This page explains how Sam Lawton (USATT# 92490)'s rating went from 1972 to 1989 at the 2022 Butterfly May Upside Down Tournament held on 21 May 2022 - 22 May 2022. 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.