I've been using the Prince Tour 100T ESP for a few months now. It is an open 16x16 pattern so I know I'll break strings quicker. I have not had a problem with most polys but my new favorite Discho Iontec broke both times at the top of the hoop. The first time it took 3 sets but the 2nd time it was only 3 games! For those who will say "Just hit the center of the strings", you have never seen me play. Shanking is in my blood. Both times where the Iontec broke was between the last grommet on the side and the first O-port. The rackets are new and it happened on two different frames. I inspected both and don't see anything suspect in those areas. I think this string is just prone to shear stress. I really like stringing this frame with poly at 60# to help with control in the open pattern and it also seems to help with string snap back. So I've had the following thoughts on how to help the strings last longer: 1) Clamp the top mains away from the frame and deal with whatever tension loss happens. 2) Use string savers along the top cross. 3) Power pads in the problem 2 areas at the top? 4) Lower tension if all else fails. Any ideas would be greatly appreciated.