First round of testing.
Conditions: four frames Wilson RF 97 Autograph, same strings (Babolat VS Touch 16 (natural gut) on the mains, RPM Blast 17 (poly) on crosses).
Stringing:
1) Reference: same tension on all strings, 56 Lbs mains, 54 Lbs crosses, DT = 39 (per ERT-300).
2) Sergetti: Reference 55 Lbs, DT = 39.
3) Proportional to String Length, tensions calculated based on 56 Lbs main / 54 Lbs crosses, DT = 38
4) Dire Desire, claculated based on 56 Lbs main / 54 Lbs crosses. I used SDST of 0.227 and deflection of 28.5 for gut and SDST of 0.15 and deflection of 26 @55 Lbs for poly, based on data from the string testing article referenced in DireDesire desctiption and Tennis Warehouse string testing data.
Algorithm does not work well for poly and gives negative tension for some strings, all values that were negative or less than 11 replaced with 11 Lbs [the lowest tension on my machine], DT= 36
DT was measured right after stringing with ERT-300 tennis computer. All racquets were strung on Gamma X-ELS.
Testing was done with a ball machine, each participant made several rounds swapping racquets and was hitting for at least half an hour, mostly from the baseline. Participants were asked to not look at the labels and refer to overgrip colors. At the end, they were asked to arrange racquets from the best to the worst.
Known limitation of testing: all three people in the test today have been playing using Sergetti tension pattern since last summer. This fact may have skewed the results somewhat, since there may be a certain expectation how the racquet should feel.
The results were surprisingly similar. Everyone noted right away that racquets feel quite different, but one had to go through several rounds to come to a conclusion what feels better and rank the racquets from best to worst.
A:
1) Sergetti
2) Proportional to String Length
3) Dire Desire
4) Reference
Note: 1 and 2 felt close.
N:
1) Sergetti
2) Dire Desire
3) Proportional to String Length
4) Reference
Note: 2 and 3 felt close
M:
1) Sergetti
2) Dire Desire
3) Proportional to String Length
4) Reference
Note: 1 by far better than 2-4.
It was noted by M. and A. that Reference felt much stiffer, M. also thought it had less power.
The scale of differences, in my opinion, is similar to what one may feel when testing different racquets, or what one may feel when testing different strings. In a way, it is a third level of fine-tuning on top of the the level of racquet and the level of strings. When racquet feels right, and strings feel right, this is the way to make it feel even more tuned to the one's idea of "perfection".
I hope to invite a few more people (this time, not familiar with proportional stringing) over the weekend.
If someone is in Portland, OR, and is interested in participating over this weekend, shoot me a PM - we might work something out, most likely early in the morning when ball machine and scattered balls do not disturb other people on public courts. The more people, the more statistics, the more interesting