ST. LOUIS -- Once, long ago, when he was a National League catcher, Bob Uecker got out of bed in the middle of the night to go to the bathroom. Hiding behind the door in the dark was his roommate, Roger Craig, who'd lurked there for hours, just to scare Uecker half to death.

Now, it's Craig and his San Francisco Giants who are lurking in the dark, waiting to scare the wits out of the St. Louis Cardinals in the National League playoffs and, maybe, make some hair stand on end in the World Series, too.

The Mississippi River runs beside Busch Stadium here and not too many folks east of this creek know too much about the first Giants team in 16 years that has won anything. "They may not be {famous} now," said Craig this evening, "but they will be."

To say that the Giants are new to this sort of thing would be an understatement. A national TV producer warned Craig before Game 1 that, "We'll have a camera on you, so don't pick your nose." "Whadaya mean?" roared Craig. "That's one of my signs."

Postseason formal wear is not part of the Giants' traditional wardrobe. They host a playoff game in Candlestick Park about as often as a terrible earthquake hits California. Exactly as often, actually. The infamous Sylmar quake hit in '71.

Actually, Craig wasn't one bit fond of last week's Whittier shake, since he was on the 21st floor of a Los Angeles hotel at the time. "Helluva wakeup call," Craig said. "I thought Pete Rose would be managing here this week."

That's because Rose's Reds finished second in the NL West and somebody would have to have been found to replace the Giants. "Actually, when the cement started cracking, I thought it was all over," Craig said soberly. Instead, it is all starting for the 57-year-old former pitcher who, this week, begins what will probably be a long and successful run at the center of baseball prominence.

How often does a man who looks like a cross between Lyndon Johnson and Jimmy Durante, and whose two best-known major league seasons were 10-24 and 5-22, get to be a baseball folk legend as he completes middle age? The entire Bay area now says "Humm, Baby" -- that old-fashioned high school staple of infield chatter and Craig's favorite expression -- whenever anything good happens. Craig's wife, Carolyn (whom he went AWOL from the Army to marry), is even known as Mrs. Humm Baby.

How can you hate a manager who comes to the mound with the bases loaded in the ninth inning and says, "Get him out. I need a beer." How can you resent the gall of a skipper who says, "Jack Clark won't beat us," then walks the Cardinals slugger nine times in one series -- and gets away with a four-game sweep.

No wonder the Giants have become the fifth team in history to go from 100 losses to first place in two years. As soon as Craig took over, he issued an edict that, henceforth, no Giant would ever again curse Candlestick Park -- the coldest, least habitable spot for baseball in big league history. Even fans got a medal -- the Croix de Candlestick -- if they stayed in the park until the last out of an extra-inning night game.

Other teams hate Candlestick even more than we do, Craig told his Giants. At least we're accustomed to it. Make it a home field advanatage. Funny, nobody ever put it that way before. The Giants actually bought it. Now, they root for wind and raw mist, the kind that once prompted Willie McCovey to rationalize a missed fly ball by saying, "The peanut shells got in my eyes."

Anybody who makes a habit of "Humm, Baby" would naturally find a way to convince his club that the lowly Giants uniform -- which has not been seen in a World Series since 1962, nor in a world title photo since 1954 -- was, in fact, a badge of the highest honor. 'Deed he did. Craig discovered that the Giants have actually won more NL pennants than any club ever and have 45 players in the Hall of Fame, also the most. So, he dug up all the ancient photos and plastered the joint with 'em.

Of course, it helped to come up with a nifty keystone combo (as they used to call it in Humm Baby days) of Robby Thompson and Jose Uribe. When he came up, shortstop Uribe was named Jose Gonzalez. Later, he wanted to be known simply as Uribe -- like Liberace or Prince -- but the Giants balked. So, he settled for Jose Uribe, prompting Rocky Bridges to say, "He really is the player to be named later."

The arrival of Will (The Natural) Clark at first base was seminal. When you have an outfielder named Chili (Davis), shouldn't you trade for a Candy (Maldonado) to keep him company?

Finally, this summer, General Manager Al Rosen made the trades that put Craig's creation over the hump. The Pirates gave up their expensive staff ace, chubby old Rick Reuschel, for a discount relief prospect and then dealt Don Robinson for a box of batting gloves. The Padres were even more generous, giving up Dave Dravecky, Craig Lefferts and Kevin Mitchell for four guys who would probably make a great bobsled team. Since Craig could teach Tammy Faye Bakker the split-finger drop, most of them got better quickly.

Lately, mysterious matters have been conspiring to aid the Giants' cause. In what will probably be a long and difficult series with the veteran Cardinals, they will need all the help they can get. Already, St. Louis slugger Clark appears to be sidelined until Game 6 at the earliest. Willie McGee has a bad wrist. And this afternoon, the Cardinals' scheduled Game 1 starter, Danny Cox, decided he could not pitch because of a stiff neck. Last time the Cardinals were on October's center stage, Vince Coleman was consumed by a tarp.

"What am I," said St. Louis Manager Whitey Herzog, "a guinea pig?"

While almost everyone here assumed that St. Louis was in dire straights without Cox, Craig was the one fellow who strongly disagreed, figuring he'd love to be in Greg Mathews' shoes, pitching a huge game on almost no notice. In fact, he once was.

As a rookie in 1955 for the world champion Dodgers, Craig warmed up in each of the first four World Series games, but never got to pitch. He was downcast. Manager Walter Alston asked, "How do you feel, kid?" Craig answered, "I want to pitch." "Good," said Alston. "You're starting the next game."

"It was a huge boost," remembers Craig. "I was tired, but I pitched decently and won."

As Craig feared, Mathews was sharp here tonight and won, 5-3. The southpaw even chipped in an end-of-the-bat two-run single in St. Louis' three-run, game-breaking sixth inning.

However, these playoffs have just begun. Before they're over, Craig and his club figure to get to say "Humm, Baby" a few times, and maybe even jump out from a couple of dark corners.