There are success stories in baseball and then there's Bryan Clark.

For five amazin' years, Clark was the worst pitcher in all of organized baseball. You can look it up.

Even his cumulative record--14-52--gives only a hint of how awful he was. In five years, all in lowly Class A, he pitched 508 innings; he allowed 473 hits and walked 484. Counting hit batsmen (and there were many) more than a thousand runners reached base against Clark and 410 of them scored.

Clark, who gave fresh meaning to the expression "wild young southpaw," led four leagues in wild pitches, two of them in the same season. Mostly, Clark threw balls. Even when he got the ball in the strike zone, that worked out badly, too.

In fact, during those years, Clark may have been the worst pitcher in the history of baseball. Who else was ever given the opportunity to be so bad for so long at so rock-bottom a level?

Now, at 26, Clark is a pitcher with a storybook future.

After a last-chance transformation four years ago in a season with the Alexandria Dukes, Clark's career has gone from the ridiculous to the sublime. Now in his third successful major league season, he may even be a late-blossoming star.

Last season, in 115 innings with the Seattle Mariners, his ERA was 2.75. This season, he's doing better, with a 2.18 mark after 33 innings. The Mariners are thinking about moving him into their rotation.

This weekend when Seattle plays in Oakland, more than 200 friends and California relatives will be in the park each day on passes from Clark.

"I'm hard on 'em in Oakland. I get 'em all the time," grins Clark. "Last year, my uncles would say, 'Billy Ball's gonna wear you out,' but I told them, 'You'll see what I do to Billy Ball.' It's just like the Yankees and the Tigers. They can't handle me, either. My friends are going to be proud of me when they see me, 'cause I always pitch well for them. I always knew I'd get here."

Who believed in Clark, prodded him, inspired him in those miserable years?

"Me," he says.

Clark, a 6-foot-2 185-pounder from Madera, Calif., near Fresno, was an inconspicuous 10th-round draft choice in 1974. The Pittsburgh Pirates sent the cheerful teen-ager with the tolerably promising fast ball to Bradenton in the Gulf Coast League. There, he led the league in walks.

In '75, Clark went 7-17, walking 138 in 131 innings. In '76, Clark was 1-13 while allowing 201 men on base in 103 innings, with 31 wild pitches. With Salem in the Carolina League in '77, Clark was nailed for 135 hits and 104 walks in 125 innings. He allowed 7.56 runs per nine innings and, of course, led the league in losses.

In '78, Clark pitched 87 innings. His totals: 89 hits, 97 walks, 86 runs allowed and a 1-10 record. In his last stop, at Stockton, Clark pitched the equivalent of three full games--and allowed 39 walks, 30 hits and 32 runs.

Catchers refused to play when he pitched. "They were scared of me, because I beat 'em up something awful," he says now. "Broken fingers. Bruises . . . one of them at Charleston just came right out and said, 'I won't catch him.'

"Umpires gave me funny looks, 'cause I could hit them all over the feet and legs, too. Man, they didn't give me any breaks, either, 'cause they were glad when the managers came to take me out of the games."

It would be convenient if Clark had a simple explanation for why he didn't quit and why, suddenly, in 1979 with Alexandria, he became a 14-5 pitcher with a 2.64 ERA. But he doesn't. Reality isn't convenient.

Clark's parents implored him to quit and let them pay his way through college. "My wife didn't want me to play anymore, either. She never really believed I'd make it." The Pirates gave up and traded him--as the "player to be named later"--in an invisible deal in 1978.

In the end, Clark ignored all the advice. Instead, he listened to his heart.

"I used to go home and cry to myself . . . If you have any heart inside, you get tired of hearing people talk about how wild you are and how you'll never make it. But I never lost my confidence. I'd seen guys in the majors with less stuff than I had," says Clark, whose best fast ball has been clocked at 89 mph--good, but hardly exceptional.

In Alexandria in '79, two people helped get Clark straightened out. First came Mariner organization pitching coach Mel Stottlemyre, former Yankee star.

Stop trying too hard. Relax and be smooth, Stottlemyre told Clark. Others had said the same, "But I could never get it through my head," says Clark. One phrase in particular impressed Clark: "Strikes are money."

More important than Stottlemyre, however, was Dukes coach Mickey Bowers, an earthy, fun-loving bear of a man.

"Mickey Bowers kept pushing me. No matter what I did, even if I only gave up two runs and struck out nine, he'd scream on me. 'That ain't good enough. That's not going to get you to the majors. I was like you once--hard-headed. I didn't set my goals high enough. That's why I never made it. I'm not going to let it happen to you.'

"Sometimes I almost wanted to fight him. But I realized that when he was in uniform, he was going to act like a jerk, for my own good. But when he didn't have his uniform on, he was my friend. I started driving myself as hard as he drove me."

Even now, the bad old days are still too fresh. Clark has days, like this week in Memorial Stadium, when the first pitch he throws gets hit over the center-field fence and he walks five in two innings and can't say why. But, each year, he's learning to think fresh thoughts, and aim higher.

Ask him what the future holds and Clark has to think a minute. "I feel," he says deliberately, "that I could be one of the best left-handed pitchers in the American League."

That's a fancy goal for a little-known long reliever in the Seattle Mariner bullpen. But then, no one but Bryan Clark ever thought he'd get that far.