Inevitably, as a racehorse becomes famous, everything about him improves.

His pedigree, in particular, is found to be carrying bluer blood. His conformation gradually loses its faults. And his public image is embroidered by stories recalling how special he was from the day he was born.

One notable exception to this trend was Secretariat, who was a star from the day he left Meadow Stud.

Howard Gentry, the manager of the Doswell, Va. farm wrote early in 1972 about Secretariat: "Best horse we've raised here."

Now there is Seattle Slew, following in Secretariat's Triple Crown footsteps. But wait. Seattle Slew's people still haven't learned how to play the image game.

"When he first arrived with three other horses at the farm in Maryland from Kentucky in late September he had his really big body and this great big, rounded head, and this little foal's tail with all the short hairs," Paula Turner recalled this morning. "There was a big piece of him here; a big piece there, but it sure wasn't altogether. And his mind hadn't caught up with this body. He wasn't stupid. He was just a kid.

"We looked at him," the trainer's wife added, "and he looked like a big duck, so we called him Huey, or Baby Huey."

Seattle Slew was purchased for $17,500 at a kentucky yearing sale in July of 1975. The Bold Reasoning colt stayed in the Blue Grass country near Lexington until the time came for his early education and training by Turner on a farm near Monkton, Md.

"He was very slow coming around," she said. "It took him maybe three times as long to learn things but once he started getting it together everything fell in place quickly. I put a mouth (getting him used to a bridle and bit) on him, got him up to jogging between 2 to 3 miles a day and cantered him only enough so he'd know how to change leads properly. He was still rough about it when he left for the race track at Belmont in May.

"But he had started to impress me by then. I remember calling Billy up one day at Belmont, after I'd ridden Huey all around this big 65-acre field we had there, and I told him this colt was the most business-like young horse I'd ever been on. He had become serious about his running. He wasn't goofing off anymore."

Seattle Slew seems capable of actually measuring his competition during a race. Or, as Frank Tours of the New York Racing Association observed before the Kentucky Derby: "This horse is a fighter. If you put all the horses out here in a fight, Seattle Slew would win . . . And I think all the other horses know it."

Such a thoroughbred has license to be the 10th winner of the American Triple Crown. The fact that he should be the first such winner to be undefeated only adds to the spirit of the occasion.