Grip Strength, Impact Location and Ball Speed
How Hard Should You Grip the Handle?
Where on the Face Should the Ball Impact?
3/29/26
Imagine standing at the kitchen line. Your opponent hits a 60 mph rocket toward you. You want to block the shot back with a high velocity if the opponent is close or drop the shot just over the net with a low velocity if the opponent is back at the baseline. What grip strength provides the highest and lowest rebound speed? Where on the face should the impact location be for the highest and lowest rebound speed?
To explore grip strength and impact location an air cannon was used to shoot a 60 mph ball at an Flik F3 elongated paddle outfitted with 4 different clamps to mimic 4 different grip strengths. The rebounding ball velocity was recorded.
Light Grip
A lightweight aluminum ring clamp (SW <1) was used to mimic a light grip. The paddle rotates around a point 2" from the butt and cannot translate.
Heavy Grip
A massive square steel tube weighing 2 pounds ( 4 times the weight of the paddle; SW=56) was used to mimic a strong grip on the handle. The steel tube approximates the weight of a hand. The paddle rotates around a point 2" from the butt, but cannot translate.
Massive Grip
The paddle was clamped rigidly to a concrete block. The paddle cannot rotate or translate.
No Grip
The paddle was hung using a lightweight latex exercise band and mimics the player releasing the grip just before impact. The paddle twists, rotates and translates freely.
Expectations
My expectation was that the paddle clamped to the concrete block would produce the highest rebound velocities at all impact locations. All the initial momentum from the incoming ball has to be divided between paddle movement and the rebounding ball. Since there is no translation or rotation of the paddle, the rebound speed should be the highest of all 4 clamping methods.
Next in line would be the paddle with the massive steel tube. Some of the initial momentum from the incoming ball would be transferred to the rotating paddle, and the ball speed would be a bit less.
The paddle with the lightweight aluminum clamp would be produce less ball speed. The inertia of the paddle/lightweight clamp combination is less meaning more of the momentum is lost to paddle rotation and less is available for ball speed.
The lowest rebound velocity would be expected from the paddle suspended by a rubber band. The paddle is free to rotate and translate meaning more of the initial momentum is diverted to the paddle and less is available for ball speed.
Results
Surprisingly, the rebound velocities of all four "grips" are the same for impact locations below about 5.5 inches. This is confirmation that the ball, at locations near the "sweet spot", doesn't care what's going on at the handle and doesn't care how tightly the paddle is gripped or how much weight is added due to the clamp. The handle is in a different "country" than the ball and has no effect on what's happening at impact locations below 5.5 inches. The ball has rebounded off the paddle face before the shock wave has had time to reach the handle and reflect back to the impact location and affect the ball's speed.
The story is different for impact locations nearer the handle. The distance between the impact location and the handle is shorter meaning the shock wave has had time to rebound off the handle; return back to the impact location; and affect the ball's rebound velocity. At these impact locations the grip can affect the ball's rebound velocity.
For a detailed technical explanation along with practical examples see:
The Physics of the Role of Racquet Mass in Tennis Ball Impacts
The curve from the paddle hung by a rubber band is an upside down parabola with a maximum location at about 6" from the tip. This location corresponds to the paddle's center of mass (balance point) where the effective mass is the highest.
Surprisingly, the paddle with the massive clamp (SW=56) has a higher rebound velocity than the paddle clamped to the concrete block at impact location above 6". This is probably due to the fact that the reflected shock wave has the ability to increase or decrease the ball's rebound velocity depending on whether there is constructive or destructive interference at the impact location.
Hand Held Results - Normal Grip
Can the above results be duplicated using a hand held paddle? Instead of shooting a ball at an artificially clamped paddle, the ball was shot at a hand held paddle with a typical grip strength. The rebounding velocities of the hand held paddle best match those of the massive clamp.
Is there a case to be made for impacting the ball in the 6" to 9" area? After all, the graph shows the highest rebound velocity there. There are two reasons to avoid this area.
1. The "sweet spot" (3" to 5" from the tip) is well named as any impact in this region creates little vibration in the hand. Impacts closer to the handle create uncomfortable vibrations.
2. The graph depicts the case where the paddle is stationary - a block - and when the paddle is stationary the graph accurately reflects the ball's higher speed in the 6" to 9" region . But there are many other shots where the paddle is moving - a drive, punch or dink. When the paddle is moving the resultant ball velocity is a function of the speed depicted in the graph plus the rotating paddle speed. Because the paddle is rotating, the speed of the paddle nearer the tip is higher and the resultant ball speed is higher when hit in the sweet spot area. For a detailed description of the paddle speed during different shots see Mapping the Sweet Spot.
Hand Held Results - Very Light Grip
It is possible to affect the rebound velocity with a very light grip. I was unable to closely duplicate the yellow "rubber band" curve. It's impossible to maintain a light grip as the handle is driven into the hand as a result of the impact in the 6" to 9" region.
Conclusion
Most players naturally move the paddle so the ball impacts near the sweet spot - the spot where annoying had vibrations are minimal and the rebounding ball's velocity is highest. Any impact in the sweet spot area is unaffected by anything happening at the handle meaning the ball speed is the same whether the paddle is gripped tightly, loosely or not at all.