out of sincere curiosity, how do you wear out 24 rackets in a couple of years??
I play a lot, and restring a lot, and hit a pretty big ball. Stringing tightly, with poly, also contributes because the strings don't absorb as much of the impact, and it goes straight to the frame.
I had 17 N90s and pretty much used them up (broke or wore out) in I guess a bit over 2 years.
Switched to the K on 1/1/08 and have broken 3 or 4 so far (not through breaking in anger just wore out and broke).
I have a little book and I keep track of how many times I string each frame so that they wear evenly.
I have 16 in rotation now, and 3 brand new backup ones. I will probably get 6 more in June or so and have that 9 done so I will probably make it past my orig estimation of 1/1/2010. If that 9 will let me get another year out of the frames, then I will be set.
But I have found that I average about a racquet a month over the course of a year. So if I play with 3 racquets in a rotation, they wear out in 3 months, if I play with 12 in a rotation they last a year.
J