This page explains how Allan Beihao Cheng (USATT# 217555)'s rating went from 1261 to 1256 at the SJISC Butterfly December Open held on 18 Dec 2021 - 19 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.