This page explains how Willa Tammy Gu (USATT# 30325)'s rating went from 1858 to 1894 at the 2009 San Diego Open held on - 26 Apr 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.