This page explains how Kai Zhang (USATT# 86637)'s rating went from 2663 to 2659 at the Westchester 2017 October Open held on 28 Oct 2017 - 29 Oct 2017. 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.