This page explains how Lucas Shao (USATT# 1180878)'s rating went from 591 to 583 at the Butterfly S&S December Open held on 16 Dec 2023 - 17 Dec 2023. 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.