This page explains how Olaf Surmann (USATT# 81607)'s rating went from 2138 to 2133 at the ICC STIGA California Open held on - 6 Dec 2015. 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.