In the last day I spent in California this winter, I ran into Wayne Lukas, exchanged a few pleasantries and said goodbye. The trainer responded, "I'll see you in the spring."

I looked at him quizzically.

"At the Derby," he said.

Now I looked at him with disbelief. With the Kentucky Derby less than two months away, not a single 3-year-old in his barn had shown any special ability.

"I'll probably be there with Marfa, and maybe a couple of others," Lukas said.

I could hardly wait to get to the press box and tell my pals that Wayne Lukas had lost his mind. We shared a few laughs over the preposterous idea that Marfa--who had won one maiden race in seven career starts--might even be a marginal Kentucky Derby candidate.

Obviously, Lukas is a man who believes in the power of positive thinking. And, evidently, the positive thinking works. Marfa is the favorite to win the 109th running of the Derby, and he is only one member of a three-horse entry that Lukas will saddle Saturday.

Rarely has a trainer experienced such drastic swings of fortune as Lukas has in the past few months. When Landaluce, his brilliant and unbeaten filly, died after a viral infection in November, he was shattered, and his stable abruptly stopped winning races. Ordinarily an intense worker, he was just going through the motions.

"It took us a while to get over the shock of losing that horse," he said. "The atmosphere went through the barn. But I know how to get out of a slump. When I was coaching basketball, I'd keep the guys on the court a little longer, have them put in more practice time. A baseball hitter in a slump doesn't hang his head; he gets in the batting cage."

After a 2 1/2-month slump, Lukas' horses suddenly started coming to life in March. One of his seemingly mediocre 3-year-olds, Balboa Native, won the $200,000 Louisiana Derby. But none of his horses underwent such an amazing transformation as Marfa.

The son of Foolish Pleasure never looked like a potential star in the first few races of his career, but Lukas refused to give up on him. "You've got to keep the faith," he said. "Some horses are slow to develop--just like human athletes--and you've got to keep believing they're good horses . . ."

Lukas was never quite sure how Marfa would wind up. "One day," the trainer said, "he'd work and I'd ask the rider to pick it up and he'd go the last quarter in :11 4/5. I'd say, 'This is a damned good horse!' The next day, I'd say, 'He's cheap'. But by March, we'd really zeroed in on him."

After winning only one of the first eight races of his career, Marfa finally lived up to Lukas' most optimistic expectations when he won the Jim Beam Spiral Stakes at Latonia by eight lengths. Next, he won the prestigious Santa Anita Derby.

Last Thursday, he should have won the Blue Grass Stakes at Keeneland, but bore in so badly during the stretch run that he finished second and was placed fourth for interference.

Still, he showed so much ability that he cemented his status as the Derby favorite, and proved that Wayne Lukas may not be quite so crazy as some detractors in California had thought.