This page explains how Keenan Zhou (USATT# 95558)'s rating went from 1966 to 1949 at the San Diego Open 10K Tournament held on 12 May 2018 - 13 May 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.