This page explains how Mark Johnson (USATT# 26863)'s rating went from 1630 to 1578 at the SVTTC Sunday U2000 event from 28 Sep 2014. 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.