Ray Lake drinks water out of a tennis ball can. He’s been doing this for years. He pops the top, empties out the three yellow balls, and fills the can at an Igloo cooler that’s stationed between the indoor courts at Woodside Health & Tennis Club. Five days a week, the 79-year-old semi-retired psychiatrist can be found vigorously volleying with players half his age. Lake is hard to miss at Woodside. His build is slight and he speaks softly, but he’s a flashy dresser. He has swag. He warms up in bright, multicolored Fila jackets that he’s owned since that sportswear company sponsored him in the 1980s. He wears jewelry on the court — two silver bracelets, a silver necklace, a gold watch and a big gold ring — and often a black bluetooth earpiece in one ear and an iPhone hanging sideways at his waist. He swings an unusually large racket made by a company called Gamma. And he knows how to use it. Lake has been competing in United States Tennis Association league matches since the 1970s. ...