It is the only show. Not a prelim. Not one of 40 or 50 "special" days on the home schedule. The fourth annual Cracker Jack Old Timers Baseball Classic at 8 o'clock tonight at RFK Stadium does what other old timers games do not: puts the veterans, who helped make the game a part of our culture, on center stage.

"In its concept, it is different than any other old timers game," Hall of Fame pitcher Warren Spahn said. "We're very proud that there are so many nostalgic fans who want to see our game, not a preliminary to a major league game. Two of the darn things have been in the rain, and the players, to a man, have said, 'Let's play.' It's that same enthusiasm that they used to have."

Dick Cecil, the game's managing director, said, "We gather them for one night, to go back to the way it used to be, the way it was."

That one night is tonight, and promoters are expecting a crowd of about 30,000. The game will be telecast Saturday on a delayed basis by CBS.

There are a number of reasons for the players to come, including $1,000 and the contribution Borden, Inc. makes to the Association of Professional Ball Players of America, which helps retired players who have fallen on hard times. But they also want to see a few old buddies.

"It's really a thrill to see people trying to display the skills they had," said former Senator Jim Lemon, who will play in the game. "The camaraderie is there and friendships are renewed."

"It's exciting to see guys that you played with and against, the (Sandy) Koufaxes and (Juan) Marichals," said former Pirate Bill Mazeroski, who, in 17 years, played in more games than any other National League second baseman.

Does a Mazeroski remember how a Koufax pitched to him? "I don't think he worried too much about how to pitch people," Mazeroski said with a laugh. "He could throw it by most anybody when he had that stretch of about eight or 10 years. He probably was one of the best that ever played."

Koufax surely helped the evolution of the baseball adage that the game is 90 percent pitching. But the Old Timers Classic might be a little different. When Luke Appling, 75 years old at the time, hit a first-inning home run off Spahn in the first game in 1982, the roles in this re-creation of history were cast.

The game will last five innings. Thus, batting practice, which begins at 6, may be as much fun for fans as the game. It is, after all, more of a show.

"The whole name of the game is to get ball over the plate and let them hit it as far as they can," said Hall of Fame pitcher Early Wynn, who never was known to be so kind to hitters in his playing days. "They don't want to see a pitchers' duel. Just get it over and, hopefully, they won't come back up the middle with it too hard."

Sixty-one former players will be in uniform tonight, including 21 whose busts are hanging in a museum in Cooperstown. The National League, the home team, is managed by Birdie Tebbetts. The American League will be directed by Harvey Kuenn, with assistance from coach Chuck Stevens.

The game has caught the attention of the nation, including some current major leaguers.

"I saw Reggie Jackson a while ago," said Hall of Famer Robin Roberts, who will appear tonight. "We were talking about this game and he said to me, 'I can hardly wait to play in that game. It looks like a lot of fun.' Here's a guy still hitting home runs in the big leagues and he wants to play in this game. I told him he better not show up. We won't pitch to him."