015. 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.