This page explains how Mike Burg (USATT# 219356)'s rating went from 1800 to 1771 at the TT&M Friday Night Butterfly League event from 20 Sep 2019. 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.