This page explains how Walter Witkowski (USATT# 21983)'s rating went from 1167 to 1059 at the ICC CA State Open held on - 19 May 2013. 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.