Cavity vs. Muscle Back Irons

Choosing Iron Types is a Trade-Off of Performance Characteristics

When considering an iron set, these are categorized into two categories of design: blade/tour irons (also called muscle backs) and cavity back or game improvement irons. These two different “types” of irons incorporate different features to accommodate a different playing style or playing capability. Usually, players with low to mid level handicaps and more developed skills can handle the unique qualities of blade irons. The distance control and ball flight is much better for a low handicapper.The name “blades” comes directly from the blade shape of the iron head. On the other hand, “cavity backs” have a hollow cavity behind the club face and are much more suited for high handicap players. Because of their solid design, blade golf irons have an even distribution of weight with a smaller hot spot, hence are also less forgiving than their counterpart.

The fact is that every golfer is not created equal and possesses a different level of playing ability. Cavity back irons are better for higher-handicap golfers, but this is only true because in general no golfer is better off playing a muscle back iron over a cavity back iron unless that person is skilled enough to rarely miss the center of the clubface. Repeated testing has proven that most deep cavity back iron designs will deliver more distance from an off-center hit than will the majority of muscle back irons. This is due to the fact that the cavity back iron has a higher moment of inertia within the vertical axis of its center of gravity.

On the PGA Tour, cavity back irons have crossed the 50% threshold in terms of usage. Professional golfers are split halfway in terms of using the cavity back or muscleback irons. But, the reason many professional players are still using muscleback iron designs is because they are convinced an intentional fade or draw of the ball comes more easily with a muscle back over a cavity back iron. They also state that the “feel” of impact when hitting a muscle back iron is “softer” or simply more pleasing compared to a cavity back, which increases their confidence.

Cavity back irons offer a larger hot spot, which makes contact will the ball easier and subsequently will “correct” slightly mis-aligned shots. This is called “forgiveness” and it is what these clubs are known to do. They actually make it easier for you to hit the ball straighter and with distance more consistently. For the majority of casual golfers – this is defining decision to choose cavity back irons. Conversely, blade irons provide a much truer reflection of a golfer’s actual swing on any one shot. This means that if the club face is slightly mis-aligned on impact the mis-alignment will be immediately apparent in the trajectory, distance, and direction of the golf ball after contact. So, blades will provide more feedback during a shot. Muscle back blades do tend to be smaller than cavity backs. Also, cavity back irons have a hollow, lighter feel on impact. Blades are about feel and definitely reward a good ball strike than cavity back irons.

While cavity backs are much easier to play for the average golfer, they do not necessarily enable a person to hit the ball straighter and further with more consistency. While cavity backs will result in a quicker level of consistency, they do possess two major flaws. First, they are swing corrective by design, thus faults in a golfer’s swing can be easily hidden. Your game improvement can often plateau more quickly with cavity backs. Often when players make the decision for switching to blades later on when a plateau is reached – their game regresses as swing faults that were once hidden become instantly magnified and scores increase. This is the main reason that blades get negative reviews. Second, with the short game, cavity back irons generally lack the critical feel in approach to the green and lessen shot-making capabilities. In other words, the over-sized improvement iron club heads make control more difficult especially with the shorter irons.

Another point you may want to consider is alignment at address. Ironically, many people find it much easier to align the thin top line of muscle back irons over the thicker top line of the cavity backs. This is a simply visual perspective. It still does not enable the blades to be easier to hit. But again, top pros are using cavity backs successfully and keep in mind these are tour golfers that practice more than anyone else. Apparently, visual perspective as well as the lack of feedback does not appear to be hurting some of the best players in the world.

If you are a novice at golf and just learning the game or if your objective is to simply play for enjoyment – a cavity back set is the way to go. Cavity back irons will also help to build confidence with the long irons in particular. However, if your goal is to perfect your swing and control the ball with the short irons or to play competitively – a set of precision blades are the better choice. To most golfers, it is almost impossible to hit blades, but that may not be true for you. Blades force the player to work hard and hit a shot as cleanly and purely as possible. What you gain by using a true blade set is a much more solid feel of impact, more consistent distances on good shots, and increased ability to work the ball flight – both vertically & horizontally on knockdown shots, draws and fades.

One idea is to practice at the range with a set of muscle back irons and then use your cavity backs on the actual course. It certainly should improve your swing and make you more disciplined with the cavity backs after a little work with the blades. Hitting anything above a 5 iron requires a precise and repeatable swing. With practice, blades can by default, make your overall game better. Since blades have been around decades longer, it is quite easy to find a decent inexpensive set on Ebay or at a garage sale. However, if you are content with with your game and just like to get out and play, save yourself the possible frustration of blades.

NOTE: Try not to judge blades by the old set in your dad’s or grandfather’s garage. The modern blades are much easier to hit than the old designs, but still not nearly as easy to become proficient at like cavity backs. The weight distribution and sole design have greatly improved. If looking for a used set of muscle backs, remember that many of the old blades have a very long hosel, therefore a center of mass that is not in the center of the club face, but more toward the hosel. The more modern shorter hosel designs are easier to hit center. Hitting off-center shots on blades can be devastating as they are far less forgiving. Additionally, most of the older blades also had negative bounce in the sole, which makes them very difficult to get back up and out of the turf.

Of course, a player’s ultimate success largely depends upon their personality and how they learn. The level of tolerance and subtlety in relation to muscle memory is different for each person. What is optimal feedback to some will be different for other people. Some golfers need a lot of feedback, whereby others can shoot fine without much. It is ultimately a personal choice. There are inherent advantages and disadvantages for both cavity back and muscle back irons. Finding the right type for yourself may be a matter of trial and error. As long as you are aware of the differences, it makes the choice less complicated.