This page explains how Sung Park (USATT# 264900)'s rating went from 400 to 390 at the Pong Planet Friday Night, Tuesday Night, And Saturday Leagues event from 17 Aug 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.