The "bad boy" of the international tennis courts in the 1970s is the author of this surprisingly good novelhis secondabout the romance between a temperamental former tennis champion and his adopted teenage daughter. Though rich in play-by-play action and at first glance a jet-set soap opera, the book succeeds best as a character study of a gifted player facing the sobering reality of aging at 35when he has barely become an adult. Nastase, known for his impish humor on the courts as well as his intractable disposition, takes himself a bit too seriously and misses a few opportunities to build suspense. But he nevertheless makes the reader care for protagonist Istvan Horwat and his rebellious ward. This smooth narrative would probably be a popular success even if the author weren t famous. Joyce Smothers, Monmouth Cty. Lib., Manalapan,