This page explains how Andrzej Cholowicz (USATT# 78049)'s rating went from 1621 to 1613 at the Summer Open held on - 30 Jul 2011. 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.