This page explains how Barbara Clark (USATT# 89272)'s rating went from 1463 to 1354 at the 2018 ICC Butterfly America Open held on 7 Dec 2018 - 9 Dec 2018. 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.