Animal Kingdom won the Kentucky Derby by 2 3/4 lengths. Shackleford held his rival by a half-length to take the Preakness two weeks later.
Now Saturday's Belmont Stakes is being billed as the match-up between these two colts, with the winner gaining both a measure of revenge and a slight edge for year-end championship honors.
However, the real match won't take place until the two have wrapped up their racing careers - the breeding shed is the final showdown.
As much as Animal Kingdom, Shackleford and the rest of their Belmont rivals will accumulate in purse money on the race track, that number pales in comparison to what their worth could be upon entering stud duty.
"The stud fees, the stallions, are like the stock market. When business is good and production is good, values go up," said Jim Tipton, stallion manager of Wintergreen Stallion Station near Midway, Kentucky.
In 1973, Triple Crown champion Secretariat was syndicated for $6 million, a record at that time. Just four years ago, a reported $50 million deal was reached for Big Brown to stand at Three Chimneys Farm near Lexington, Kentucky.
That particular arrangement came together even before the colt competed in, and won, the Preakness. Three weeks later, Big Brown's Triple Crown bid ended when he pulled up without finishing the Belmont. He entered stud duty for a $65,000 fee.
"Each stallion is an individual and some you can't leave out as much as others, but they would generally be turned out at night and then (put) up (in their stall) in the day during the summer months," Pope McLean Jr., business manager for Crestwood Farm near Lexington, Kentucky, described the operation's policy toward its stallions. "In the winter months, they're kept up at night."
Crestwood, like many farms, breeds their stallions around three times a day - morning, afternoon and early evening. The stallions are washed, groomed and readied for their scheduled appointments, then usually turned out to relax until time for the whole process to be repeated.
According to Travis White, the stallion nominations manager for Taylor Made near Nicholasville, Kentucky, a stallion can cover 140 mares each breeding season, which runs through June.
"It depends on how popular a stallion is," he explained. "Generally we try to be around 120, but if we have a lot of demand sometimes we'll go up to 135 or 140 if the horse is doing well."
Current in-demand stallions can reach as many as 200 mares bred per season, but the average number of foals born varies dramatically. The Jockey Club maintains breeding statistics on each stallion, with reports on how many mares are bred, the number of actual pregnancies and how many foals are born.
For instance, 2004 Kentucky Derby and Preakness winner Smarty Jones covered 56 mares during 2009, with 42 reported in foal. Of those, 36 produced live offspring, resulting in a 64-percent live foal rate.
"The biggest thing, I think, is that you pay attention to what kind of mares you're breeding. That you really match up the horse with the proper mares and the proper pedigrees," Tipton explained. "In the first couple of years it's really going to be important. We want to be sure we give him the best opportunity to get a good crop out there and get horses that will perform in those first two years. Because after that, if they don't perform in the first two years, a lot of breeders will jump off of them."
A nice book of mares will be available for Animal Kingdom and Shackleford their first year at stud, but recent history is not on the side of this year's classic winners maintaining their popularity.
"The majority of your stallions, in four to five years, will not be standing for the same fee that they did the first year they came in," Tipton remarked. "We've seen numerous times where we have these really nice Grade 1 winners and people spend a tremendous amount of money on them and then in four or five years you don't see them as stallions anymore."
"You have to look at everything," McLean explained. "The sire line, the strength of the female family, quality of race career, conformation, was the horse precocious. If a horse ticks off all the right boxes, then you're going to be able to set a much higher stud fee."
While Animal Kingdom and Shackleford could enter stud at a higher fee than their contemporaries, those numbers likely won't reach what recent classic winners have demanded their first year in the breeding shed.
"It's changed a lot in the last few years," White said. "It's changed significantly from back in the days when some of these horses would come off and stand for $100,000 plus."
Smarty Jones, who entered stud as the first undefeated Kentucky Derby winner since Seattle Slew, provides a good example. Though he didn't win the Belmont, the chestnut was assigned a $100,000 fee for his first season in 2005.
Through last year he has sired nine stakes winners from three crops to race. In 2010 his stud fee was reduced to $10,000. This year he's been relocated from Three Chimneys to Ghost Ridge Farms near York, Pennsylvania.
The current economic downturn hasn't helped matters, bringing sharp reductions in stud prices for not only classic winners but the entire breeding industry.
"It's gotten very competitive standing the stallions. There's fewer mares being bred, and each stud farm is doing their best to be as competitive as possible," McLean admitted. "It creates an extremely competitive environment."
The racing accomplishments of Animal Kingdom and Shackleford have already ensured that they'll get their chance in the breeding shed. But the success of their offspring will determine whether or not the classic winners will achieve victory off the track.
"You have to be committed," McLean asserted. "There's so many variables that you don't have control over. If you breed a mare and have a foal, it's going to take a while before that foal hits the track and you actually see results.
"But, I think it's probably one of the best times, if you take a contrarian view of it, to think about buying a mare because your money will go further.
"But I'm a breeder so of course I'm going to think that way."