This page explains how Sean Koster (USATT# 212045)'s rating went from 1567 to 1553 at the 2017 Arizona Closed held on 29 Apr 2017 - 30 Apr 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.