Ralph has developed an analytical system to understand how iron club designs play. In this book, he explains how several mass and dimensional properties of an iron head determine how the clubhead behaves when striking the ball. He then takes those properties, measures them and puts them through a calculation that results in an index of playability. He discusses the theory behind iron design and translates into a practical guide for understanding iron playability and even a guide for iron designers. Finally, the book includes the results of measuring most of the modern irons available today.