Bringing you insights from the PING Proving Grounds, where our talented team of engineers, researchers, fitting experts and data scientists design and develop the newest product and fitting technologies to help you play better. Using the most advanced tools available, we’ll explain and explore the science behind golf-equipment performance. We’ll separate fact from fiction with the goal of helping you make informed decisions when choosing the PING equipment best suited for maximizing your performance.
Growing up playing junior golf, I was told that a larger grip size would be difficult to rotate and likely lead to a fade, and a smaller grip would promote an early release, resulting in a draw. In “Common Sense Clubfitting,” author and golf professional Tom Wishon echoes these sentiments: “For some golfers a grip that is too large can make it more difficult to rotate the face, [while] too small can enhance the action of rotating the club… but this does not happen with all golfers.” However, his concluding message is that “grips are installed to different sizes strictly so golfers can obtain more comfort.”
At the PING Proving Grounds, we ran a two-part test to understand the effect of grip size on driver performance. In the first test, we built three different grip size drivers as they would be built in standard production. In this case, it meant keeping the swing weight constant for three drastically different color-coded grip sizes: Blue (-1/16”), White (Std.) and Orange (+1/16”).
Swing weight is the torque produced by the club from a pivot point 14 inches away from the butt end of the club. Swing weight is meant to approximate how heavy the club feels during the swing, hence “swing weight”.
By this definition, a heavier grip would counteract the weight of the club head and decrease the swing weight, while a lighter grip provides less of a counterbalance and increases the swing weight. Therefore, in order to keep swing weight consistent across the three different grip sizes, a heavier grip must be paired with a heavier head. Similarly, a lighter grip will be paired with a lighter head. As a result, the total weight of the three clubs will be lightest for the smallest grip and heaviest for the largest grip.
Moment of Inertia (MOI) is another measurement of how heavy the club will feel during the swing. MOI is calculated by taking the sum of each point of mass and multiplying by the distance from the butt end of the club squared.
For the oversize grip, the combination of a heavier grip paired with the heavier club head increased the club MOI relative to the smallest grip condition. Therefore, although we are controlling swing weight, it is important to note that total club weight and MOI are not held constant, which foreshadows why this turned into a two-part test.
We asked 18 golfers to hit 8 shots with each of the three different grip size clubs with the same swing weight. Each shot was captured using our state-of-the-art ENSO motion-capture room.
So, what did we find?
Looking at the graphs above, on average the largest grip was delivered almost 2° more open than the smallest grip. This led to a massive 8-yard difference in offline distance. The lack of overlap between the error bars, when comparing smallest to largest grip clubs, means the results are statistically significant. The p-value means that there is a less than 0.1% chance that you would see such extreme results if the clubs were actually the same. In other words, our test provides very strong evidence that the different grip size clubs led to differences in performance.
This test appears to confirm conventional wisdom; larger grips are more challenging to turn over and lead to more right-side misses (for a RH player) relative to smaller grips. However, although swing weight was kept constant, the total weight and club MOI were altered along with the grip size. After reviewing our findings, we asked ourselves, did the weight or grip size differences cause the change in performance?
In the second test, we wanted to keep all variables constant except for grip size. Assume the heaviest grip is our starting condition. In order to achieve a reasonable swing weight, it needs to be paired with a heavy head like before. Now for the other two conditions, we want to keep the mass properties as constant as possible, so we use the same heavy head and shaft. The smallest grip does weigh less than the largest grip, so we make up for this difference in weight by inserting a plug into the shaft located near the center of gravity of the grip. As a result, swing weight, total mass and club MOI are now almost perfectly controlled.
For our second test, we once again had 18 golfers hit eight shots with each club. We are now completely isolating the effect of grip size:
This time we found no significant differences in club delivery or to the resulting ball-flight. The average face angles relative to path were all within 0.3° and the average offline values were all within 3 yards of each other. Furthermore, there were no significant differences by player, while in the first test, nearly half the golfers showed statistically significant differences in either face angle relative to path or offline behavior.
From the first test, we learned that changing grip size can lead to significant changes in club delivery. For example, if you request an oversize grip at the end of a fitting, common practice will be to increase club head weight to maintain consistent swing weight. This will likely result in a more fade-biased shot than you experienced in your fitting.
However, the second test showed that changing the total weight and club MOI were the primary sources of the change in club delivery, not the grip size.
The recommendation for someone who wants a larger grip but prefers the left-right bias with a standard grip, would be to maintain the same head weight as with the standard grip. This will result in a lighter swing weight and slightly heavier total weight but in theory will have a limited effect on left-right bias.
There is still more work to be done to fully understand the effect of grip size on performance. Do certain hand sizes or club delivery methods benefit from specific grip sizes? Should larger grips just simply be fit to people with larger hands? These are some of the questions that we look forward to researching at the PING Proving Grounds.
1. Common Sense Clubfitting: The Wishon Method (2008) Tom W. Wishon
Chris earned a Bachelor of Arts degree in mathematics from Cornell University in 2017. Chris researches club-ball impact and ball-flight physics, and helps develop new tools to analyze PING performance data.