Whither the next great tennis rivalry? Maybe don't hold your breath

Tennis has been awash for nearly 60 years with stellar rivalries, especially on the men's side. But it's becoming clear the next great one might not be around the corner The Australian Open exists on its own in the tennis calendar at the start of the year - not really connected to what came before or what ensues immediately after; it's nearly five months removed from both the US Open that precedes it and the French Open that follows it. For most followers of the sport, the real start of the cale...