This page explains how Felix Shtorper (USATT# 15550)'s rating went from 1837 to 1809 at the TT&M Friday Night Butterfly League event from 19 May 2017. 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.