From all over America - from Washington state to Washington, D.C. - they came to Falls Church for last night's United Baseball League all-star game on Roger Duncan's kitchen table.

Some pitched tents in the backyard. Others slept under the banana tree in Duncan's Marauders even put his sleeping bag under the poisonous diffenbachia dumb cane plant in Duncan's dining room.

The travel, cost, inconvenience and even the ridicule of friends were all worth it to be there when Ji Palmer, the 31-game winner of the Nassau Bombers, faced Bert Blyleven, Cy Young winner of the Manhattan Blue Jays.

The United Baseball League - the "UBL" to the few who know of it - is perhaps the most complex, fascinating and potentially obsessive parlor game devised.

The game is played with two 10-sided dice, cards that rate individual players in every category from "gopher-ball factor" to frequency of hitting into double plays, and five "play charts" explaining what each roll of the dice means.

Its 16 members, each an owner of a franchise, is arguably, the most sophisticated and fanatical baseball fans alive.

Before anyone snorts, "Ha, just another glorified Monopoly game with dice," one thing should be made clear, UBL is serious business.

Last night, the National Conference manager decided to let Pete Rose try to stretch a double into a tripple because "the outfield grass we wet. We had had a rain delay. In the kitchen?

On a single UBL play, the two 10-sided dice could conceivably be rolled as many as 17 times, producing an incredible number of ramifications. However, five rolls are about average.

The first roll of the dice determine if the batter walks. The UBL system naturally takes into consideration the pitcher's control rating, the batter's walk grequency and the pictcher's durability factor at that stage of the game.

Wild Nolan Ryan might walk selective Joe Morgan 30 per cent of the time (dice numbers 1 to 30), while Mark Fidrych walks Mickeys Rivers only 1 per cent of the time.

Each subsequent throw of the ivories determines the percentage probability of a huge number of possibilities. Once in full swing, the UBLers can ask the dice to answer a dozen questions in rapid fashion: Where is the ball hit? How hard? Does the fielder have the range to reach it? Did the relay man bobble the throw? Did the baseman miss the tag?

Say there is an injury at the plate. Which man is hurt? Upper or lower body injury? How many days will he be out of league play? When he returns, how much will his efficiency increase will each additional day that he heals? Was it his power or his speed or both that was affected?

This is no game for kids, not even the most brilliant, but for adults who have at least 1,000 hours a year to spend "owning" a team.

Each club, right down to the Creighton Cruisers, has a 60-man roster, including a 'Tripple A team that also plays games. Teams draft minor leaguers so far in advance that when Garry Templeton of St. Louis broke onto the major league all-star scene this year, the Louisville Chargers of the UBL already had him protected in their system for three years.

The UBLers not only serve as owners, general managers and managers for their beloved teams, but also act as statisticians, historians, sports reporters and creators of elaborate mythology.

For instance, Ted Simmons, owned by the Nassau Bombers in the UBL, not only batted 318 in 121 games in 1976, but also grounded into 14 double plays, was hit by four pitches, was caught stealing twice, had 10 errors and five passed balls and walked 20 times. Oh, yes.He had only one sacrifice bunt.

Such statistics, from balks to bunts to picked-off-first, are kept for 960 players.

Every play in the 11-year history of the UBL is on record. Want to know who led the New York Sultans in batting in 1967? Carl Yastrzemski - 329.

But all this is just the tipe of the iceberg. Every months the UBL puts out a duplicate of The Sporting News with reports on every teams, feature stories and columns.

The "owners" are, of course, the sports writers, too, building up incredible, "histories" that continue from year to year, and now decade to decade.

The gentle, affectionate parodies of The Sporting News style are master-pieces. Listen to Blyleven explaining how he lost the fourth game of last year's UBL World Series to the accursed Bomber: "My fast ball wasn't there, and my curve, well you saw what Bonds did with it. Now I've got to listen to all that erap about how I can't win the big one. If we win the next two , I'll show everybody that I don't choke."

Raise goosebumps? It should. The verismilitude is frightening. The UBI's yearly guide and Sporting News imitations have pictures of the UBI players with their major league uniform insignias erased and UBL insignias in their place.

To read the thousands of words written about the Bomber-Blue Jay "fall spectacular" of 76, right down to the stirring dateline, "Oyster Bar, Nassau County, Oct. 10," is to believe that this thing happend.

"Don't expect me to say anything about champagne" said Bomber manager Gene Mauch after the fourth stunned Windsor by winning every big game they had to. They could still win three in a row and make me look like a fool."

UBL teams also get into brawls, and players are ejected or suspended.

Owners also have been known to feud with each other for years over shady trades or questionable use of a relief Pitcher. Just last night, Duncan, host of this year's all-star game, made one rival owner take his sleeping bag to the basement."Personality conflict, you'd say," he explained.

The feud arose in part because Duncan likes to play a recording of the game begins, set off fireworks after his team's homers, and bring in his relief pitcher's card in a tiny bullpen can painted in the Creighton Crusader colors.

Duncan even has a toy mule - "Roger W." - modeled after Charles Finley's "Charlie O." that sits next to him during play.

"I just did it for fun," said Duncan, "but I think it got on this guy's nerves."

The UBLers are naturally wary of appearing foolish, since they all are convinced that the world will never quite be ready for them.

After all, they have searched the country for years just to come up with 16 souls with the phenomenal patience and punctually needed to make a league that is run by mail operate smoothly.

"This is an utterly frivolous hobby," UBL commissioner Steve Lasley said proudly. "Our game is a hybrid . . . the final amalgamation of all the simulated baseball games that have been designed, plus 11 years of our refinements."

"We have fine-tuned our game to the point where it mirrors the major leagues down to the last percentages. That is to say, we've perfected it unitl it is completely useless and unmarketable."

In recent years, special UBL committees have been formed to investigate the higher mathematics of how they can correct minor flaws in their aggregate year-end league statistics: a few too many errors wild pitches, and a real stumper - why big-leaguers hit so many sacrifice flies.

Never fear, it took five years for UBl math whiz Mike Baran to produce a formula relating a pitcher's ability to pitch with and without men on base to his ERA. If Baran and his buddies beat that, what chance does a sacrifice fly here?

More touchy are the lengthy meetings at which the defensive range of every player in the majors is discussed.

Every UBL owner actually lives three different games of baseball and is fanatical about each. Since every player's "rating" card is based on the previous season's statistics. UBLers look at current box scores with next year in mind.

In other words, the Bomber manager who owns Rod Carew knows that he is going to have a phenomenally productive Carew card for the 1978 season.

As if worrying about both past and present were not enough, an owner must give his first priorities to the future.

"The key to this game is studying the minor leagues," said Duncan. "Everyone of us reads The Sporting News from back to front so we can study the A and AA leagues in the fine print first. You want to spot the next Willie Mays when he plays for Pulaski and draft him."

In such a world. it is not surprising that Duncan said. "We don't usually explain the game to our families, or to anybody really . . .

"Have you ever tried to tell your boss that you're taking a week's vacation to drive 1,000 miles to play a dozen face-to-face games against the Boise Barons?"

This weekend's combination all-star game and three-day "convention" is the hightlight of the UBL year.

"My mom once came to see the convention when it was held at our house," said the wife of the owner of the Cape Cod Hornets.

"One guy lost three straight games to the (awful) Wallingford Cubs and he ran into the backyard and dove into a swimming pool with only six inches of water in it.

"Another owner shredded the playing card of Steve Renko and burned it. He said he was going to put the ashes in an envelope and send them to Egypt, back to the owner in Cairo who had talked him into making the trade to get Renko.

"That's when my mother left, saying I never saw so many crazy people in my whole life." She didn't come back, though, so I guess it wasn't such a bad deal.

If the UBL sounds redolent of Kafkaesque fiction, it should. Nine years ago, novelist Robert Coover wrote a mordant, comic fable - "The Universal Baseball Association. Inc., J. Henry Waugh, PROP."

Coover assumed that Waugh - who wavered between fantasy and reality while spending the deep hours of the night playing a game in which every baseball play could be duplicated by a roll of the dice - was a flight of his imagination.

Little did Coover know that one Joe Sanchez, a political science professor at Adelphi University, had fathered the actual UBL two years before, establishing in reality a league that made Coover's wildly fictional oneman UBA seem elementary.

Far from being eccentric, the UBL owners are, in Lasley's words, "addicted game players . . . very orderly and realiable . . . attentive to details, especially administrative details.

Nevertheles, the range of UBL professions stretches from college professor to high school football coach, from music teacher to inspector general of the New York City housing authority.

Balanced against a salesman, an accountant and a recorder of deeds are owners with PhDs in psychology, history and geology.

Two owners in Rochester, Wash - Chris and Jeff Snell - are married. They played the famous "Bedroom World Series" of 1972. She won.

One owner devised a way to conduct last year's transcontinental minorleague draft involving 160 long-distance telephone negotiations for a total bill of $19.60.

Let it suffice to say that a typical phone call beginning. "Will you accept a collect call from Mr. Mark Fidrych of Oshkosh?" was a central ingredient.

But all day yesterday and last night the phone was off the hook. No disturbances.

"I doubt if I'll sleep tonight," said Tim Janicki, his pup tent standing in the yard. "I've got about 35 games scheduled this weekend and they take about 45 minutes each."

"We've been in the closet so long . . ." grinned Lasley. "We don't like to waste these days."

Janicki's daughter, Heather, her head barely as high as the game table, wandered through the room and watched the adults (average age 28.37) bent over their cards, calling out "60 . . . 72 . . . 39. Possible hit. What's the fielder's range? Diving stab. Pitcher's durability rating going down. Don't I hear a phone ringing in the Hornet bullpen?"

Heather knitted her forehead, then said decisively, "Silly."

The owners of the United Baseball League fell silent and looked at her for a nervous instant. Then they began to laugh. She would have plenty of time to learn.