This page explains how WILLIAM C. HALL (USATT# 6378)'s rating went from 1869 to 1804 at the AITTA event from 13 Feb 2011. 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.