This page explains how Jim A. Engstrom (USATT# 70172)'s rating went from 1553 to 1571 at the WMITT event from 30 Jan 2020. 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.