This page explains how Kelvin Koh (USATT# 90486)'s rating went from 2026 to 1981 at the NJTTC Monday League event from 18 Nov 2019. 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.