INSPIRED by the slogan "Nothing but fun," this is a gay, light - hearted book. There is many a chuckle in the epigrams by, and anecdotes about, great masters. The "bright games" are quick and clever - sharp duels of nimble minds, with annotations that highlight the fine points. The magical problems, endings and "flights of fancy" are all special favorites with Chernev - the kind he treasures in his famous little black book. Most attractive of all: Chernev's candidates for the 15 most beautiful games of all time.