What is MOI matching?
Every club has an MOI (Moment of Inertia), which (in greatly simplified but helpful terms) measures its resistance to being swung. An off the rack set of irons matched for swingweight would have as many different MOIs as there are clubs! In a set of irons having the same MOI, however, all irons would feel the same to you. Is this a good thing? Every clubmaker I know (and know of) reports that using MOI fitting produces clubs that feel the same, and, more importantly, result in a minor to significant increase in the percentage of solid, on-center hits. A golfer “waggling” a club before swinging may notice a progressively increasing head weight feel as the clubs get shorter in an MOI matched set, but as soon as the clubs are swung full, golfers report that they can close their eyes, switch clubs in the set, and not really detect any difference in the total swing feel of any of their MOI matched clubs.