MyGolfSpy Labs: The Driver Fitting Study

The driver is typically one of the most fitted and often replaced clubs, and is usually the most-expensive club in one’s bag.  A properly fit driver can have a dramatic effect on distance, accuracy, consistency and confidence; maximizing the opportunity for optimal results. When looking at driver fitting many principles from an iron fitting carry over, but there are some unique aspects to the driver (e.g. some elements of adjustability).

The goal of this article is to prepare players for their next driver fitting by discussing what to look for during a fitting, which elements may be altered during the process, and demonstrate the benefits of a thorough driver fitting.

Things to Look for During a Driver Fitting

As mentioned above, driver fittings and iron fittings share similar aspects. Please reference the iron-fitting article for a more in-depth description of the following items that a golfer should pay attention to during a fitting:

• Conversation/Interview
• Bring current driver for comparison
• Pay attention to what is added to the club during the fitting
• Put a priority on ball speed instead of smash factor
• Pay attention to which fitting elements are addressed

In addition to the above items, a few critical aspects of a driver fitting merit more discussion.

Ball flight

Most fitting environments have a way to track and record ball flight using a launch monitor, an easy and objective tool for ensuring a golfer is getting the most from a driver. Compared to other clubs, the distance a shot travels with a driver is particularly sensitive to spin rate, since the driver produces the highest ball speeds. The higher the ball speed, the greater the aerodynamic forces experienced by the golf ball. This can lead to excessive lift, or insufficient lift, which can significantly reduce distance. This phenomenon is depicted in the image below.

To expand on this, there are optimal combinations of launch angle and spin rate that tend to generate the greatest distances, combinations that are a function of the ball speed a player generates. Figures 2-4 show the carry distances that various combinations of launch angle and spin rate can produce for ball speeds of 100, 140, and 180 mph, respectively. Studying these figures, it is clear that for a given spin rate, carry distance increases with launch angle. Conversely, for a given launch angle you can see that minimizing spin rate may not always result in the greatest carry distances. For high-ball-speed players, minimizing spin rate can definitely lead to greater distances, but for slower to average-ball-speed players, a slightly high spin rate may ultimately lead to more carry distance off the tee.

It should also be noted that for now we are exclusively speaking in terms of carry distance. When discussing what happens to total distance, the landing angle and typical fairway conditions can also significantly affect the amount of total distance one gains, and sometimes needs slightly lower launch/spin combinations are required to maximize total distance. These tables are also generated for a set environment (i.e. temperature, elevation, etc.), which can also change the contours by a fair amount.

Groups of Shots (instead of single shots)

Particularly with a driver fitting, golfers are inclined to be drawn to the model that produced that single “bomb” that felt better than you could’ve ever imagined and sailed 15 yards farther than anything you’ve ever hit. Although this may give an indication of what the perfect shot with a given club feels like, it may not be a good representation of the performance you would see on the course. One of the defining characteristics that trends with handicap is consistency. Generally, the lower a player’s handicap, the more consistent they are shot-to-shot. So in addition to those single shots, pay attention to groups of shots. More times than not, a fitting focuses too much on comparing the BEST shot with one driver to the BEST shot with another. This is incomplete, at best, and in many cases will add strokes to your game rather than eliminate them.

The table below compares two of the best single drives during a fitting for two different drivers. You can see that driver B had a greater total distance and optimal launch conditions, compared to driver A. Of course, the 300-plus-yard drive is enticing and is going to stay at the front of the player’s mind. That is 8 yards more than he generated with club A, so surely this is the best driver for him, right?

Although this is part of the story, it is quite a disservice to the performance of driver A. The two images below compare the eight drives with each driver during the fitting with the same two models shown in table 1. The shots are overlaid on a par 4 with a density heat map overlay at Mesa Country Club, a local course in Arizona. Looking at the data presented in this way tells a completely different story! Not only is the variance in distance much larger, driver B will have you dodging range balls on your second shot 30% of the time.

Evaluate the best shots with the different drivers you try, but analyzing the grouping of shots with each is crucial to assessing the true performance of a configured driver.

Tee Height

Tee height is important to optimizing trajectory and distance with the driver. When teed too low, the ball typically launches lower with excessive spin. When teed too high, the ball may impact high on the face, leading to a higher launch angle than desired with insufficient spin. Hitting too high or low can also significantly affect ball speed. Typically, an average tee height that places the equator of the ball even with the top edge of the driver face works best for most. Particularly in an indoor environment, it is important to ensure that one can adjust tee height and achieve a sufficient tee height during a fitting. If you are not comfortable with the tee height during the fitting, be sure to discuss this with your fitter.

Fitting Elements

A number of factors can influence distance, control and feel with a driver – performance characteristics that should be optimized during a fitting. Most fittings should address the majority of the following elements during a fitting.

Model

The center-of-mass (COM) of a driver can play a huge role in the performance characteristics of a driver. Specifically, driver models with different COM locations will have different launch and spin characteristics, which may lead to optimal ball flight for a particular player. In addition to launch characteristics, the COM location also has significant effect on the moment-of-inertia (MOI), or the forgiveness one experiences. In general, as the COM is moved farther away from the face of a driver, the higher the MOI and the launch angle, and as it is moved lower, the less spin a head will generate. Moving the COM to the heel or toe side of a driver can also have an effect on left-right trajectory. On drivers that have movable weights, a fitter may try to move weight toward the toe or heel to correct a miss tendency to the left or right. For the most part, moving the COM to the heel will generate a more right-to-left ball flight, while moving weight to the toe will lead to a more left-to-right shot shape.

Other aspects that can also influence the performance and feel of a model are the look and sound characteristics of the head. The preference of these variables is highly dependent on the player, but they can definitely lead to increased confidence and improved feel.

Loft

Loft is the angle of the clubface relative to a vertical line perpendicular to the ground. Loft has considerable influence on the launch angle and spin rate of a golf ball, although other factors such as shaft type and model also influence launch conditions. PING drivers are offered with different lofts to fit players of varying swing speeds, swing tendencies and ball-flight preferences.

Many PING metal woods, as well as many heads from other OEMs, provide the ability to adjust the loft, allowing players to fine-tune their ball flight and trajectory. PING research has shown that in general, a 1-degree increase in loft for a driver will result in a 0.7-degree increase in launch angle and a 220 rpm increase in spin rate. This relationship can be used to guide the use of adjustable loft when tuning trajectory during a fitting where launch-monitor data is available. During a fitting, the loft of the head as well as the adjustable loft setting of that head serve as important levers when dialing in ball flight.

Length

Altering the length of a driver can have a significant effect on performance. As length is evaluated, keep in mind the trade-offs in performance that can govern changes in driver length. Table 2 displays how altering length while maintaining a constant swingweight can affect performance. For example, for a 1-inch increase in length, the carry distance increases an average of 4 yards. As a general rule, an increase in length can increase distance, but will usually lead to a significant decrease in accuracy. There is also a point with most players where increasing length will lead to shorter distances due to poorer contact, though this point is highly dependent on the player.

The driver lengths used on the men’s and women’s professional tours are worth noting. For PING pros on the PGA and European tours, driver lengths range from 44.25″ to 46″, with an average of 45.25″. On the LPGA Tour, lengths range from 44.5″ to 48″, with an average of 45.25″.

Shaft

Players have a vast array of choices when it comes to shaft fitting. Various combinations of weight, flex, and torque can affect the way a shaft feels and performs. Ultimately these shaft properties can not only have a big effect on how a driver feels as it is swung and as it impacts the ball, but also can influence the trajectory that can be achieved with a given model.

Typically, fitters will base an initial driver shaft recommendation on a player’s swing speed and distance. In general, club head speed would be the best INITIAL indicator since distance can be greatly influenced by player perception and quality of contact. Although other factors (tempo, transition, impact position, etc.) may influence shaft recommendations, club head speed is a decent starting point. As you try different shafts, the fitter should solicit feedback about feel (flex, weight, impact) and performance, and evaluate how each shaft affects ball flight.

During this process of elimination, golfers should resist the urge to look at the shaft flex code (R, X, S, etc.).  Unfortunately, there are no true industry standards regarding these labels. As a result, some shafts labeled Regular are in reality quite stiff, and shafts labelled X-Stiff are quite flexible. This was mentioned in the previous article on iron fitting, but it’s a point worth repeating. PING characterizes each shaft that it offers, measuring a playable flex. Comparing shafts on a chart like the one in figure 10, it is clear there is plenty of overlap between shafts labeled with a particular flex code. As a result, it is best to not know during the shaft fitting what you are hitting so that you don’t influence your perception of the results.

Grip

Similar to irons, testing has shown that grip size can have a small influence on ball flight and the confidence a player has as they swing the club. Grips are available in a wide range of sizes, and grip-fitting charts like the PING Grip Chart provide a starting point for the fitting and offer high statistical probability of an optimal size recommendation based on measurements of the hand and fingers. Try a couple of grip sizes to determine differences in performance or feel.

Weight & Balance

The ultimate weight and balance of a driver can be influenced by the model, shaft, and grip, elements a fitter can modify to help optimize performance. If you prefer a certain feel and weight, let your fitter know. Two of the primary ways the mass properties of a driver are characterized is by total mass and swing weight. For a more in-depth description of these two variables, please see the Weight & Balance section of the iron-fitting article.

As with irons, overall swingweight can affect performance by influencing the way a club is delivered. In general, heavier swingweights and total weights tend to fight a miss to the left, while lighter clubs tend to fight a miss to the right. Most equipment manufacturers have dialed in swingweights for their drivers that provide the best performance for the overall population, but weight and balance should be part of the fitting discussion.

Performance Gains

So the big question is, how much improvement can I expect from a driver fitting? PING’s nFlight software is used by accounts around the world and gives us a great window into the performance gains that can be had through a proper driver fitting. A large sample of fittings conducted at PING over the past year shows that players averaged an increase in total driver distance of around 11 yards, and averaged 9.5 extra yards carry, with an optimally fit driver compared to the gamer they were using when they came into the fitting. As you can see from the charts, most all players gained distance, with a few exceptions where control and accuracy were a high priority.

Table 3 shows how the driver that was fit to a player varied in launch conditions to their gamer. Over the sample group, players gained a couple of miles-per-hour in ball speed, a higher launch angle, and a lower spin rate. These are averages across a sample of players, so certain individuals may have lowered their launch angle or increased spin in order to optimize ball flight.

As discussed earlier, the other critical elements in a driver fitting are dispersion and consistency; both typically improve significantly after a thorough driver fitting. Most launch monitor and fitting software includes a method for visualizing groups of shots with a particular club. Over the same sample of fittings, the dispersion area decreased by 25% on average when comparing the fitted driver to the player’s original driver.

To provide a baseline for what a 25% reduction in dispersion area looks like, the representative average stat areas for the sample of players for both their fitted driver and their gamer have been overlaid on the 18^th hole at Torrey Pines South in figure 13. Although at first glance this visual may not serve as a striking argument to pay attention to dispersion, keep in mind this is an average across the entire sample of players, and within that sample there are examples like the one presented in figure 7 where the differences are substantial. A few less shots out of a fairway bunker or the penal rough can definitely serve to lower scores over the course of a round.  That combined with the extra distance, which on average will allow a player to hit one less club into a green, will ensure lower scores as a result of a driver fitting.

There are clearly gains to be made in ball speed, distance, accuracy and feel through a proper driver fitting. If you’re planning to get fit for your next driver, go in with a working knowledge of what to look for during a fitting to ensure that you get the most out of the experience.