This page explains how Chenguang Zhu (USATT# 91100)'s rating went from 2015 to 1977 at the Spttc Saturday Night League event from 21 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.