By the time Super Bowl XX kicks off at about 5:15 p.m. (EST) Sunday, the best part of the day could be over. Regardless of who wins -- and four out of five oddsmakers will tell you the Bears need only shower, shave and shuffle into the Superdome by halftime to beat the Patriots -- the lackluster history of most Super Bowls suggests that the most interesting part of the spectacle could be the pregame show.

NBC, whose unlikely collection of news, sports and entertainment divisions has allowed itself to become America's No. 1 network, will take a slightly preposterous, unpredictable path to game time with a two-hour presentation called "Super Sunday: An American Celebration."

It will start innocently enough, with a five-minute film called, "A United Nation," produced by Bob Giraldi, whose historical vignette was used by NBC to open the 1984 World Series. Giraldi's film will depict three scenes -- from a Minnesota farm, a Texas hospital and a New York City cab -- of how the Super Bowl touches American lives.

Then, NBC will turn expectations inside out.

The Blank Minute!!! Bill Cosby on The Refrigerator!!! Rodney Dangerfield!!! Tom Brokaw Meets President Reagan!!! Larry King Interviews Everyone!!!

Sure, there will be some conventional stuff -- profiles of Bears defensive coordinator Buddy Ryan and the Sullivan family, owner of the Patriots; analysts Merlin Olsen and Bob Griese discussing what each team must do to win; a look back at Vince Lombardi (without narration) and a feature called, "The Team That Time Forgot," focusing on players of the Super Bowl I losers, the Kansas City Chiefs.

But by and large, NBC will try to reach out, clutch our throats and shake us silly, right there in our living rooms. Even the family pet might be able to sense this pregame-show metamorphosis.

"There's that pressure to give people what they expect," said Michael Weisman, NBC Sports executive producer, "but we want to make (the show) riveting."

John Filippelli, the pregame show producer, said NBC wants to avoid what he calls "the video wallpaper syndrome. Traditionally, there are features on the starting quarterbacks, the opposing coaches, cameras in bars from the Super Bowl team towns . . . The bottom line is that we're going to get away from the feature-bar interviews-feature routine."

Giraldi's thematic opening should set the tone for NBC's approach. "The moment before the Super Bowl has everyone doing the same thing," Weisman said. "We really become a global village, more so than on New Year's Eve, Christmas or a presidential election."

After Giraldi, NBC will rely heavily on celebrity heavyweights to hold us until the coin flip.

Cosby will discuss the original Refrigerator, Fat Albert.

Dangerfield will be funny.

King will interview coaches Mike Ditka and Raymond Berry.

Brokaw will spend five minutes with the President, who, mercifully, will forgo the traditional postgame phone call to the winner's locker room.

Sooner or later, the game itself will begin. Dick Enberg and Olsen will be joined by Griese (diagramming plays on NBC's telestrator), marking the sixth time in 20 Super Bowls that a three-man broadcasting crew will be used.

NBC will have 21 cameras covering the field. There would be 22, but a Goodyear blimp floating inside the Superdome would have blocked too many spectators' views.

Despite the onslaught of manpower and equipment, NBC hopes to be prudent in its use of replays and let the game carry itself. Weisman said that the game clock will be shown more frequently than in the past and that NBC "might isolate on one key player up to 20 times in the game to follow the story line of how he's doing."

For all of the usual hype surrounding the Super Bowl, no aspect of NBC's six hours of coverage will be more anticipated than the "Blank Minute." Weisman's concept, originally just sort of a symbolic respite from the long day of hysteria, has blossomed into a major event.

The moment of nothingness will occur at 4:02 p.m.

"There will be visuals and there will be music," said NBC spokesman Tom Merritt, refusing to be more specific, for fear CBS might program its own minute earlier in the day.

Most folks, curiously enough, actually plan to watch the blank minute. This is patently ludicrous. Because every blank minute you waste is one you can never make up, I plan to account for every precious blank second and even have devised a schedule that could serve as a national model of sorts:

*:001 to 0:12 -- Cook veal marsala in the microwave oven.

*0:13 to 0:24 -- Apologize to my wife for being a jerk from 1982 to 1985.

*0:25 to 0:36 -- Complete my 1979 state and federal income tax returns.

*0:37 to 0:60 -- Read the jacket flaps of "War and Peace."

If all goes well, NBC might expand "The Blank Minute" into "The Blank Hour" as a summer replacement series for "Punky Brewster" and "Silver Spoons." Then again, ABC might purchase the concept outright to replace its entire prime-time schedule.