This page explains how Zhaoqun Zhou (USATT# 4287)'s rating went from 2064 to 2050 at the Topspin Advanced League event from 1 Dec 2018. 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.