You're way too kind Mikeler. (Actually, you're a really nice guy and the whole message board appreciates that!) I forgot the last hypothesis: Everyone is wrong about gut/copoly. It does not generate more spin than other setups. What actually happens is that the rebound angle is very high. This forces the player to close the racquet face to lower the trajectory of the shot and keep it inside the baseline. Closing the racquet face produces more spin, but this is a player-dependent effect, not a true inherent virtue of gut/copoly. This is actually a possibility. To date, there have been no published tests of a gut/gopoly setup under controlled conditions, so we do not know that gut/copoly is more spin-friendly than any other setup. We can assume this setup is quite powerful, so if players are closing their racquet faces to compensate for a high launch angle, and thereby generating more spin, the combination of that racquetface angle-dependent spin and the inherent power of this setup would create a heavy, dipping ball. Mikeler might not have given himself enough time to adjust to the high launch angle by closing his racquet face, or may have reduced the steepness of his swing (another compensatory strategy used to deal with a high launch angle that would result in less spin, rather than more), and so his results were a fast ball with not so much spin. I hate to write this: but who the hell knows? On the other hand, every bit of info we have on strings and spin suggests that gut/copoly does produce more natural spin. But that info also suggests that if the tensions are too low you won't get more spin and only a high launch angle. So I think this particular hypothesis is probably blul siht. It's more likely that your tension was too low in that big, open pattern. I think you could probably up the tension by 5-10 pounds and not endanger your arm. But you know your body a zillion times better than me. Another thing to try, and I honestly cannot believe you didn't try this instead of gut/copoly, is gut/Monogut ZX at 56/54. Monogut ZX is half as stiff as that Yonex copoly! USRSA has a nice deal on the 17g version for members.