This page explains how Joel Sommer (USATT# 96857)'s rating went from 1666 to 1606 at the PPC December Open held on 9 Dec 2017 - 10 Dec 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.