Watch him talking to kids who’ve been practicing tennis on one of the 10 indoor courts in the gorgeous new Lifetime Athletic in White Plains, N.Y. He doesn’t just autograph his new book, “Changing the Game” (New Chapter Publisher, 319 pages, $26.95), for them. He takes the time to explain the fine points of the game – their game. And the kids, hardly bigger than the tennis bags they are carrying, really listen.