From what I have read about Poly stringing and the way Fed strings his frames, he used to have Poly in the mains and gut in the crosses. But now it looks as if he has reversed this.. I also saw in Racquet Sports Industry Mag that he and Hewitt both put the Gut in the Mains and the poly in the crosses. Can someone tell me with absolute certainty if this is true ? And if so, what is the purpose of this ?