This page explains how Ilya Koshkin (USATT# 14637)'s rating went from 1751 to 1728 at the California State Open held on - 31 May 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.