This page explains how Helen Wilson (USATT# 10989)'s rating went from 1213 to 1211 at the Trolley Car TTC Tuesday Night League event from 3 Dec 2013. 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.