This page explains how Joe Pierotti (USATT# 16090)'s rating went from 1671 to 1616 at the 2023 TT&M's Butterfly Spooky Open held on 3 Nov 2023 - 5 Nov 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.