This page explains how Jonathan Chang (USATT# 218218)'s rating went from 1346 to 1306 at the OCTTA BUTTERFLY DECEMBER 2021 OPEN held on 11 Dec 2021 - 11 Dec 2021. 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.