This page explains how Nelson Yamada (USATT# 269784)'s rating went from 1289 to 1284 at the AZ PTTC Monday event from 13 Sep 2021. 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.