In 1976, he was drafted by the Cubs and brought to the big club the next year. Chicago needed relievers to help stem the home-run derbies at Wrigley, and Hernandez was thrown into the fray without having a chance to learn his craft. "Wrigley, you spit and it goes out of the park," says Hernandez.
In February of 1983, former Baltimore pitcher Mike Cuellar, a master of the scroogie, taught Hernandez how to throw the screwball in the Puerto Rican League. "I was hanging my changeup, and he told me the screwball was a better pitch," says Hernandez. "I watched and said, 'That's true.' " Then, in spring training with the Cubs, Hernandez learned how to deliver a cut fastball from Ferguson Jenkins. "All of a sudden, I could pitch inside," says Hernandez.
Still, Hernandez was loath to use the screwball until he was traded from Chicago to Philadelphia in May. "[Catcher] Bo Diaz loved that pitch, he just called it and called it," says Hernandez, the excitement of the discovery still fresh. "Oh, I was taking out a lot of guys with that pitch. It was unbelievable." Six of those takeouts came when Hernandez tied the National League consecutive strikeout record, against the Mets.
Hernandez has been so good this year that he has overshadowed Lopez, who was the Tigers' main short-relief man last year. "Everyone in baseball is fallible," Lopez says. "The trouble is, Willie has been infallible. That's scary."