Nyquist’s impressive victory in Saturday’s Grade 1 Florida Derby all but assures that the unbeaten champion 2-year-old male of 2015 will start as the favorite for the Kentucky Derby. Nyquist’s Florida Derby victory, however, will not remove the doubts many pedigree pundits have raised about whether or not there is sufficient stamina in his pedigree for him to stay the 10-furlong Kentucky Derby trip. In the age of genetic sequencing, both our understanding and our writing about stamina in pedigrees tends to be overly simplistic. But absent inside knowledge about what alleles lie in a critical position on Nyquist’s Myostatin gene, the size and efficiency of his heart, and the efficiency of his biomechanics, pedigree – which is basically a history of his ancestors – is the best guide we have. Nyquist’s sire – Uncle Mo, a particularly brilliant champion 2-year-old male – did not win beyond 1 1/16 miles, but really had very little opportunity to do so since a debilitating illness knocked him off the Triple Crown trail before the Derby. He came back that fall to win the Grade 2 Kelso at a mile in brilliant style, but, not surprisingly after such an interrupted campaign, he faded to 10th, though beaten only 6 3/4 lengths, by Drosselmeyer in a singularly lackluster Breeders’ Cup Classic. It is impossible to know how far Uncle Mo would have stayed given the opportunity for more conventional preparation. And since Nyquist is from his first crop, we have no evidence of his distance profile as a sire. :: DRF BREEDING LIVE: Real-time coverage of breeding and sales Nyquist’s pedigree has been criticized because his dam and most of his closest relatives along his female line have been sprinters, with little evidence supporting the idea that they might have been able to pass along the genetic characteristics necessary to carry a Thoroughbred 10 furlongs. Nyquist’s dam, Seeking Gabrielle, by Forestry, won once at six furlongs in very modest company at Louisiana Downs, and it is fair enough to say that all of the black-type animals descending from her stakes-winning dam, Seeking Regina, by Seeking the Gold, earned that black type at distances of 1 1/16 miles or less. But how important is this really? Well, if one looks at the same information on the dams of the last five Kentucky Derby winners, the answer has to be perhaps not very much. Littleprincessemma, dam of 2015 Triple Crown winner American Pharoah, raced twice without placing at 5 1/2 and six furlongs, and exactly the same criticism could be (and was) levelled at the black-type horses under her stakes-winning dam.  Love the Chase, dam of 2014 Derby and Preakness winner California Chrome, scored her only victory at a mile in very modest company, and though there is no black type under her dam, the black-type horses under California Chrome’s stakes-winning third dam, Chase the Dream, by Sir Ivor, likewise showed little to no proclivity for distances beyond 1 1/16 miles. Essentially the same story is true of Arch’s Gal Edith, dam of 2012 Derby/Preakness winner I’ll Have Another, but the dams of 2013 Derby winner Orb and 2011 Derby winner Animal Kingdom where both winners over 10 furlongs or beyond from classy families packed with distance runners. The problem underlying all of this pedigree analysis is a gigantic flaw in the structure of American racing. A majority of American races are run at slight variations of two distances – six furlongs and a mile. So few races of any description are now available at 10 furlongs and beyond that it has become a fool’s game to predict how far a given horse will run based on the distances his close ancestors apparently preferred given their own race records. How does one know if a horse can stay 10 furlongs if they are never given the opportunity? Besides, with the strong influence on preferred distance that one mutation on the Myostatin gene has been proven to exert, it is easy to illustrate that Nyquist could have a double dose of stamina at that position. Since Uncle Mo won at 1 1/16 miles, it is certainly possible, even likely, that he is heterozygous at that position, meaning he will donate a stamina gene to 50 percent of his offspring and a sprinting gene to the other 50 percent. Likewise, Forestry, a Grade 2 winner at 1 1/16 miles, could readily have passed on a stamina gene to Seeking Gabrielle, despite the distance of her lone win, or indeed it could have come from 1 1/4-mile winner Seeking the Gold, sire of Seeking Gabrielle’s dam, Seeking Regina, or from anywhere else in her pedigree. If Nyquist is heterozygous at that position on the Myostatin gene, his chances of staying the Kentucky Derby trip are pretty good, given compatible heart and biomechanics. If he is double stamina, the chances are excellent. On the flip side, there are plenty of American horses who are double sprint at that position who can win at nine furlongs. Very, very few of those, however, can stay that next furlong. We will not find out exactly what is inside Nyquist until around the eighth pole at Churchill Downs.