This page explains how Carlos Zeller (USATT# 65087)'s rating went from 1504 to 1491 at the Butterfly 2023 February BTTC held on 10 Feb 2023 - 12 Feb 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.