After Smarty Jones was syndicated for future stud duty in a $39 million deal last month, cynics in the thoroughbred industry wondered if he would ever be seen in competition again. They anticipated the familiar ritual that precedes the disappearance of the sport's stars: the announcement of an injury that forces a horse's retirement to stud.

That scenario played out yesterday when the winner of the Kentucky Derby and Preakness was retired after a racing career that lasted less than nine months and gave only a hint of how good he might have been. Smarty Jones's career-ending injury was little more than normal wear and tear. Veterinarian Larry Bramlage explained that a bone scan had revealed bruising in the area of the fetlock -- the horse's ankle -- in all four legs, but said: "The risks are minor. We bring horses back from this injury all the time."

Smarty Jones could have resumed training after a two- or three-month rest, campaigned as a 4-year-old and tried to accomplish the things that he didn't have time to do at 3. He was retired less because of the risks to him than to the investors who paid $650,000 for shares in him as a stallion. Breeders rule the game -- often to the detriment of the sport.

"Economics always plays into any decision," acknowledged Robert Clay, owner of Three Chimneys Farm in Kentucky, where Smarty Jones will spend his stud career. And the economics of modern-day breeding and racing usually dictate that good horses go to the breeding shed as soon as possible.

Anyone who owns a good male racehorse can do the necessary arithmetic. Smarty Jones will be bred to 110 mares next year -- a relatively modest workload by contemporary standards. If his stud fee were set at a modest $75,000 (it will probably be higher), he would generate $8.25 million in earnings in a year's work as a stallion. No thoroughbred has ever earned that much in a season of racing, although Smarty Jones came close this year, with $7.5 million in winnings.

While breeding a horse is almost a can't-miss proposition (assuming he is fertile), racing him is full of risks. The animal can get hurt. His form can deteriorate. If this happened, he not only would fail to earn millions of dollars in stud fees, but his value as a stallion could decline because of his poor performances. As a result, the best 3-year-olds rarely race at 4 any more. Point Given, the star of the 2001 Triple Crown series, was retired in the summer of his 3-year-old year. War Emblem, winner of the Derby and Preakness in 2002, was sold for stud duty at the end of that season.

Although retiring horses early makes sense economically, anyone who loves the game has to deplore the practice. Most thoroughbreds don't reach their physical peak until they turn 4. Seattle Slew, Affirmed and Spectacular Bid were all acclaimed 3-year-old champions, but when they campaigned as 4-year-olds they reached a new level and produced some of the more brilliant performances in the history of the sport. Great efforts by great 4-year-olds are relatively rare in the sport nowadays.

John Servis, Smarty Jones's trainer, lamented yesterday that Smarty Jones wouldn't get this chance. For most of this year, Servis said: "His race in the Preakness showed a little hint of what he was capable of. He still was so immature. . . . He might have been the best of all time."

But Smarty Jones didn't accomplish enough to merit inclusion in a list of the sport's all-time greats. He ran one blockbuster race -- his 111/2-length romp in the Preakness.

However, he was dominating a 3-year-old crop that was of average quality at best. He never faced older horses. He never faced a truly formidable rival. The challenges that would have certified his greatness still awaited him.

His retirement underscores one of the reasons that the popularity of horse racing has declined so precipitously: The sport suffers from a shortage of recognizable stars. In the eras of Seabiscuit, of Citation, of Seattle Slew and Spectacular Bid, horses raced long enough to become celebrities and box-office attractions. Smarty Jones was becoming a star of their magnitude. His humble origins and his brilliant performances had captured the interest of America; his bid for the Triple Crown had lured a record crowd of 120,139 to Belmont Park. If he had raced for another year, he would have stirred more interest in racing than any 4-year-old in the last quarter-century.

Perhaps it is naive to criticize breeders for acting in their own self-interest and cashing in on stallion prospects as quickly as possible. But shouldn't they feel some responsibility to promote the well-being of the sport?

After winning the Kentucky Derby and Preakness, Smarty Jones will be bred to 110 mares next year.