Dragy said:
I was interested in such an experiment myself, but had not enough experience and resources to hold one. Missed one held by TWU in 2019.
http://twu.tennis-warehouse.com/learning_center/freehandheld.php
Long story short, no difference in rebound velocity if a ball is blocked by free-to-move racquet vs hand-held racquet. Just too short contact time for the frame to transfer impact all the way to the hand and the resistance - back to the top. All comes down to precise sweetspot striking. So no body mass contributing directly during contact - just the hoop and it’s speed.
-Good find here but maybe more to this than meets the eye.
The best COR (as you see in the chart at 20-25 cm or about 9") is closer to the throat than the areas normally called the sweet-spots. More COR is more power with less hoop speed. Since hitting out at the sweet spots can cut power to about half, then why not hit nearer to the throat which gives more power and control for less effort on certain types of shots? To get as much power further out on the strings, the racket must be rotating the tip around fast enough to compensate for less COR. That rotation if over-done or improperly done can create several stoke problems.
Congruent Tennis Creator
PTR Instructor
Great insights and information. There are several ways to come at this issue. It seems that traditionally players and coaches are looking at strokes primarily from a max power perspective. In the Congruent System, I established evidence showing that players normally have an excess of power available, then submit that chasing power is not the best direction to approach technique issues. If players can accept the idea that technique is more about controlling the shot than powering the shot, then we can pursue technical methods that are willing to trade off minor amounts of 'top end' power or 'potential power', to pursue superior control functions. Interestingly, better control can lead to much better "usable or avg power" as a result.
In this case, it would seem that due to the superior power near the throat, we can get similar power levels with a less aggressive swing style. It would be interesting to have an app where we could input the factors to see the effect on power output. For instance, if we slowed the swing from 60 mph to 55 mph...contact at 23cm from the tip instead of 10cm and slowed the rotation around the handle from 2 to 1.5.....the idea would be that the cleaner contact at 55 mph swing and less RH rotation, combined with the more powerful contact area could register similar power levels at a far more repeatable level of execution.