This page explains how Antonio Mattos (USATT# 1892)'s rating went from 1680 to 1678 at the 2006 Western Open held on - 19 Feb 2006. 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.