This page explains how Jonathan Gehrkin (USATT# 91627)'s rating went from 1257 to 1243 at the 2017 Butterfly WDCTT Spet Open & DC Closed held on 23 Sep 2017 - 24 Sep 2017. 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.