This page explains how Preston Ha Trun Ha Nguyen (USATT# 29200)'s rating went from 2117 to 2109 at the LATTA Open held on - 30 Aug 2009. 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.