Bjorn Borg was about to take the stadium court to play his first match in the U.S. Open tennis championships on Wednesday, but Marty Devine wasn't interested.

He was perched comfortably in the bleachers of Court 16 at the National Tennis Center watching two teen-agers, Kathy Rinaldi and Kathy Horvath, smash ground strokes at one another.

Devine, who owns his own taxicab, had no interest in Borg. Or for that matter, CEnroe, Connors, Evert or Austin. Twice a year, dating back to 1965 when it still was a tournament for amateurs at Forest Hills, Marty Devine has come out to the first week of the U.S. championships, plunked down his money --- $10 a day this year --- and wandered the grounds looking for rising stars.

"I like to see kids before everyone knows about them," he said, huddling against the stiff breeze in a blue windbreaker. "I saw Evert here in '71 when she beat Eisel after being down, 5-1, and set in the second. This morning, I was watching this (Jimmy) Arias kid. Amazing, just 16."

Wednesday, Devine was focusing on Rinaldi. He had seen Horvath two years ago when she lost at age 14 on the grandstand court to Dianne Fromholtz. "Rinaldi's goint to be better than Horvath," he said. "She's stronger, Look at how hard she hits the ball already."

Horvath won this day, but Devine wasn't disturbed. "It just means next year I'll get to see her win her first match. It'll mean more to her that way."

He smiled. Kakthy Rinaldi was this year's discovery.

In the daytime, among the patrons at the U.S. Open are some genuine tennis fanatics, people who take vacation days off from work to come out and watch.

At night, the crowd is decidedly different. Coats and ties, designer dresses and jeans abound. The outside courts aren't used to night, but if they were, most of the night fans would not venture that way. Too long a walk. The night crowd just wants to see the names, even if their early matches are romps.

During the middle afternoon hours the tournament takes on the atmosphere of a state fair. No one sits still long for long, moving from court to court, constantly seeking the most competitive match.

For the players, the nomadic quality of the crowd is an endless nuisance, especially on the outside courts where any movement in the bleachers is easily detectable. Time and again players are foreced to wait to resume after a court change because the crowd hasn't settled.

The United States Tennis Association has tried hard to create some of the grassy, almost country atmosphere of Forest Hills here, but it is impossible.

Start with loctions. To reach the tennis center, it is necessary to cross a wooden bridge that leads from the parking areas and the subway stop to the "grounds."

The walk on the bridge shows frequent signs of decay and grime, trademarks of many parts of this city. To the right are battered, unused subway trains, No. 7s built in 1964 for the World's Fair and the opening of Shea Stadium. They were spanking new then, but now they sit, filthy, creaky and in disrepair.

To the left is Flushing. And it's hardly a Meadow. As the tennis center comes into view, so do the old World's Fair gounds, now virltually deserted. The old New York State exhibit, burnt out and filthy, towers over everything.

The atmosphere inside the fences is decidedly different from any other major event in the world. To get to any court from the locker room, the players must mingle with the paying public.

For players used to constant pampering and protection from the bordes, this can be a shock. The superstars still have their limousines, the less-than-superstars courtest cars. The Borgs stay at their new home in Sands Point. The Connors have an apartment in New York. The Lloyds move from hotel to hotel so they won't be tracked down.

This is an autograph seeker's heaven. One couple comes every year, but never watch a match. They stand outside the clubhouse, snapping pictures. The next day they return with the developed photos and get them signed by the players.

Security is everywhere, omnipresent. As Martina Navratilova puts it: "You have to go through six security checks here just to get into the parking lot."

And that's if you're a player.

Celebrities abound, but hardly anyone notices unless they wield a racket.

Comedian Alan King walks each day from the stadium to the grandstand and back almost unnoticed. Friday, as Evert walked to her limousine, parked right outside the gate, she stopped frequently to sign autographs. Right behind her was Linda (Wonder Woman) Carter. No one asked for her autograph.

This isn't Winbledon and no one pretends it is. At Wimbledon, you'll never see a match delayed because of a praying mantis or a bat landing on the court. At Wimbledon, you never will have a match stopped because of acrid smoke from a trash dumpster fire filling the grandstand court. This caused Ivan Lendl to almost stop breathing; he left the court in a huff --- to boos, of course.