This page explains how David Contraras Guevara (USATT# 28139)'s rating went from 1500 to 1498 at the Boston TTC event from 7 Jul 2015. 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.