Early last fall, at a time when realistic trainers of 2-year-olds don't even permit themselves to dream about the Kentucky Derby, Snow Chief was beginning to display the stamina and professionalism that would make him the star of his generation.

As Snow Chief ran impressively in stakes races on the West Coast, he twice faced a colt named Badger Land and trounced him both times. No one could have imagined that when Snow Chief came to Churchill Downs in pursuit of roses and glory, his greatest obstacle would be Badger Land.

Yet these two colts from California are the standouts in the 16-horse field that will contest the 112th Derby on Saturday. The contrasting ways in which they developed into prime contenders vividly illustrate the unpredictability of the game.

Although he has a horrible pedigree and was figured to be a cheap claiming horse, Snow Chief was a natural athlete from the start of his career. Although Derby favorites are often the targets of sniping at Churchill Downs, Snow Chief is the kind of horse horsemen love.

Laz Barrera, who trained Triple Crown winner Affirmed, offered this appreciation: "He's a professional. He's won going long, he's won going short. He's won on fast tracks, he's won in the mud. He travels. He was a hell of a horse before they put blinkers on. He's a better horse after they put blinkers on. How you going to beat him?"

Few rivals have found a way. By the end of last season, Snow Chief had become the first millionaire 2-year-old in history. This year he has raced four times and won four times -- decisively. When he worked three-eighths of a mile in 34 1/5 seconds this morning, people who have watched the colt all spring concurred that he was sharper than ever.

If Snow Chief was a natural, Badger Land was the antithesis. "If he was a basketball player," trainer Wayne Lukas said this morning, "he'd be Manute Bol. He was gangly, he was slab-sided, he made a lot of mistakes. But every day I saw him grow and get a little bit better, and I said this winter that if he stayed sound he'd be an important horse by July."

Badger Land exceeded even Lukas' expectations. After running a strong second to Snow Chief in the Florida Derby, he won the Everglades and Flamingo Stakes at Hialeah, running 1 1/8 miles in 1:46 1/5 and 1:47. In the view of people who handicap horses according to speed, Badger Land is a better horse than Snow Chief now.

Lukas concurs. "This is the most improved horse I've ever trained." After years of frustration at Churchill Downs, the Eclipse Award-winning trainer thinks he has his best chance ever to win the Derby. But he knows he has one tough foe in his way.

If Badger Land is Manute Bol, a reporter asked Lukas, then who is Snow Chief?

"Danny Ainge. He'll play you belly-to-belly and do everything he can to beat you."

Bettors at Churchill Downs, as well as those at 57 simulcast locations around the country (including Pimlico), are likely to wager on the Derby as if it were a virtual two-horse race. Snow Chief is expected to be favored at about 6 to 5, with Badger Land at 5 to 2 or less. Everybody else in the field should be 10 to 1 or more.

However, the rest of the lineup does include horses capable of pulling an upset. And it includes some fascinating ones who could make the 112th Derby a historic one with a victory.

*Bold Arrangement fits into both categories. Trainer Clive Brittain brought the 3-year-old here from England with the lofty aim of trying to win both the Kentucky Derby and the Epsom Derby. It seemed to be a preposterous idea -- until Bold Arrangement prepped for the Kentucky Derby with a come-from-behind third-place finish in the Blue Grass Stakes last week.

Horses from abroad sometimes run well their first time in this country and then go off form, so Bold Arrangement is still a mystery horse. But if he wins he probably will change the face of international racing.

*Ferdinand is surely the sentimental favorite because of the presence of 54-year-old Bill Shoemaker on his back. But the support for him is due more to his 73-year-old trainer, Charles Whittingham. The great West Coast horseman has a well-known antipathy to the Derby -- he hasn't sent a horse here in 26 years -- but he has been talking about the regally bred Ferdinand for months as a legitimate Derby horse. "Maybe when you get old you get foolish," Whittingham said, but this Hall of Fame trainer is nobody's fool.

*Fobby Forbes, in the view of the racing establishment, is the very antithesis of a sentimental favorite. He is owned by Robert Brennan, the maverick who disrupted last year's Triple Crown series by luring Spend a Buck to the Jersey Derby at his track, Garden State Park. He would love to leave the Preakness without the Kentucky Derby winner for the second straight year.

*Rampage is probably the least-publicized of the legitimate Derby contenders, since he has spent the whole spring at Oaklawn Park, where he won the Arkansas Derby. But he has all the proper credentials for a Kentucky Derby horse: the seasoning, the pedigree, the stretch-running style and a top jockey in Pat Day.

Other legitimate contenders include Maryland colt Broad Brush, the upset winner of the Wood Memorial Stakes at Aqueduct in his last start; Mogambo, who is trained by two-time Derby winner Leroy Jolley, and Vernon Castle, a lightly raced colt who dazzled Californians with impressive victories in his only two starts as a 3-year-old.

But if Snow Chief and Badger Land are upset Saturday, it will probably not happen because one of their rivals turns out to have more talent, but because of the way the Derby is run. Pace and racing luck frequently determine the winner here.

This field is filled with speed horses, and most of them have drawn outside posts, which will force their jockeys to gun from the gate to get position. Groovy, in particular, seems certain to set a hot pace. He was practically uncontrollable in a workout here, and trainer Howard Crowell acknowledged, "I think we have to outrun every other horse."

Both Snow Chief and Badger Land are endowed with some speed. Their jockeys, Alex Solis and Jorge Velasquez, will have to use it judiciously. If they get hooked up in a premature battle for the early lead, they could set up the Derby for one of the stretch-runners: Rampage, Ferdinand or Bold Arrangement.

But if the race develops in a reasonably normal fashion, it is likely to come down to a rematch between the natural athlete and the late bloomer who had their first meeting in Del Mar, Calif., last September. This time, however, the outcome may be different.