This page explains how Alhasan Mohamed (USATT# 219890)'s rating went from 1415 to 1409 at the Westchester January 2020 Open held on 25 Jan 2020 - 26 Jan 2020. 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.