This page explains how Andrei Ilnitskii (USATT# 216594)'s rating went from 1559 to 1546 at the 2023 SPTTC October Open & Washington Championships held on 21 Oct 2023 - 22 Oct 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.