This page explains how Long Zhu (USATT# 271274)'s rating went from 1389 to 1384 at the 2021 December Open @ Princeton Pong held on 4 Dec 2021 - 5 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.