first, let me take this opportunity to thank you for giving me access to your site for a week. i used it extensively and enjoyed it a lot.
i can recommend it highly and will subscribe to it
as to the decline of u.s. tennis. we europeans probably have the advantage of playing on slower surfaces, mainly red clay, in clubs and academies.
with the atp tour slowing down the courts, the fact that europeans are used to playing longer rallies and maybe working on shot selection more, probably pays off.