An Experiment on Tension vs Power and Control

Whenever I recommend someone to drop their string tension, they would all unanimously comment on how uncontrollable the stringbed would "trampoline" and all control would be lost.

I asked a doubles group if they would be interested to conduct this tension test and they agreed immediately. One offered three of his similarly matched rackets for this experiment. Cost of strings were shared.

Only tension differed, and ranged from 20lbs to 80lbs.

The methodology was kept simple:
1. Rackets
Out of a total of 7 rackets, three different models of rackets were used. All had 16x19 stringbeds, RA stiffness ratings in the 60s, total weight between 328-344g. Balance between 31.9-32.5cm.

2. Strings
The same synthetic gut was used and strung using the same one-piece pattern on the same machine.

3. Power
Since we do not have sophisticated radars, we measured it subjectively. While two were playing singles, the other two non-playing would observe their serves and groundstrokes from the net and at both baselines behind the players. All four would record their observations, with 1 as lowest and 10 highest. Differences in depth of shots were very apparent. Players were rotated to allow everyone to test.

4. Control
Different serve placements were attempted for flats and spin. Groundstrokes were targeted at corners using both flat and topspin shots for both wings. Both players and observers would rate the stringbed control independently.

The chart below summarises our group findings.

*The three matched rackets were strung at 30, 50 and 70lbs.

At 20lbs:
Hitting deep groundstrokes was almost impossible. All had to raise the net clearance to above 6ft to clear the service line. Topspin shots curled down too much and we had to flatten our shots to hit deep. Pocketing was so deep the rebound was delayed.

At 30lbs:
The stringbed felt so much tighter than 20lbs. The delayed rebound was gone and the stringbed became much more predictable. Power was still low but the less pocketing from 20lbs gave us a better transfer of energy to the ball. Still had to flatten our strokes to hit deep. 

At 40lbs:
Coming from 30lbs, all noticed a huge sharp increase in power. If there was any trampoline, this was it! Too much power and too little control. We recorded the most number of double faults and out balls at this tension.

At 50lbs:
The trampoline from 40lbs seems to be reined in. Control stepped up significantly. However, we were split. Two felt it was playable but could not swing freely and confidently. Two felt it was neither here nor there and actually preferred the 30lbs!

At 60lbs:
It felt dead! It could be the brand of syn gut we were using or that we started off from 20lbs. There was a huge shock with every ball impact. It felt familiar. Probably something we felt all the time hitting with our regular sticks and tension but had become numb to it. Among all the tensions, the vibrations appeared highest at 60lbs.

At 70lbs & 80lbs:
There was very little ball feel left. Almost no pocketing. The stringbed felt "slippery" whenever we tried to spin the ball. Could be because of the low pocketing and almost zero sliding of the strings. Because of the lack of "bite" and power, we resorted to hitting the ball flat and it played quite well that way. Except for the high unforced errors due to too low net clearance. We hit the tape too much.


Note:
This "test" was done some months back. We had scribbled the observations on a few sheets of paper which we lost. A clown just found it in his messy car boot!!!