I'm a doubles varsity player in high school currently looking for new string. I have my own machine now and am just learning to string. Currently using a Babolat Pure Drive GT strung with Gamma Live Wire XP 17 at 60 lbs (which will be cut out as soon as I find new string!). I use moderate spin on my groundstrokes. I like the string, but I think it's a little too crisp for my liking and prefer Live Wire Original. Also, I find that it is very difficult to generate spin with these strings. I have a history of shoulder problems, but that seems to be going away. Recently, I picked up a friend's racquet (Head Flexpoint... not sure of the model though) that was strung with poly at 55 lbs. The string wasn't branded, and he wasn't sure what string that was (it was his back up racquet). When I hit with it, I could NOT believe it was poly! It felt relatively soft, but I could definitely tell it was a poly because there was no string movement and no string notching. However, the strings were loose, which probably explains the comfort I found from it. The topspin in my shots were very noticeable compared to my setup of Live Wire XP at 60. Unfortunately, I do not know the string's name and neither does anybody else. Since I enjoyed my first experience with poly so much, I was looking into softer 17 or 18 gauge copolys to string on the mains at a low tension... say 55 lbs. On the crosses, I plan to use a multifilament at 57 lbs or so, depending on how much control I need. Having a history of shoulder problems, do you think this would be a good choice for me? I realize that my racquet is very stiff as it is and poly would blow my arm away, but I was wondering if lowering the tension on a softer poly would help? Maybe I should just stick to a multi/synthetic gut hybrid as other users have suggested to me? I'm thinking Pro Hurricane 18 or Tecnifibre Promix 17 on the mains at the moment and perhaps Isospeed Professional on the crosses. Any suggestions or tips are greatly appreciated.