AP -- Essential Quality is expected to be the first gray horse favored to win the Kentucky Derby in 25 years. A gray horse hasn't won the Derby since Giacomo in 2005, and only eight grays have won it since 1930.

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According to historians and experts, there are just fewer gray horses in the thoroughbred population compared to more traditional chestnut, bay,  brown and black horses. But with almost light gray Tapit siring Essential Quality and others, horses of that color could be making a comeback at the elite level of racing.

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