I thought I'd start a thread on my experience with arm pain, my move to a steam stick, the move to a full poly setup, my experiences, and how it relates to the current TW article on how strings go dead. So I've played the last 4 years with Yonex RDiS 100's. I started out initially with multi mains and crosses. In a quest more spin I dabbled with full bed poly. Poly in this stiff frame eventually led to tennis elbow. Did the rehab, switch to all gut, TE became manageable. I then found the TW forums and started to read up on strings. Switched to gut mains with MSV CoFocus crosses and spin was better than all poly and my elbow loved me. I could get 12-16 hours before I popped the gut which was very acceptable to me as I string myself. Fast forward 2 years and the 99s comes out. I buy a pair and start to experiment with strings. Becomes evident very fast that nothing except poly in the mains is going to work. I can pop gut in under an hour, multi shreds and pops in under 30 minutes. OGSM lasts maybe 2 hours but stops sliding in under an hour. So, the quest for an arm friendly poly setup starts. I'm looking for a fairly soft poly main, that can keep its tension. I'm looking for a cross thats smooth and hard but yet still soft enough to not give me problems. I went to the TWU and pull up the top 8 poly strings that have the lowest stiffness ratings. I try them out. I settle on BHB7 for the mains because it seems to hold its tension the best and feels soft. This takes weeks of experimenting. I was using OGSM as the cross because its cheap by the reel, I know how it feels, and I can evaluate the mains compared to each other and not compared to the cross. The downside with BHB7 17 is that it pops right around hour 4. As I string myself this isn't terrible, but I move to 16 so I can get 6 ish hours out of it. I ten start to work on the crosses. Although OGSM works over time it "roughs up" and the mains stop sliding as well. BHB7 is very soft and grooves. The OGSM does not which is good and creates a rail effect. However since the OGSM gets rough and pebbly feeling the friction goes up. I tried the other 7 strings that I tried as the main in the cross and settle on Polyfiber TCS 17. It plays a lot like OGSM in the cross. Its controlled. Its softish. It losses tension very fast as a main, but its seems fairly stable as a cross. must importantly it doesn't "rough up" or dent at all. The BHB7 slides on it till it literally saws itself through and pops. These are two of the softest polies out there and the arm effect, for me, is just as soft as gut/msv on the RDiS. I get more spin that the RDiS because of the open face. I have to restring more often and the feel at the net isn't as good. Overall I'm happy. What I wanted to do though is discuss WHY this is. After reading the professors article on strings going dead I was thrilled to see 2 of the strings he tested are BHB7 and TCS. What I noticed as that BHB7 does indeed hold tension the beast as I personally experienced. I also saw that its has a higher angle of deflection. I noticed this with the steam but I thought it had to do with the open face. I'm not sure I get enough hits in under 6 hours to get to the far end of the graph but I'm sure some is from the string. I find it interesting that the static CoF goes up the highest with the BHB7. I surmise that's because its so soft and has a tendency to groove. I think that's why my quest for a slippery cross was so important. Based on the way the professor described it its directly offset by the fact it doesn't lose tension as fast thus causing the string the play similar to it starting point. Two forces at play.. Higher friction but less tension offsetting each other. I think for people who want strings to play uni-formally through the life of the strings these forces need to offset each other as much as possible. In the past I experienced arm pain from Polys that locked in place. I'm sure of this. I find that the more string movement there is the "softer" this feels on my arm. When I tried some of the harder polys as long as there was movement the stiffness wasn't as much of an issue. I think this is key. I think that after poly ages, the stiffer polys that lock into place are the main culprits. I don't know if its because the energy channels down into your arm instead of going into string-ball movement or if you swing harder trying to pop the mains out of the channels to get the spin you need. I really don't know. I DO know in my case that the locking of the mains and crosses is what "hurts". So and the end of the day, for me, with my swing speed, in my frame, BHB7 with TCS crosses plays the same till breakage. As the professor stated there are multiple forces opposing each other. I think its entirely possible there is no "best setup" for everyone. Since swing speed and frames differ along with arm tolerance I think optimal string choices differ for every case. I encourage people to read that article then go out and put it to use to figure out your best string setup if indeed you are looking for a poly setup. Those are my experiences with the whole thing. Hope it helps someone.