Which Kentucky Derby Winner Is the Biggest Stud?

After a horse wins the Kentucky Derby, you can bet that it becomes as valuable for its breeding ability as it was for its running ability in the race. However, despite 135 years of championship breeding, only one Derby winner has fathered more than one future winner, and just two bloodlines dominate the sport today.

Bold Venture, the winner of the 1936 Kentucky Derby, holds the record for siring the most future winners. As a post-Derby stud, he fathered two sons, Assault and Middleground, who won the Derby in 1946 and 1950, respectively, said Jordan Sterickler, who works for Bloodstock Research Information Services, a horse breeding information company. But after that, victories by Bold Venture's offspring came to an end.

The bloodlines of two other horses topped Bold Venture's progeny, once their second and third generation descendants are included.

The blood of Native Dancer and Seattle Slew courses through the veins of nearly every prominent race horse running today, Sterickler told Life's Little Mysteries. Seattle Slew is the only undefeated Triple Crown winner in history, and Native Dancer won both the Preakness and Belmont Stakes in 1953.

"Between Native Dancer and Settle Slew, you pretty much cover your bases on every horse that runs," Sterickler said. There isn’t a single horse running in the 2010 Kentucky Derby that isn’t related to one of those horses, and a number are related to both, he said.

Native Dancer was a successful racer, winning Horse of the Year in 1954, but would go on to even greater renown as a stud. One of Native Dancer’s grandchildren, Northern Dancer, won the 1964 Kentucky Derby and went on to earn the highest stud fee in racing history, said Headley Bell, president of Nicoma Blood Stock and who has bred other Derby champions. And Native Dancer’s great-great grandson, Mine That Bird, won the 2009 Derby.

Another of Native Dancer’s grandchildren, Mr. Prospector, sits atop of one of the most successful bloodlines of all time, having 10 Derby champions and eventual winners of every Triple Crown Race among his sons and grandsons, Bell said.

“If I had to pick the line with the most winners, I guess it would probably be the Mr. Prospector line,” Bell said. The other important bloodline today began with 1977 Triple Crown winner Seattle Slew. Of Seattle Slew’s progeny, his son Swale won the Derby and the Belmont Stakes, and his grandson Cigar won more money racing than any horse in history.

Although breeders now keep records of horse racing families so detailed they rival those of Japan’s royal dynasty, looking back, the horse bloodlines start becoming unclear beyond four or five generations ago, Sterickler said. And interbreeding makes it impossible to trace back distinct bloodlines past the 1950s.

Oddly enough, if one goes back even farther, the lines become clear again, Sterickler said, because all thoroughbred race horses alive today descend from three stallions that lived in the early 1700s: Byerley Turk, Darley Arabian, and Godolphin Arabian.

Stuart Fox currently researches and develops physical and digital exhibit experiences at the Science Liberty Center. His news writing includes the likes of several Purch sites, including Live Science and Live Science's Life's Little Mysteries.