The best way to ensure that you'll never be wanting for a tennis match is also the most expensive: Join a tennis club. That's not always possible, or even desirable, but take heart—you can find a game if you know where to look. Every city has a set of public courts that, for some reason, becomes the mecca for tennis all-comers. In Seattle, it's the Lower Woodland courts at Green Lake. A few of the 10 courts could use resurfacing, and the southernmost pair take a while to dry after it rains, but this is the best bet in town for a tennis junkie to show up stag and find a good match. At first, playing there can be daunting, because the cabal that monopolizes the courts tends to be quirky, male, and insular. But there's no use fighting them. They were there long before you and will be there long after you leave. Better to just introduce yourself and learn their rules. It helps to have some game (current or former college players will always find more willing hitting partners than they have time for), but there's always a range of abilities. If you're a 3.5 NTRP or above (if you don't know what that means, go take a lesson or play somewhere else), someone will hit with you. And all the folks milling around, waiting for a court, only provide extra incentive to put on a show.—Huan Hsu Aurora Avenue and 59th Street North (best access via Green Lake Way North near the golf course), 684-4075.