It's a little like the Hatfields and the McCoys; no one knows how it all started, and it's too late to stop now.

Some place the blame on Willem DeKooning and Franz Kline, while others point to the arrest of artist Robert Gwarthmey for flying a peace flag at his house in 1971. A third school puts the onus on the nyriad softball assemblages that have accompanied Sunday-morning hangovers in the Hamptons since John Foster Dulles was secretary of state.

Announcer Monty Farber made his own calculations Saturday afternoon and simply said, "Welcome to either the 21st or 25th annual Artists-Writers Softball Game."

Several notables like Willie Morris and George Plimpton didn't make it this year. But Peter Maas, Anthony Lucas, Carl Bernstein, Ken Auletta, Judy Klemesrud and James Lipton, among others, donned the writers T-shirts and slugged it out with the artists, who were led by Time art director Walter Bernard and art dealer Ben Heller.

"I've been avoiding this for the past four summers, but I concluded that the boycott should end," explained Lucas. "I'm available to strike out."

To his astonishment, Lucas got on base. The writers' juggernaut mobilized once again and, depending on whom you talk to, triumphed either by 11 to 8 or 13 to 8.

"It was 11 to 8," writer-manager David Pearce stated flatly. "It was 13 to 8," countered Elaine Benson, manager of the artists. "What do you know; you're an ophthalmologist;"

"Well, you're a gallery owner, my dear," Pearce replied.

In truth, the artists have generally suffered the same fate as the Yale Daily News against the Harvard Crimson, which officially records their annual touch football game as a 22 to 3 Crimson victory each year, regardless of what happens on the field.

The only artist victory in memory occurred two years ago, when the crafty Benson imported two women who are professional softball players for the Connecticut Falcons. One was a pitcher who made mayhem with the fragile writers' egos and won the game handily.

But other than that, times have been hard for the artists. Herman Cherry, an artist-player emeritus, explained why.

"The writers are well fed. They live in beautiful houses. They have beautiful broads. They're all out jogging every morning - what do you want?"

"We haven't won a lot," Benson conceded. "But we're very democratic. Everybody plays." Pause. "Also, we don't practice."

Cherry is perhpas best known around the softball diamond for his creative use of a grapefruit a few years ago. He painted one white and arranged for it to be pitched to George Plimpton, well-known for his sense of humor and his athletic enthusiasm. But Plimpton's humor reportedly exploded along with the grapefruit when he stroked it with crisp authority, showering himself with gobs of vitamin C.

Lipton, who produces all of Bob Hope's specials, made it clear that the artists-writers game is the father of all of the softball mongrels that new dot the Hamptons and the rest of the world.

"First there was us," he said. "Then there was the one in Beverly Hills, then Hyde Park in London, and finally the Parvenus in the Bois de Bologne.

"It's like a religion to us," he explained. "We're all growing old in the service of this game."

A stranger has every right to be dumbfounded by the arcane subdivisions within the softball structure in the Hamptons, let alone the Bois de Bologne.

First, like the monolith in Stanley Kubrick's "2001," there was the East Hampton early morning game, which attracted anyone who could focus at that time of day. Then, in the dawn of civilization, Willie Morris formed his own team, the Nematids, named for the potato bug because they played in the potato fields in nearby Bridgehampton.

Most recently, the Sag Harbor team has gained some recognition, due largely to its contingent of young journalists like Bernstein, Auletta and Klemesrud.

"Parvenus," sanpped Lipton about Sag Harbor. Also well said. But they take their game so seriously that women like Nora Ephron, Bernstein's wife, lose their husbands for most of every weekend.

It would appear, in fact, that the game has replaced the cocktail party in the Hamptons. "It is the cocktail party," Ephron said as she watched her husband work behind the plate.

But the artist-writers game had the tradition that transcends the athletics, which may be a blessing. While artists like DeKooning and Kline and numerous writers did play informally for years, it was artist Gwathmey's celebrated arrest in 1971 for flying a peace flag, like Alice's Restarurant, that put the game on the map.

One political act deserved another, it was felt, and the teams played their game that year to raise money to wards Gwathmey's court costs. Gwathmey won, and the game has been a fund-raising event ever since.

People paid in 1972 to raise funds for George McGovern. (Gene McCarthy, in his status as a poet, played as a writer for a number of years but never benefited from it as a presidential candidate.)

Admission money also went to the Head Start program in Easthamption during the years that Richard Nixon tried to dismatle the Office of Equal Opportunity. This year's purse went to the local day-care centers.

As alwyas, the crowd rooted for the beleaguered artists. Saturday's game was particularly cruel for them, because they actually led by two runs during the fifth inning.

Writer-manager Pearce displayed great sang-froid at the time. "I have no idea what the score is," he said when asked. "Are you kidding?"

His players knew what was going on, though, and soon regained their form, Bernstein, who was called out looking in the first inning, began hitting. Auletta continued to stroke the long balls, and Maas delighted everyone with his play at first base and his concern for the fine points of the game.

"Should I wear my watch this year, David?" he asked Pearce as he warmed up.

If the weather was bad Saturday, the crowd was blessed with the remarkable announcing talent of Farber, an aspiring song-and-dance man. Farber was positioned so far from the diamond that he rarely had any idea what was going on or who was batting.

"Did something just happen?" he would ask the crowd over the antediluvian public address system he had brought with him. He finally gave up on names and introduced people like "Roger Maris."

"It's like instrument flying," he explained.

Late in the game - the outcome no longer in doubt, the beer flowing freely, near anarchy on the field - Farber whispered into the microphone, "You can cut the tension with a knife." CAPTION: Picture 1, Author Peter Maas rounds first for the writers' team, by Donal F. Holway; Picture 2, The winning writers' team, by Donal F. Holway for The Washington Post