This page explains how Chuck Chui (USATT# 4880)'s rating went from 1669 to 1642 at the Butterfly San Francisco Open 2015 held on - 15 Mar 2015. 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.