SINCE WRITING BOOKS about oneself wasn't the vogue thing to do when he was a ballplayer, circa 1947-63, Edwin Donald (Duke) Snider, the pride of the Brooklyn Dodgers, has waited until now, the age of jock-authorcy, to publish his autobiography, "The Duke of Flatbush."

The book, 288 pages long, is filled with memoirs of the Brooklyn Dodger heydays of the 1950s, when Ebbets Field wasn't an apartment complex and they didn't play World Series games at night and New York City had centerfield covered with Willie, Mickey and the Duke.Pee Wee Reese and Gil Hodges and Carl Furillo and Roy Campanella and Don Newcombe and Jackie Robinson are in there, the Boys of Summer played by themselves, and if these names won't sell a $17.95 hardback to baby-boomers who drive Saabs in 1988, what will?

There are many Duke Snider stories, told in the first-person.

For example, there's this story about Duke having dinner with Willie Ramsdell, a pitcher for the Chicago Cubs and a former Dodger teammate: We'll pick it up in the third paragraph.

" . . . The Dodgers were in Chicago in 1952 and Willie invited Erv Palica and me to his house for dinner. While we were eating he told me he was pitching against us the next day. I said, `Willie, you wouldn't throw me that nickel curve of yours, would you? I bet you'll just give me that knuckler. You wouldn't have the guts to show me that rinky-dink curveball, would you?"

"Sure enough, the next afternoon he dared me with his curveball and I hit it out of the park. As I was rounding second base, I was laughing hard and he hollered, `You S.O.B.?! That whole conversation last night was just a setup!'

"The next day I felt terrible when I heard the Cubs had sent Willie to the minors, farmed out to the Los Angeles Angels. I tried to help make amends by renting him our house (in California). That made me feel better, but it didn't change Willie's feelings. I arranged for my mom and dad to meet Willie to give him the key. Mom was talking with Willie and she said, in her innocence of baseball matters, "Willie, you took care of Edwin, didn't you?"

"Willie said, `Listen, it was Duke who took care of me! If it wasn't for that son of yours I wouldn't be standing out here today in California!' "

There are many other Duke stories, told similarly, and as the story of Duke Snider's rather remarkable 18-year Hall of Fame playing career unfolds, as it's revealed that he hit more home runs than any player in baseball in the mid-'50s - more than Willie and Mickey, more than Gil and Campy, more than Musial and Kaline; as it comes out that here is a man who made some of the greatest catches of alltime, and hit so many tape-measure shots onto Bedford Avenue beyond the rightfield fence in Ebbets Field they renamed it "Duke's Alley," as all this lore unfolds, so does something else.

The Duke also has a tape-measure ego.

This is a book equivalent of watching home movies - in this case in the Duke's own den. Look, here's one of me beating the Giants to win the pennant . . . Here's one of me coming through under pressure . . . Here's one of me appearing with Ed Sullivan on "Toast of the Town" . . . Here's an old New York Daily News clip that says I played centerfield like DiMaggio."

Duke Snider played baseball in that grand era between then and now. The era that went from Musial and The Splendid Splinter to Reggie Jackson and Pete Rose; from transistor radios to color TV; from World War II to Vietnam; from baseball's monopoly to shared-time with the Super Bowl (and, for some of us, from summer vacations to getting a real job). He was a rookie with Jackie Robinson, when the color line was broken; he was there for Don Larsen's perfect game, for Bobby Thompson's home run, for both Johnny Podres and Sandy Koufax. And he was a part of, as Frank Layden says, the beginning of the decline of Western Civilization - when the Dodgers moved from Brooklyn to L.A.

His book barely touches those bases.

Instead, it is an account of someone talking about himself.

"It Ain't Braggin' If You Done It," and the Duke done it.

But I already knew that.

Besides being the worthy foe of Mantle and Mays, besides playing for the most lovable team in baseball, besides hitting 407 home runs, Duke Snider was something else.

He was my favorite player.

He was the best there ever was, the best there ever will be. He was bigger than Mantle, bigger than Mays. He was bigger than life.

Why, after all these years, did he have to go and write about it?