This page explains how Songling Ngo (USATT# 219645)'s rating went from 457 to 455 at the Spttc Saturday Night League event from 25 Nov 2017. 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.