Kentucky Derby

There could be a gray in this year’s Derby winner’s circle. Why do they look like that?

Walk near the betting windows or along the paddock on a day of live Thoroughbred racing, and you’re bound to hear it if a horse of a certain color is preparing for a trip to the starting gate.

“I always bet the gray,” is the common refrain, especially among the casual bettors.

No race brings out more casual bettors than the Kentucky Derby, and this edition of the 3-year-old showcase will feature a trio of grays on which to wager. Those three colts — Roadster, Tacitus and Gray Magician — will also have a chance to end a 14-year skid for grays on the first Saturday in May and become just the ninth Derby champ of their pigmentation since World War II.

Not since Giacomo pulled one of the biggest Derby upsets in history at 50-1 odds back in 2005 has a gray made its way to the winner’s circle. A total of 25 horses classified as gray/roan have run in the Derby since. None of them won the race.

Roadster and Tacitus — from the barns of trainers Bob Baffert and Bill Mott, respectively — should be among the favorites in this year’s field. Roadster comes to Louisville off a victory in the Santa Anita Derby, and Tacitus has been victorious in the Wood Memorial and Tampa Bay Derby over his last two starts. Gray Magician — second in the UAE Derby in Dubai a few weeks ago — will be among the Kentucky Derby’s longest shots.

All three will likely find plenty of followers Saturday afternoon.

Roadster, with Mike Smith aboard, won the Grade 1, $1 million Santa Anita Derby horse race on April 6 at Santa Anita Park. AP

Our fascination with the grays has been around for as long as they have.

So, how did they come to look like this?

Dr. Kathryn Graves, the director of Genetic Testing at the University of Kentucky’s Gluck Center, explains that the gray coloring in horses is actually the result of a mutation of a particular gene (STX17).

“The effect of the mutation is that — all gray horses are born what we would call a ‘normal’ color.” Graves said. “There are other genes that determine color in the horse — whether a horse is bay or chestnut or black. So, all gray horses are born the color they would be if they did not also inherit the gray gene.

“But if the gray gene is present, then this mutation causes a gradual loss of melanin from the hair follicle. And so every time the horse sheds its coat, the hair follicles do not produce any new melanin. And so over time — with each change of coat — the melanin decreases.”

There’s some pretty precise math on the gray gene and its effect on a horse’s coloring.

In general, if a foal has one gray parent, it would have a 50 percent chance of being gray itself. If both parents are gray, that probability increases to 75 percent. Those numbers are in the case of one or both parents having just one copy of the gray gene, and the likelihood of a gray offspring would increase further if two copies of the gene were present — all the way up to 100 percent if both parents have two copies of the mutated gene.

“What that also means is that at least one parent must be gray,” Graves said. “You can’t get a gray horse from breeding two non-gray horses together.”

Tapit is one of the world’s top stallions and the father of Kentucky Derby contender Tacitus. Lexington Herald-Leader

The sire of Tacitus, of one of this year’s top Derby contenders, is Tapit, who was the leading stallion in North America from 2014 to 2016 and has produced three recent Belmont Stakes winners (Creator, Tapwrit and Tonalist) but is still in search of his first Kentucky Derby winner.

Tacitus appears a little darker than his famous father was during his racing days. Tapit, foaled in 2001, looked the part of the traditional gray when he won the Wood Memorial before finishing ninth behind Smarty Jones in the 2004 Kentucky Derby.

Tapit, now 18 years old and standing stud at Gainesway Farm in Lexington, has since morphed into an almost-white coloring. That lightening of the coat over time is another staple of the grays, and the manner and speed in which it occurs differs.

“Some gray horses have a very uniform loss of pigment,” Graves said. “Some horses gray very quickly. Some horses, like Connemara ponies, for example, some of them can stay a relatively dark gray into their teens. They never become white. Most gray horses eventually become white, or what’s called a flea-bitten gray, where some speckles of pigment remain.”

Tapit came up short in his Kentucky Derby try, but there have been eight winners of the race classified as gray/roan since dependable statistics on the subject began in 1930. That lot includes Silver Charm, Spectacular Bid and Winning Colors, the 1988 champ and last filly to win the Derby.

The Kentucky Derby was the only race Native Dancer — nicknamed “The Grey Ghost” — ever lost. He won 21 of 22 starts and was the runner-up in the 1953 Derby, becoming a national sensation in part because his light coat was easier to distinguish on the black-and-white televisions of the day.

Native Dancer was also a wildly successful stallion, and his genes have been passed down through many of the greatest racehorses of the past several decades. Roadster, Tacitus and Gray Magician all have Native Dancer in their bloodlines, and he’s actually responsible for the gray gene — going six generations back — in Roadster.

The beauty of the grays does come with a price, however.

Graves said it’s estimated that between 70 and 80 percent of gray horses will develop melanoma as they age. “So there’s kind of a downside to that attractive color,” she said.

According to statistics provided by The Jockey Club, a total of 8.7 percent of North American starters in 2018 were classified as gray/roan. The Jockey Club officially lumps in roan — a coat where with a mixture of red and white hairs or brown and white hairs — with gray to reduce the number of corrections that occur when trying to differentiate those colors.

As for our collective fascination with the rare coloring, there’s no scientific answer.

The grays are indeed easier to spot on the racetrack, and they stand out among their competitors in the paddock. Graves noted that military leaders of the past often rode atop gray horses that were easier for their own troops to locate on the battlefield. Napoleon Bonaparte, Simon Bolivar and Robert E. Lee all had famous war horses with the coloring.

The real reason why humans like gray horses is probably a simple one. They’re nice to look at.

“I think it’s just human nature that we like something different. That’s just my opinion,” Graves said. “Certainly, many people consider it a, not only different, but a very pretty color to look at. And that’s been true throughout history. … I think it’s just an attractive color mutation.”

145th Kentucky Derby

When: 6:50 p.m. Saturday

Where: Churchill Downs in Louisville


Purse: $3 million (Grade 1)

Distance: 1 1/4 miles (dirt)

Post-position draw: 11 a.m. Tuesday

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