This page explains how Hanson Qin (USATT# 81606)'s rating went from 549 to 551 at the ICC - Entry Level League event from 15 Mar 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.