The Grand old Slam of tennis is the local pro here giving many lessons from experience. . . . ""And if you're really serious about tennis, and care to invest about 22,000 hours on the court, you stand a fine chance of overtaking and beating me. By that time I'll be around seventy."" The Aussie with the King Kong right arm was the first to win the Grand Slam . . . the singles championships of Australia, France, England and the U.S., making him the Player of the Year and netting all that prize money. There are chapters of practical advice such as ""Mental Preparation"" or ""Don't Change a Winning Game (And Always Change a Losing Game),"" and Rod Layer's personal life is thrown in between serves. It's always a toss-up between the gruel backstage and the duel on court (particularly if your pregnant wife announces her divorce intentions before the third set) but it's an exhilarating and amusing game-into-book.