The Gentleman of Paris roams streets of Havana in his flowing black gown and waist-length white hair.

In his wanderlings, he meets only kings and queens. Naturally, as befits a great man like himself, he expects to be invited to dinner by the royalty that he meets.

Each day the Gentleman of Paris eats at a different Havana home, always with kings and queens.

"No one can touch the Gentleman of Paris," says Manuel Gonzales, director of the Cuban Olympic Committee.

"Fidel has ordered that everyone be nice to him. The old fellow is incredibly intelligent, like the madmen painted by El Greco and the fools of Shakespeare. He can discuss anything with you. But he is totally insane."

"We say that he is the only person in Cuba after the revolution who does not work and play sports."

In Cuba, madness is the only acceptable reason for not participating in sports.

"The Gentleman of Paris is a symbol to us," says Gonzales, Cuba's undisputed patriarch of athletics. "He was driven mad before the revolution, so we cannot convince him of the rightness of our new ideas. Therefore, we humor him."

However, Castro's benighted madman is the only exception to a huge Cuban educational system of which athletics is an enormous part.

"Sport is the right of the people," is Castro's constant pronouncement. But sport is not only a right here, it is close to a duty.

Children are put in water at eight months of age to show them the first movements of swimming.

"We are very backward in swimming," says Gonzales. "This is a new program."

Cuban physiologists have been given the task of drawing up detailed descriptions of the prototypical body for all sports, so that children can be funneled into their ideal sport - and no other - at the earliest age.

"We can tell what sport a child is suited for at nine years of age," beams the ham-handed, cigar-smoking and cheerfully venerable Gonzales:

"Public education, public health and public athletics have been our greatest achievements," says Gonzales, stabbing the air. "And they are all interlocking."

"Sports are the greatest of all preventive medicines. We are struggling to build enough hospitals, to train enough doctors. Until we do, and even after, saying well is our biggest goal and athletics are the best pill."

Health is only one goal. Glory is another.

Cuba is well on its way to establishing a 6,000-student academy of sports in each of its 14 provinces where promising children are brought to work with the nation's best trainers, starting at age eight.

In all areas, Cuba is a strict meritocracy, basing advancement on constant testing, both educationally and athletically.

"People here are taught how to compete laughing, how to win and lose in style," says Gonzales expansively. "A sportsman looks at the world with a different face than other men and with a broader outlook."

Perhaps. But Cuba is also fascinated by results, as in gold medals, world champions, international notoriety.

"We were eighth in the world in the 1976 Olympics which is remarkable for a country with millions less people than New York City," points out Gonzales. "Our goal is to do better than eight in Moscow (1980). No specifices. But I promise we will meet that goal. We have no doubts."

Will Cuba someday approach the United States in the Olympics?

"Of course, that should be impossible," says Gonzales. "Yet America has had a bill before Congress for six years to help Olympic athletes and nothing has been done.

"America's whole Olympic organization is a disgrace. The world laughs at you. In Montreal, the States finished third (in total medals). If you are not careful, you will sink lower.

Cuba's Olympic strategy, its total sports philosophy is simple. "When we look at our children," says Ganzales, "we are searching for diamonds.

"Every child and every adult has a right to participate in athletics. And every diamond has a right to be discovered and polished."

The quintissential factory for this polishing is Havana's sports academy, the Martyrs of Barbardos School. It is the nation's model sports school with 2,000 students. 169 trainers and 70 academic teachers, a ratio Woody Hayes would envy.

"We stress emulation, not competition," says the academy's director, making the subtlest of distinctions. "There is a school in another province with which we compare the parameters o femulation of every child."

In other words, Cuba has gone beyond mere competition between schools. Each child is also measured, graphed, studied, coached against arbitrary performance standards that he is expected to meet.

When a student is accepted at the Martyrs of Barbados School (named after a youth bombing), not only his family, but his entire neighborhood, celebrates.

But standards for staying in the new academy are well defined. Step unannounced into the office of the seventh-grade fencing instructor and on his walls are both athletic and academic charts.

One shows every student's progress in a dozen fencing skills - week-by-week, whil the others show grades in math, Spanish, physics, chemistry, geography, biology and English. Cuba does not believe in creative writing, confrontation groups, relevancy and folk singing in its schools.

Simplicity and basics make the Barbados School hum on a typical afternoon. Each of 20 sports - all Olympic sports, except baseball, which merits being exception - has its own practice area. One child, one sport, year-round. That's the formula, although each boy or girl gets a taste of general physical education during part of each year.

If the academy sounds joyless, it isn't. Ten-year-old swimmers try to scramble past their instructors so they can dive off progressively higher and higher boards, right up to the terrifying high tower.

A table-tennis smash brings grins of delight in any land, and a red-haired boy, with a black eye from judo, has a right to sit in the corner and mope here, too.

"Our young people don't have time for marijuana in Cuba," says Gonzales, "prostitution, drugs . . . they are extremely hard to find. I would say impossible, because that is the case, but I know Americans cannot conceive of that.

"With work and study and play and, of course, romance," says Gonzales," who has time for vices?"

In many ways, the world of Cuban athletics is like a time machine with the switch set for a simple past. To fly from Mexico City to Havana with a prop plane full of members of the Cuban national rifle team is a flight back to the '50's.

The entire team is intent on a sort of restrained but single-mined rowdyism that includes beer, loud talk and laughter, ceaseless pinching and teasing of stewardesses.

The nonstop party seems on the verge of innocent control, like a bus full of football players who push the rules until somebody ends up sorry. But for Cuban athletes, the control never entirely disappears, even when it is invisable.

Seemingly the drunkest man on the plane is the coach. But when one rifleman ignores the "be seated" sign and keeps standing up during the landing, the coach barks for him to sit down, buckle up and shut up. The plane falls silent and the miscreant obeys quickly.

Although it is midnight at the Havana airport and the place is four hours late, the entire viewing deck is filled with 200 waiting fans, all silhouetted against the airport lights and all cheering and waving like mad. A Redskin welcome for a rifle team.

Most Cubans are what Americans might term "rubes" when the subject is sports. But these islanders would not choose to be sophisticated. For this land, whose boundaries are set by the sea, sports has become a kind of Cuban equivalent of 19th century American manifest Destiny. The Olympics are their visible evidence of national accomplishment and a rallying point for morale.

Critics of Castro's high-priority sports empire say that he puts stadium building ahead of apartment building, and that his innumerable new 20,000 to 60,000 seat ballparks are simply the cathedrals of a socialist society.

Free sports as the opiate of the people.

Certainly Cuban sports after the July revolution have a mythic, pioneer quality surrounding them.

As simple an object as a baseball is charged with political overtones. Every fan knows that the American embargo - always called "The Blockade" - forced Cuba to produce its own sports equipment (especially baseballs).

The first Cuban ball-winding machine, the local legend has it, was made from an old juke box and was set up in a vegetable garden run by a chinese family.

Each ball has the initials "L.P.V." stamped on it, standing for the Spanish exhortation "Ready to Win."

"Every time a fan throws a foul ball back into play so it can be used again, we are breaking the blockade," says Pinar del Rio star Juan Castro.

Nevertheless, even in Castro's Cuba the fingers that sew the stitches in the baseball, and the fingers that pitch it, come from vastly different segments of society.

Top Cuban baseball players dress unpretentiously and drive the same sort of ancient automobiles that have forces every Cuban to become a vehicular surgeon. But they are also educated, confident in their speech and far better-traveled than most major league players, since veterans of Cuba's national team have played throughout South America, Asia, India, Italy, Egypt, Russia and both Germanys.

The stitchers, sewers and ball-testers at the Havana sports equipment factory are typical of the mass of Cubans who still do the most monotonous labor. No mass production machine makes Cuban baseball bats. Each one is hand-tooled.

Above all else, the characteristics of Cuban sport are mass participation and mass interest - in everything from baseball and boxing through tennis and riflery.

Workers' leagues have large attendance. Cane cutters, even though the debilitating weeks of harvest, play doubleheaders on Saturday and Sunday in the baseball Sugar Cup.

From calisthenics for housewives, through reckless driving for everybody, Cuban society is permeated by games. "Solve the chess puzzle," blares the radio," and win 20 trips to the Soviet Union." Talk about your two-week prizes to Philadelphia!

Only the artistic impulse seems to rival the sporting one here.

Cuban aparement houses are awash in a dizzying rainbow of do-it-yourself colors. An unknown street artist paints a 400-square foot wall mural in a Havana alley. Any army guard, standing in a shed by the Plaza de la Revolucion during a rain storm, strums on his machine gun as though it were a guitar as he sings to himself.

But sport has become Cuba's greatest art. As language becomes politicized, perhaps poetry finds its release in action.

In the shadow of the National Hotel, a huge old rampart by Havana's ocean-walled harbor children play baseball until sundown, hitting their line drives into the midst of 50 m.p.h. evening traffic.

No one scolds them. Anyone who cannot get a '53 Studebaker to dodge a line drive is no Cuban driver. Or no sports lover. And that would be impossible.

All over Cuba, the games continue as the day ends. In Pinar del Rio, the fans of the upstart Vegueros cheer their baseball heroes in a curious Spanish adaptation of English idiom.

"You are no man of one deed," they tell the batter. "A cane between the gardners will clear the quadrangle. Bring your mates to the chocolate factory."

Over 300,000 Cubans watch this game of the day on TV, while more than 4 million others listen to announcer Sala Manca on radio telling them, "It's going. Goodbye my dear Lolita."

In proud, ancient Matanzas, the former Washington Senator pitcher Connie Marrero takes his seven grandchildren for a Creole dinner at a restaurant caled The Caves of the Beautiful Sea overlooking one of the most lovely inlets on this Isle of a Hundred Harbors.

"None of my three sons were athletes," says Marrero, now the Matanzas pitching instructor. "But perhaps in the second generation . . ."

In the mountain forests of remote Oriente province on the bluffs above the sea, Alberto Juantorena, the Olympic track champion is doing his 25 kilometers of daily training, using the natural grandeur of his island to break monotony.

"In every nation's history,' says Juantorena,' one generation is fortunate enough to live while a great song is being played. I am in that generation of Cubans. Sports is the melody of our revolution."

In a mango grove near El cano, the heavyweight boxing champion of two Olympics, Teofilo Stevenson, has finished his labors. He is gulping a seedy, red milkshake drink made from the mamey, an indigenous Cuban fruit.

One of Stevenson's trainers picks up a mamey and examines it like a professor.

"The mamey is our strangest fruit," he says. "It has a tough brownish skin on the outside, but has soft red meat like the avocado. The pit is huge and black. It takes the mamey 20 years to bear fruit."

In the 20th year of Cuba's revolution, this island's fruits are now ready for the harvest. Everywhere one looks, Cuba's athletes are ripe on the bough.