This page explains how Peter Gaidarev (USATT# 92458)'s rating went from 1638 to 1639 at the Boston TTC event from 28 Apr 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.