This page explains how Olaf Surmann (USATT# 81607)'s rating went from 2063 to 2061 at the ICC - Advanced League event from 22 May 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.