This page explains how Sarah Shuangxia Zhu (USATT# 268233)'s rating went from 411 to 399 at the WCTTA Saturday League event from 17 Mar 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.