This page explains how Barbara Clark (USATT# 89272)'s rating went from 1253 to 1222 at the ICC Butterfly California State Open held on 2 Dec 2016 - 4 Dec 2016. 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.