Originally Posted by pvaudio
That was exactly my point, it's a conundrum. Greater stiffness yields higher spin potential, but greater elasticity also yields higher spin potential. My theory, which is my reasoning alone, is that gut yields good spin because it is so elastic that it's able to overcome a lot of the string-string friction. Kevlar, which has extraordinary ball-string friction will also yield good spin potential. Whether this is true or not, I have no idea, but I DO know that it's because poly can combine the best attributes of both of these string types and meet in the middle that it's far superior than either with regards to spin potential.
That makes some sense, but I am not so sure that poly can really exceed kevlar in spin potential let alone be far superior. I feel that because poly puts more power on the ball that many players will see a better hop off the court because of the polys power not spin, so then many would think they are getting more spin but actually it is more power.
If we are talking about just spin I think that kevlar actually produces more spin than poly.