This page explains how Jianglin Mei (USATT# 21811)'s rating went from 1927 to 1921 at the Westchester 2012 September Open held on - 30 Sep 2012. 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.