This page explains how Allen Xiao (USATT# 270881)'s rating went from 251 to 192 at the ICC - Sunday Beginners League event from 21 May 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.