"Blind" Stringing for Coach J

J is a tennis coach. He's part of a group that I hit with quite regularly. 

After seeing so many weird strings and stringing patterns on my rackets, he asked if I could do one fancy setup for him on his racket. It's been a while since I did a "blind" stringing (link), so I gladly agreed!

(What "blind" means is the racket owner will have absolutely no clue how the strings were done until after the playtest.)

J has a very complete game. I cannot think of any flaws. Since he eschews syn gut, I decided to string a full bed of it to show him what can be achieved.

I have two objectives:
1. increase sweetspot size,
2. increase spin.

The racket is supposedly a made in China clone of a very popular brand.

At first look, I noticed it strongly resembles a squash racket. And the 16x20 pattern even comes with four shared holes! Amazing!

The racket specs affect feel and tension tremendously. Primarily, swingweight (link) and flex. So, before stringing, I checked. 

The gripped racket weighs 300g before strings, about 315g after. Balance should be 33cm strung. I estimate the swingweight to be between 300-310. That is low for a ntrp 4.5-5.0 player.

From a pseudo "flex test", this thick beamed racket is indeed as stiff as it looks. Using my RA72 PSC6.1 as a comparison, this one gives less!

With the low swingweight and very stiff flex, I decided to drop some tension from J's usual 60 lbs to soften the stringbed slightly, tame some power and add some "cushioning" for comfort.

To simulate the full poly feel that he prefers, and to improve tension holding, I pre-stretched the syn gut by looping the string around my chin-up bar and hanging my dumb bells on it. The amount of string stretch is monitored. When the targeted 1.5% inelastic elongation was achieved, the weight was removed.

Full proportional stringing was done starting at 48lbs to compensate for the stretched string and less lively feel. The pre-stretch would make it play tighter than 48lbs so control issues would not surface. My plan was to replicate as close a stringbed stiffness (at impact) as J's preferred Pro Kennex racket. Or just slightly softer.

The 16x20 pattern was also "converted" to 16x18 to equalize string tension pressures on the frame. This step accounts A LOT towards enlarging the sweetspot.

With proportional stringing, the other little known benefit I observed is the increase in spin. This is very clear to me since I'm at the receiving end of shots hit by my partners' proportionately strung frames.

Nothing beats a real playtest, especially matchplay. I will post as soon as J updates.

Below's some pics...

The specs.

The shared holes. (I skipped a set of shared holes)

Playtest:
- J felt that the tension was a little too low and there was a lot of string movement which had to be straightened out between points. If not, the stringbed can be a little unpredictable. 
- However, he found the "bite" was quite good which translated to pretty good spin.
- Overall, J rated this playable.
- I'm pretty sure he did not like the setup. No surprise though, considering he gave zero hints on how he liked his rackets to be strung. Moreover, this was a backup stick that I don't even remember seeing him use even once.
- Enough of "blind" stringing for me...