Although no Washington-area schoolboy ever has attained a 50-foot triple jump, the Georgia state record is 51 feet 7 1/2 inches. These two facts exist because a young man who was going nowhere suddenly took off.

Nate Cooper, now the fourth best triple jumper in United States history, was a junior at Washington's Coolidge High in the spring of 1974, when he left home to attend Clarke-Central High in Athens, Ga. There he began the transition from a base-ball player of little note to a world-class athlete.

"I was halfway through my junior year at Coolidge and I wasn't doing that well in school," said Cooper, here for the National AAU Championships. "In fact, I wasn't doing much of anything. I had played two or three games of JV basketball as a sophomore, but I got appendicitis and missed the rest of the season. My junior year, I had a part-time job and I gave up sports.

"We had moved to Washington from Georgia in 1970 and one morning I just decided I wanted to go back to Georgia and graduate with my old friends. My mother tried to talk me out of it, but I went anyway, even though it didn't work out the way I planned.

"My sister was living in Athens and I had to go there, to Fran Tarkenton's old high school. I was a baseball fan and my dream was to be another Hank Aaron and play for the Atlanta Braves.

"But I moved to Georgia in the spring and the school had a good baseball team and I couldn't break the lineup. Track and field was not one of my favorite sports, but I did some running in gym class and started to play around with a few events. I didn't know anybody in town. It was just something to do.

"I tried the quarter and the hurdles, but the quarter hurt something awful the last 100 yards and I couldn't master the hurdles. The triple jump was the only thing I liked. I did 43-7 my first year, then I came back to D.C. for the summer and worked at the National Gallery of Art and thought about staying.

"I went back, though, and became all-Northeast Georgia in basketball. I got a couple of junior college scholarship offers, but I wanted to go to a big school and get my way paid, so I went back into track. I did 47-10 in a big meet in Atlanta, which was six or eight inches off the state record, but I sprained my ankle.

"It healed after a rest and I came to the state meet the end of May knowing it was do or die. I hit all my jumps over 49 and did 51-7 1/2 the first jump of the final."

Cooper went on to Villanova, where he won five IC4A championships in the last three years. It was not until June 2 in Champaign, III., however, that Cooper felt he fulfilled the promise of that big weekend in Georgia. On his final jump as a collegian, in the NCAA Championships, he leaped 56-1 1/4 to overcome Maryland's Dennis Ivory, boost his personal best by 19 3/4 inches and come within 5 1/2 inches of James Butts' American record.

"I'm still atonished by it," Cooper said. "I hope it wasn't a fluke. Even though I won five IC4As, most of my jumps were only mediocre to good until that 56-1. I want consistency at 55 or 56. In the triple jump, you can do 55 with the right momentum doing things wrong. To go 56 or 57, you have to do a lot of things right. It takes concentration. I know my flaws. I think I'll be out there again."

Butts, Ron Livers and Willie Banks are the favorites here, as well as the likely candidates for the 1980 U.S. Olympic team. Cooper, however, is conceding nothing.

"They've got more experience and it gives them an edge," Cooper said. "But I'm capable of winning. I definitely feel that if I can go 56, I'm always in the money until I've lost."

Ivory is here, too following his 53-3 personal best in the NCAA meet. Cooper credits Ivory for much of his success.

"Except for Dennis, I wouldn't have had any competition in the East the last couple of years," Cooper said.

"Dennis and I play a few mental games in competition, but when we go to the big meet it's always, 'Go get it, Dennis,' and, 'Go get it, Nate,'" Cooper said. "I wish next year I could come out here with Dennis and Paul Jordon to prepare for the Olympics.

"I think they're smart to do that. I'm going to play dumb and stay around Villanova. I'll work on the Nautilus machines and develop my strength. I might be missing some technical work, but I'll try to develop that on my own."

Cooper has done limited work since his NCAA victory, trying to retain his sharpness while treating a case of runner's knee. He sprained his left knee long jumping last summer, needed crutches for three weeks thereafter and has encountered recurrent symptoms during this campaign.

"It was better at Champaign (in the NCAA), after being black and blue at the IC4A," Cooper said. "This has been a trying year. I've had to curtail my training, train three days and then rest the knee. After that 56-1, though, I'm not going to complain."

He could, after all, still be walking the streets of Washington, not "doing much of anything."