This page explains how Marcos Monzon (USATT# 8580)'s rating went from 1649 to 1621 at the LYTTC Friday Pro League event from 22 Dec 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.