Zinsser (On Writing Well, Willie and Dwike, etc.) hits a four-bagger once again with this delightful, poky look at baseball's annual warm-up. Why spring training? It's the only baseball topic Zinsser can think of that hasn't been written to death. Why the Pittsburgh Pirates? It had to be a middle-American team with a long history, and from his beloved National League. So Zinsser finds himself in Brandenton, Fla., a podunk town where Dizzy Dean once pumped gas, snuggling up to the brash, upcoming Pirates of 1987. Fie chats at length with general manager Syd Thrift--who looks like "a field hand in a movie about the Old South" but displays the baseball acumen of Durocher and Stengel combined. He eyes nervous rookies; edges up to a scout in the bleachers; interviews Brandenton's own Edd Roush, the oldest--and probably most cantankerous--living member of the Hall of Fame; talks balls and strikes with veteran umpires; hears batting coach Milt May elucidate the Art of Arts; in general probes the fathomless mysteries of baseball. This seems the opposite of the Bernstein school of investigative reporting: no revelations (the only headline Zinsser mentions, a forgotten classic, comes from another era, the day after Dizzy Dean was beaned. It reads: "X-RAYS OF DEAN'S HEAD SHOW NOTHING"), just a group of men being boys on the grass in the sun, and one reporter ("a codger. . .crammed with baseball memories") pleasantly asking how and why. By the fall of '87, the Pirates came in second place--a major step forward for a team that had finished 57-104 in '86. Zinsser's book, on the other hand, may well capture the pennant in the baseball book race of '89. Delightful.