Ever heard about Maltby Playability Factor??? in General Q&A Posted July 30, 2021 The Maltby Playability Factor (MPF) was developed by Ralph Maltby as a way to evaluate and differentiate the playability of iron designs. Located at: https://www.golfworks.com/iron-head-mpf-ratings/a/870/ Iron heads are rated from ultra game improvement to player classic. All manufacturers, all versions. Anyone have an opinion on how accurate or helpful the ratings??