This page explains how Sergey Tsvor (USATT# 25053)'s rating went from 1975 to 1955 at the First Slavic event from 8 Jul 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.