This page explains how Vladimir Zafrin (USATT# 279587)'s rating went from 516 to 509 at the AZ PTTC Monday event from 18 Sep 2023. 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.