They occur in every baseball generation, the uncut diamonds from which melancholy legends are made. In 1954 there was 23-year-old Karl Spooner (summoned to the Brooklyn Dodgers in September), who in two nerveless performances near the end of a pennant race struck out 27 batters and allowed not a run. The following season he won only eight games and soon was gone. Some 20 years later came the Detroit Tigers' Mark "The Bird" Fidrych, 21, fidgeting on the mound, muttering to the ball and blowing away hitters with a joy that filled stadiums. He won 19 games that first year, six the next, then ruined his arm and fell to the minors.

Surely no one would wish the same fate for the Los Angeles Dodgers' Fernando Valenzuela—not even the frustrated National League hitters who have been so thoroughly stifled by the cheerful Mexican left-hander in the stunning first weeks of this season. Valenzuela, 20, has been pitching like a creature from some other planet. Not only did he win his first six games (four without allowing a run), but he struck out 50 batters and walked only 11. Adding the statistics he compiled in several appearances as a relief pitcher at the end of last season, Valenzuela's earned run average for the first 71 2/3 innings of his major league career was an untouchable 0.25. That's roughly comparable to batting .900. Marvels Dodger manager Tommy Lasorda: "Nobody's ever seen anyone break in with this kind of a bang. I've run out of words to describe him." Others, however, caution that Fernando's sternest test will come later, when he has to face the same teams he beat the first time around. "I want to see him again," grumbled Montreal Expo catcher Gary Carter. "He's obviously very good, but you measure greatness over years, not weeks." Valenzuela knows that the bubble must eventually burst. "No one can continue winning like this," he says philosophically. "You have to lose, and not just once."

The youngest of 12 children, Valenzuela grew up in the northwestern Mexican village of Etchohuaquila (pop. 150), where his father grew beans and corn on a half acre. "My brother Rafael was the first one who told me I could play baseball professionally," he says. "He had played pro ball himself, so he knew. He gave me confidence." By the time he was 16, Fernando was pitching in Mexico's minor leagues for $80 a month. "I didn't get much chance to play," he recalls. "I was always told I was too young, and I was very lonesome for home. I wanted to be with my parents and my brothers and sisters, but I said to myself, 'If you want a baseball career, put up with it.' " Two years later he was discovered by Dodger scout Mike Brito, who bought his contract from the club that owned him for $120,000.

It was a blue-chip investment. Last month, when Dodger veteran Jerry Reuss couldn't pitch the season opener because of an injury, Lasorda called on Fernando—and the legend was born. Although he throws a variety of pitches with effortless control and changes of speed, Valenzuela credits his success to his screwball, a kind of reverse curve that leaves most batters baffled. "He learned the pitch so damn fast," says Dodger relief pitcher Bobby Castillo, who taught it to Valenzuela soon after he joined a Dodger farm team in 1979. "Some guys spend years, but he got it right away." Perhaps the highest praise comes from Hall of Famer Carl Hubbell, who trademarked the pitch more than 50 years ago. "He's the only pitcher I've seen in 40 years who can throw it," says Hubbell, 77. "He's got the best screwball since mine."

Valenzuela's sensational start has made him an instant hero in Los Angeles, especially among the area's two million Hispanics. One newspaper ran a contest to nickname Fernando (the people's choice: "El Toro"), and team officials have estimated that Valenzuela could draw an additional 15,000 fans to Dodger Stadium every time he is scheduled to pitch. Yet despite his fame (and the fortune to come), Valenzuela today earns $42,500, just $10,000 above the major leagues' minimum salary. He lives modestly in a motel just five minutes from Dodger Stadium, has no steady girlfriend and, since he doesn't drive, depends on friends to provide transportation. When it comes to feeding his 5'11", 190-pound frame, however, Fernando is capable of looking out for himself. "Steaks, salads, avocados, Mexican food, carne asada, beans, rice—I do like to eat," he declares.

Still, his chubbiness hasn't hindered Fernando, and his friends' only concern these days is whether he can live up to his billing as Superman. "We still call him 'Muchacho,' " says an old Mexican minor league teammate, Severiano Talamante. "I worry about him being so young and so shy. He felt very alone last year on the Dodgers. But now they're giving him a kind word, a pat on the back. He needs that." As for Valenzuela's ability, adds Talamante, "That's the only thing I don't worry about. Give him a bat and he'll hit the ball. Give him a ball and he'll strike somebody out. He's just special."