This page explains how Long Xiao (USATT# 152922)'s rating went from 1679 to 1669 at the SVTTC Sunday U2000 event from 11 Dec 2011. 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.