This page explains how Reid Greenspan (USATT# 18298)'s rating went from 1987 to 1939 at the TT&M Friday Night Butterfly League event from 12 Nov 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.