This page explains how Kelvin Koh (USATT# 90486)'s rating went from 2011 to 1978 at the NJTTC Thursday Adv League event from 13 Jul 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.