This page explains how Birgit Eisenkoelbl (USATT# 223145)'s rating went from 546 to 457 at the HITTA Weekly League event from 15 Oct 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.