If you have two different paddles with the exact same weight one paddle may feel heavier in your hand than the other. Why? The answer is that there is a difference between a paddle’s static-weight (often called just the “weight”) and its swing-weight. Although the static-weights of the paddles are identical, the swing-weight of one paddle is greater than that of the other. The paddle’s swing-weight is simply how heavy the paddle feels in your hand when you swing it, and it is dependent on both the total weight of the paddle and how the weight is distributed on the paddle. This article introduces the idea of swing-weight and describes why a paddle’s swing-weight must be matched to a player’s ability.
What is the Paddle Swing-Weight?
Swing-weight is a term that is used often in golf and tennis but is less commonly used in pickleball. If you do an Internet search on swing-weight, you will find several confusing explanations. In golf, the swing-weight of a golf club is determined by the weight of the bottom two-thirds of a golf club. In tennis, the swing weight is determined by a Racquet Diagnostic Centre (RDC) which is a machine that can be found in good tennis pro shops that assigns the racquet an RDC number that corresponds to its swing weight.
In truth, the swing-weight of a golf club, tennis racquet, or pickleball paddle is simply the mass moment of inertia (or MOI) of the paddle about the pitch axis, which we discussed and calculated in our article, “Where is the Sweet Spot?” So, let’s delve a little deeper into why the swing-weight is important, and why pickleball paddle manufacturers should include swing-weight in their paddle specifications.
Why is Swing-Weight Important?
As we explained in our article, “Why is the Sweet Spot is Important?”, the weight of the paddle and the force exerted by the ball striking your paddle is reacted about a pivot point that is located at the center of your palm. Your wrist must supply a torque to counterbalance the weight of the paddle acting through the paddle center of gravity (cg), or the force of the ball striking the paddle at some distance from the pivot point (i.e., torque equals force times distance).
Newton’s Third Law of Motion states that a body in motion tends to stay in motion and a body at rest tends to stay at rest unless acted upon by an external force. As you hold or swing your pickleball paddle, the mass properties of the paddle itself will assist you in counterbalancing the force of the ball striking the paddle. That is,
T = Iα
Where T is the torque, I is the mass moment of inertia (MOI) and α is the angular acceleration of the paddle. Therefore, for a given level of angular acceleration (α) a paddle with a larger MOI will be more resistant to an external force or torque (such as a pickleball striking the paddle) than a paddle with a smaller MOI.
Advantages and Disadvantages
So why wouldn’t you just get a paddle with a large MOI? On one hand, a paddle with a large MOI will have greater stability. That is, when striking a ball, the paddle will tend to “plow through” the ball without requiring a significant amount of correcting torque from your wrist. On the other hand, a paddle with a large MOI will generally be heavier and require greater strength to swing the paddle, which may result in slower reaction times, slower swing speed and lower ball velocity. (We will discuss the relationship between ball velocity and swing speed in a different article.) Furthermore, a paddle with a large MOI may be difficult to maneuver, as your wrist will need to supply a larger amount of torque to turn the paddle. This may be especially important for shots at the net, such as volleys, where you may need to rapidly rotate your paddle from forehand to backhand shots.
The advantage of a lighter paddle with a lower MOI is that it will be easier to swing, which could potentially increase your swing speed and reduce your reaction time when maneuvering your racquet. However, the smaller MOI will make your paddle prone to rotation when the ball strikes the paddle, which could result in mis-hits. This would be especially true for balls that approach you at high velocities, causing your wrist and paddle to rotate depending on where the ball strikes the paddle face. A greater amount of wrist strength and control may therefore be required when using a paddle with a smaller MOI. Pickleball players may need to slow down their swing speed to reduce the reaction force from the ball when they initially switch to a lower MOI paddle. When they learn to reliably contact the ball at the sweet spot and better control their paddle through their swing they can increase their swing speed to create higher velocity shots.
How Do You Select a Paddle?
From the above, it should be evident that there is no “one-size-fits-all” paddle regarding its MOI. A player with good arm strength and quick reflexes (such as Ben Johns) may benefit from a heavier paddle with a larger MOI. However, an amateur player who may not have the arm strength or reflexes of Ben Johns may be better suited to a lighter paddle with a lower MOI. Therefore, just because your favorite pro uses a certain paddle will not guarantee your success when using it. Pickleball players must therefore match the weight and MOI of their paddles to their abilities.
One of the problems in selecting an appropriate pickleball paddle based on swing-weight is that manufacturers describe their paddles in terms of static-weight only. While static-weight is important, the distribution of the weight along the length of the paddle determines the swing-weight of a paddle. The swing-weight is affected by several factors that are not obvious based on appearance. For example, a lighter elongated paddle (Figure 1) may have a larger swing-weight than a heavier standard paddle. If the weight is biased towards the top of the paddle (head-heavy), it will have a greater swing-weight than a paddle with the weight biased towards the handle (head-light).
Pickleball players must therefore experience playing with a new paddle before determining if it has the right combination of static- and swing-weight that suits their style of play and abilities. On one hand, a player might find that when using a head-heavy paddle, the velocity of their shots has decreased, or that their reaction times at the net seem slower. On the other hand, a player may find that when using a head-light paddle, it may seem difficult to control the direction or placement of their shots.
To make it easier for pickleball players to select an appropriate paddle, pickleball paddle manufacturers should list the swing-weight of their paddles along with the static-weight. Of course, standards will need to be developed so that the swing-weight of different paddles can be compared on an apples-to-apples basis. The swing-weight could be determined either experimentally or analytically.
What's Next?
In “Paddle Selection: Swing Weight” we measured the swing-weights and sweet spots of several paddles to give you an idea of the range of swing-weights available, and to help you select an appropriate paddle. We will further discuss how a pickleball player can change the paddle’s swing-weight, the cg location, and the sweet spot by using weighted (lead) tape on the edges of their paddle faces or by using an overgrip on the paddle’s handle.
