This page explains how Marco J. Borrillo (USATT# 59455)'s rating went from 1639 to 1638 at the TT&M Friday Night Butterfly League event from 1 Sep 2023. 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.