This page explains how Derrick Cone (USATT# 64672)'s rating went from 1899 to 1890 at the Tucson Table Tennis Club League event from 26 Oct 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.