This page explains how Jeffrey Xun Zeng (USATT# 74600)'s rating went from 2559 to 2556 at the MDTTC Butterfly October Open held on 14 Oct 2017 - 15 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.