The Kentucky Derby field is the most heavily scrutinized of the year in North America, yet much remains unknown about the group until after the race is over.
Most important among the race's variables is which horses are best able to handle the Derby's 1 1/4-mile distance, a route of ground that no horse in the field will have raced before and most never will again. Because there is no prior form with which to evaluate horses at the classic distance, a useful tool to determine each entrant's potential is the average progeny winning distance of his sire and dam.
Although far from an exact science, AWD numbers can provide a snapshot of a sire or dam's ability to impart stamina into his or her offspring, independent of the reputations that names on a pedigree page can bring with them. The higher a sire or dam's AWD, the more likely it is that his or her foals can handle a route of ground, because they've done it in the past.
The AWD figures can help identify a longer-priced horse capable of filling out exotics based on his natural stamina.
Horses who finished at or near the top of their race's AWD rankings at double-digit odds include 2013 Derby runner-up Golden Soul at 35-1, 2013 Preakness Stakes winner Oxbow at 15-1, 2014 Belmont Stakes runner-up Commissioner at 28-1 and Belmont third-place finishers Keen Ice (2015, 17-1) and Lani (2016, 12-1).
Taking into account the comparative AWDs from the sires and dams of this year's Derby field, Grade 2 Tampa Bay Derby winner Tapwrit appears best equipped to handle the distance.
Owned by Eclipse Thoroughbred Partners, Bridlewood Farm and Robert LaPenta, Tapwrit is the only horse in this year's Derby field whose sire and dam both ranked in the top five of their respective categories, and that gives him the best combined score.
Tapwrit is a son of perennial leading sire Tapit, whose AWD of 7.53 furlongs ranks third among this year's Derby sires. Tapit, a resident of Gainesway in Lexington, Kentucky, has well-established distance credentials as the sire of two Belmont Stakes winners: Tonalist in 2014 and Creator in 2016.
Tapwrit's dam, Grade 1 winner Appealing Zophie, finished tied for fifth among this year's Derby broodmares with an AWD of 7.93 furlongs from three winners. Contributing heavily to that figure was the Bernardini gelding Daddy in the Dark, who tallied three wins at a mile to 1 1/8 miles.
Tapwrit has won twice at a mile and scored in the Tampa Bay Derby at 1 1/16 miles.
Tapwrit was a $1.2 million purchase out of the 2015 Fasig-Tipton Saratoga select yearling sale, and a strong Derby performance would go a long way toward helping his connections recoup or even turn a profit on that investment.
"With his scope and his pedigree and the efficiency of his stride, we certainly have more and more believed that the classic distance was going to suit him especially well," said Aron Wellman, president of Eclipse Thoroughbred Partners. "Then, when you factor in his style, where he's reserved then produced for the last three-eighths of a mile -- that turn of foot he displayed in the Tampa Bay Derby -- we think his style is just another enhancer to help suggest the classic distance will suit him very well."
Five horses tied for the second-best combined score in the AWD rankings: Battle of Midway, Irish War Cry, Lookin At Lee, McCraken and Gormley.
The late Smart Strike, the sire of Battle of Midway, led this year's Derby stallion class with an AWD of 7.72 furlongs.
A former resident of Lane's End, Smart Strike has had 18 crops of racing age, more than any sire represented in this year's Derby. His greatest success at stud was two-time Horse of the Year Curlin, who finished in the top three in all three Triple Crown races, including a win in the Preakness Stakes, and went on to rack up 10-furlong wins in the Breeders' Cup Classic, Dubai World Cup and two editions of the Jockey Club Gold Cup.
Smart Strike's son English Channel was a multiple Grade 1 winner beyond the classic distance.
Curlin (the sire of Irish War Cry) tied for second by AWD with Tiznow (the sire of Irap) at 7.63 furlongs.
Five first-crop sires are represented in this year's Derby field, which means their AWD figures could change dramatically as their foals mature and more route races are made available to them. To Honor and Serve, the sire of State of Honor, topped the rookie Derby sires with an AWD of 7.11 furlongs, placing him ninth overall.
Windyindy, the dam of Patch, topped the broodmare class. Her three winners from as many runners have an average winning distance of 8.43 furlongs.
Her first foal, Tiz Windy, by Tiznow, won four times at 1 1/16 miles, including the Grade 2 Indiana Oaks. Windyindy's foal Makin' Sense, by Street Sense, was an allowance winner at 1 1/8 miles, while Patch, by Union Rags, won his maiden at a mile.