This page explains how Henrik Zhang (USATT# 87832)'s rating went from 1820 to 1817 at the SVTTC Sunday U2000 event from 20 Sep 2015. 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.