This page explains how Alistair A Hay (USATT# 91523)'s rating went from 887 to 870 at the NYITTC October 2015 Open held on - 4 Oct 2015. 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.