This page explains how John P. Pratt (USATT# 9196)'s rating went from 1430 to 1415 at the Utah Valley Open held on - 19 Apr 2008. 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.