If you’re looking for a court where you can always get in a couple solid hours of hitting without worrying about the vagaries of a loose net, the distractions of nearby, loudly arguing basketball players, or the fear of waiting until past dark to start your warm-ups, you are in a city blessed with no shortage of options. But if you want a court that, despite its innumerable scuff marks, too-close fence, and proximity to a legion of drunks, can make you feel as if a vital part of the world is paying attention to you, well, then you have no choice at all- you’ve got to play at Cal Anderson Park , where AstroTurf loungers and passersby alike will delight in cheering your Boris Becker serves, Ivan Lendl forehands, and Rafael Nadal fist-pumps (if not your Maria Sharapova grunts). The fact that there’s only one court means you might wait to play, but once you’ve taken the stage, you’re the only show in town. JONATHAN KAMINSKY 1635 11th Ave.