As promised, here is the follow-up to last week’s post about understanding iron designs. Today, I’m going to tell you what to look for as you try to figure out which iron best suits your type of play and is most likely to deliver the performance you seek. Oh, and these principles apply to wedges as well.

Let me begin with a historical observation.

Up until the introduction of the first mainstream cavity back/perimeter-weighted irons, the entire market was limited to some type of forged blade design. Across the entire spectrum of brands and models, there were only subtle nuanced differences from one to the other. Some featured some kind of “muscle back”, where the mass was concentrated low in the clubhead and the shaping formed a sort of crescent on the back of the club, the majority of mass being in the center of the clubhead (from heel to toe). Others spread that mass more evenly across the back of the clubhead (i.e. the Hogan designs), while others shaped their back to provide a bit more mass toward the toe, as in the traditional Wilson Staff models.

Then the “revolution” came with the Ping Eye 2 and all its copies. These early cavity-back designs moved much of the mass to the extreme perimeter of the clubhead, leaving a thin face, which delivered a high degree of forgiveness of off-center hits, but also deteriorated the consistent distance control delivered by the traditional forged blades. They also launched the ball much higher, making long- and mid-irons much easier to hit, but compromising the traditional precision of shorter irons.

Golfers had to make choice between shotmaking precision and forgiveness of mishits.

This design “revolution” also set in motion the continual strengthening of lofts in the shorter clubs to where we are today when “P-clubs” can be as low as 42 degrees – a far cry from what a true “pitching wedge” must be. See my post on that here. 

The one thing in common with both of these approaches to iron design was that “what you see is what you get.” There were no internal technologies, so a visual examination of the clubhead could tell you pretty much how that iron was going to play.

As iron technologies have advanced, many radical designs have come and gone, but the performance of the traditional blade and the traditional cavity-back remain. Modern technologies allow much more precision in making iron heads, and multi-material construction has given club designers much more freedom to explore and refine performance, but these principles of iron head design are constant. For the most part, the golf ball will react to how a clubhead’s mass is distributed and where its CG is located. Period.

Understand that for each clubhead number or loft, the weight of the clubhead does not vary by more than a few grams from model to model to model. The designers’ challenge is to position that finite amount of mass in such a way as to achieve the performance goals for that particular model. So, here are the parameters designers have to consider, and that you can consider when looking for a new set of irons:

To begin, golf ball performance is determined by how much mass will be directly behind various points of impact on the face. The reason blade designs are still preferred by the best shotmakers is that these designs put mass directly behind the point of impact with the ball, thereby giving the golfer the maximum ability to control distance, trajectory, and shape of the shot.

Conversely, if the area behind the strike zone is thin, the club will likely be “hotter” but distance consistency will be compromised.

If a large portion of the mass is positioned lower in the clubhead, that design will launch higher, and likely with less spin. While this might be desirable in the lower lofts; high launch and low spin are probably not what you want in your higher-lofted scoring clubs, say those over 37-39 degrees, and particularly not with your wedges.

If mass is concentrated in the center of the clubhead from heel to toe, center strikes will be extremely solid and repeatable, but misses toward the toe will be more compromised than a design that has the mass more evenly distributed across the entire clubhead.

If some of the mass is distributed toward the low toe area, that club will be more forgiving of toe mis-hits.
Thin, fast faces and hollow or foam-filled construction is the rage now, but the trade-off is losing some distance precision in exchange for more distance (which comes from higher launch and less spin).

Another modern development is the use of heavy tungsten inserts low in the clubhead, which adds to the higher loft and lower spin distance formula – that might be desirable in the longer irons, but that’s exactly the opposite of what you want in the scoring clubs.

Big wide soles were more the rage a while back than they are now, but the wider the sole, the lower the mass distribution, so the higher the launch angle and the lower the spin. And these super wide sole designs are not very good for tighter turf conditions.

All golf clubhead designs are bound by two distinct principles – gear effect and smash factor.

Gear effect determines the trajectory and spin the golf ball will take. The higher the clubhead mass is distributed (i.e. blade designs), the lower the ball flight and higher the spin rates. Likewise, the more mass that is distributed toward the toe or heel from the strike point, the more likely the ball will curve back to the center.

Smash factor is the efficiency of transfer of clubhead speed to ball speed. Every club has one perfect point of impact that maximizes smash factor and that transfer of energy begins to deteriorate as impact is moved away from that point. That’s why you get occasional “heaters” off most thin-faced irons and see significant distance loss on more traditional blades. It’s also why those high-face misses with traditional wedge designs just pop-up with greatly reduced distance and spin.

I hope this has been enlightening and helpful.

More from the Wedge Guy

• The Wedge Guy: Understanding iron designs, Part 1
• The Wedge Guy: Mind the gap
• Wedge Guy: There’s no logic to iron fitting