This page explains how Luis Mejia (USATT# 222018)'s rating went from 1209 to 1248 at the 2018 US Open held on 16 Dec 2018 - 22 Dec 2018. 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.