Barry Irwin sometimes used to make the business of syndicating thoroughbreds look easy. He and a partner would spot a racehorse with the potential to improve, buy the animal, sell shares to investors. They often won stakes races this way, and almost won the Kentucky Derby and the Preakness.

The game was spoiled when too many people got into it. Sheikhs and tycoons started looking for the same types of horses that Irwin was seeking, and they were driving up the prices. Irwin had to find more creative ways to obtain racing prospects for the syndicates formed by his company, Team Valor International. One example: He bought a 4-year-old filly at an auction in Germany, brought her to the United States, where she flopped as a racehorse, bred her to an unfashionable stallion, syndicated the foal — and won the Kentucky Derby.

That is the story of Animal Kingdom, who will try to win the second leg of the Triple Crown on Saturday at Pimlico. The Derby was not only a triumph for Irwin but for the concept of syndicating racehorses that he has championed since the 1980s. Twenty investors shared the rare joy of winning America’s greatest horse race.

Irwin, formerly a writer for the Daily Racing Form, started this venture with press-box colleague Jeff Siegel — once of the country’s sharpest handicappers —with the idea of “trying to find horses with hidden form that we could improve.”

They bought Captain Bodgit on the basis of some promising speed figures, and in 1997 he finished second in the Derby and third in the Preakness. They bought Martial Law, a colt who had been performing poorly at minor tracks in England because his pedigree suggested he would be much more effective on dirt than on grass. When they brought him to the United States and put him on dirt, Irwin recalled, “we knew we had hit the mother lode.” Martial Law won the $1 million Santa Anita Handicap at odds of 50 to 1.

But after a multitude of agents started trying to buy promising racehorses, paying sky-high prices for horses such as Captain Bodgit, Irwin reinvented his business. He bought out his partner. He concluded that breeding horses might be a better gamble than buying racehorses. And he decided that other countries offered better buying opportunities than the United States.

His business works this way: If Irwin buys a horse for $100,000, he marks up the price, typically around 30 percent. He sends information about the horse to his roster of clients and invites them to take a percentage of the $130,000 sale price. People who join the syndicate get billed for their prorated share of training expenses, typically $50,000 a year per horse. The company receives a 10 percent share of any net profits as well as a 5 percent commission when a horse is sold.

The vast majority of racehorses in the United States lose money, and the arithmetic of horse ownership is even more daunting when the owner has to pay extra fees and markups to a manager. But Irwin’s approach to the business allows his clients to make horse investments that they could never undertake on their own.

Irwin appended the “International” to Team Valor’s name when he concluded that some of the best opportunities for buying horses lay in South Africa and Germany. His syndicates own 16 racehorses in South Africa, and some of the partners regularly take junkets to watch their horses run.

Almost all of Team Valor’s mares have international backgrounds. In Germany and South Africa, Irwin said, “you can’t use any drugs and you have bigger, stronger and better horses.” Because of his respect for German bloodlines, he spent $400,000 for the filly Dalicia, who possessed a high-class pedigree and had won a Grade III stakes in which she had beaten Germany’s horse of the year.

“For that money, I could never have gotten anything like her in the U.S.,” Irwin said. When Dalicia had her first foal, he offered shares to people who had invested in the mare, and that was the genesis of the Animal Kingdom partnership.

Irwin complains that the racing industry does not always treat such partnerships with proper consideration.

“There’s a real prejudice against larger ownership groups,” he said. “Sometimes they minimize people because they can’t afford to buy the whole horse.”

Such a characterization doesn’t apply to the Animal Kingdom syndicate, most of whose members are well-to-do businessmen, active or retired. Bruce Zoldan is the CEO of the Youngstown Phantoms in the U. S. Hockey League. Ed Weil of Winnetka, Ill., 83, was the owner of a telecom-equipment business. Carl Pascarella of San Francisco, who runs a private equity firm, was chairman of Visa USA when the credit-card company sponsored the Triple Crown series. Tom Furey of Madison, Conn., is a retired IBM executive who oversaw the company’s technology at the Olympic Games.

Furey raced harness horses in his own name for many years, but he was attracted to the syndicate because he wanted the experience of “racing at the highest level of the game.” He thought he had reached the apex when he went to Hong Kong to watch a Team Valor horse capture the Queen Elizabeth II Cup, a race with international prestige. But the biggest thrill was about to come.

Seventeen of Animal Kingdom’s 20 shareholders — individuals who owned anywhere from 2.5 to 15 percent of the horse — came to Louisville to see their long shot run. They attended a Thursday night party for the owners, experienced the pre-race excitement of the Churchill Downs paddock and then the exaltation of going to the winner’s circle.

“It was like an out-of- body experience,” Furey said.

“It was surreal,” said Weil, who had been watching Kentucky Derbies since 1938 and never dreamed of getting this close to one.

Surely none of the 20 partners thought he was being shortchanged because he owned only a fraction of the Derby winner.

“The thrill is still the thrill,” Furey said, “as if it’s your own horse.”