This page explains how Sasha Parfenov (USATT# 79070)'s rating went from 1687 to 1678 at the 888 League event from 12 Sep 2021. 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.