The Sire of Sires Effect TABLE 1 Top 10 Stallions by Number of Sire Sons, 1956-2010 Sire Sire Sons Mr. Prospector 233 Northern Dancer 191 Danzig 185 Nijinsky II 157 Seattle Slew 138 Storm Cat 133 Danehill 123 Bold Ruler 92 Sadler's Wells 81 Damascus 69 self-fulfilling prophecy—the more success- TONY LEONARD ful the sire, the more his sons will be tried Mr. Prospector was the most prolific sire of sons at stud over the past several decades at stud, with the ill-placed belief that even the most mediocre son of this elite sire may prove successful (which they invariably the common ancestor source based is concerned, there is no difference don’t). Both Northern Dancer and Mr. Pros- on the genetic data in the study. between Northern Dancer and Mr. pector are widely considered sires of sires, This Y chromosome haplotype now Prospector. and it is noteworthy that they head the list dominates 95% of the entire breed. The term “sire of sires” is equally of stallions with sons that have sired at least The authors did not find any more ill defined. If we define that term one stakes winner in their careers. recent Y chromosome mutations based solely on the concept of the If we define a sire of sires as a stallion that would point to newer selection raw number of sons that retire to that left a significant number of sons whose pressure or a change in the over- stud by a given sire, it is nothing career at stud could at least be termed suc- all genotype of modern stallions. more than a popularity contest cessful, then we are starting to get closer to Thus, as far as the Y chromosome and one that to a certain extent is a measuring the sire-of-sires concept. To de- ANNE M. EBERHARDT there is a generally accepted notion of his- The Sire-of-Sires Effect: torical classification following the paternal lines of Thoroughbred pedigrees. Racehors- es are considered to be “from the Northern Myth or Reality? Dancer sire line” or “from the Mr. Prospec- tor sire line,” though determining when a Are sons of certain sires more likely stallion heads his own branch becomes a lit- tle problematic. When, for example, did Fap- to succeed as sires themselves? piano become a line apart from his own sire, Mr. Prospector? Who makes such desig- BY BYRON ROGERS nations? From a genetic viewpoint, there is no horoughbred breeding strategies and terminology tend to be rooted such muddying of the waters. More than Tin historical traditions, often simply predicated by the belief if some- 95% of sire lines in the Thoroughbred share Whether on the racetrack or in the sales thing is said enough, it is an irrefutable fact. One such phrase still often the same Y chromosome sequence. One ring, success is not an accident. used anoints a stallion as a “sire of sires,” a title usually reserved for those scientific study on the classification of the breed based on the sequencing of the Y stallions that leave a handful of successful sons, with the assumption that For over 25 years, we’ve helped guide chromosome did point to a mutation in the denalistud.com our clients’ successes they have passed on some type of genetic goodies other stallions can’t. Y chromosome that occurred somewhere 859-987-6212 | c: 859-621-7877 In examining the concept of a sire of sires, the difference between the between the father-son trio of Eclipse-Pot- terms “sire line” and “sire of sires” needs clarification. In regard to sire line, 8Os-Waxy, with Whalebone (b. 1807) being 40 / BloodHorse.com / SEPTEMBER 12, 2015 / TheBloodHorse / BloodHorse SEPTEMBER 12, 2015 / BloodHorse.com / 41 The Sire of Sires Effect TABLE 2 Watch looked at the stud TABLE 3 TABLE 4 TABLE 5 careers of 5,391 stallions Top 15 Stallions by Number that stood between 1956 Danzig’s Sire Sons by % SW/Fls Leading Sires by Sire Sons’ Top 12 Stallions by and 2010 and sired at least of Successful Sire Sons, one lifetime stakes winner. ■■Danzig – 17% SW/Fls Lifetime Stakes Winners/Foals Percentage of Successful These 5,391 stallions were ■■ Danehill – 14% Sons’ SW/Fls Sons’ SW/Fls Sons’ SW/Fls Sons’ SW/Fls 1956-2010 Stallion Sire Sons, 1956-2010 sired by 1,353 different . Multidimensional – 12% <2.2% >2.2% >5.0% >11.5% Successful Sons sires, giving us a broad look Successful Sons Sire Sire Sons . Danehill 36% 64% 7% 1% Sire Sire Sons (% Sire Sons) at sire-son performance. Redoute’s Choice – 9.1% (% Sire Sons) Danzig 46% 54% 6% 1% Northern Dancer 191 35 (18%) To define a successful . Dansili – 8.7% Hail to Reason 32 8 (25%) Mr. Prospector 46% 54% 15% 3% Mr. Prospector 233 34 (15%) sire, we took the lifetime . Mozart – 8.0% His Majesty 24 5 (21%) Sadler’s Wells 62% 38% 17% 2% Bold Ruler 92 31 (34%) number of stakes winners . Fastnet Rock – 7.3% Dixieland Band 27 5 (19%) to the number of foals of Storm Cat 54% 46% 8% 0% Nijinsky II 157 13 (8.3%) . Danehill Dancer – 6.6% Fleet Nasrullah 21 4 (19%) racing age (SW/Fls) and Average “Sire of Sires” 47% 53% 12% 2% Danzig 185 12 (6.5%) found that for all 5,391 stal- . Exceed and Excel – 6.3% Roberto 57 11 (19%) Roberto 57 11 (19%) lions, the average SW/Fls . Flying Spur – 5.4% Sir Gaylord 30 5 (17%) Damascus 69 10 (14%) was 2.2%. Stallions that . Rock of Gibraltar – 5.4% That said, just 6% of his sons could be and Storm Cat. Is their distribution of Valid Appeal 24 4 (17%) had a SW/Fls ratio of 5.0% considered successful while another successful sire sons any different than Native Dancer 43 10 (23%) ■■ War Front – 9.5% Hoist the Flag 45 7 (16%) or better were one standard 38% fell above the average of 2.2% the average of the 66 stallions consid- ■■ Ribot 65 10 (15%) Ribot 65 10 (15%) deviation above the aver- Striding Out – 8.3% SW/Fls. ered sires of sires? Sadler's Wells 81 10 (12%) age (thus in the top 32% ■■ Voyageur – 9.1% Table 4 shows Danehill as the most From the figures in Table 4, only Mr. Round Table 52 8 (15%) Danehill 123 9 (7.3%) of all stallions) and those ■■ Polish Numbers – 9.1% successful of Danzig’s sons at stud by Prospector and Sadler’s Wells have out- Noholme II 29 4 (14%) Hail to Reason 32 8 (25%) with 12% SW/Fls were in ■■ Green Desert – 7.6% lifetime stakes winners to foals and performed the average set by the criteri- Tudor Melody 37 5 (14%) the top 5% of all stallions in turn, with consideration to the un- on of 5% or more lifetime SWs/Fls. The Never Bend 55 8 (15%) . Oasis Dream – 8.9% at two standard deviations proven War Front, the most successful numbers for Sadler’s Wells are rather Round Table 52 8 (15%) above the average (remem- . Invincible Spirit – 6.8% of Danzig’s sons to sire successful sires interesting as at the start of his career, of stallions that stand at stud world- Seattle Slew 138 8 (5.8%) ber when the metric of 10% . Cape Cross – 5.0% themselves. Is it merely a case of suc- outside of In the Wings, Barathea, Fort wide but also the variety of sire lines, Storm Cat 133 8 (6.0%) SW/Fls indicated a “good” ■■ Chief’s Crown – 7.5% cessful sires that leave high-class sons Wood, and Scenic, Sadler’s Wells had with both numbers diminishing as sire?). We decided one stan- (a prerequisite of being successful in more success as a sire of National Hunt standing stallions has become more Turn-to 34 8 (24%) . Concerto – 5.2% dard deviation above the the first place) having a greater oppor- sires than flat racing sires. The trium- commercialized. average, or a figure of 5.0% ■■ Anabaa – 6.7% tunity just because more of their sons virate of Galileo, Montjeu, and High Looking at the same data but ar- fine this further and take it away from a SW/Fls was a sufficient ■■ Exchange Rate – 6.5% go to stud? Chaparral, along with U.S.-based El ranging it by the percentage of sons popularity contest, we first took the data level to define a success- ■■ Boundary – 5.2% The five most common sires of sires Prado, righted the ship. that were successful (Table 5) creates and established a metric that defines a ful sire; generally speaking in the modern era are Danehill, Dan- This phenomenon might speak to an interesting picture, quite possibly ■■ Pine Bluff – 5.2% “successful” sire. From The Jockey Club these were at least useful zig, Mr. Prospector, Sadler’s Wells, the narrowing of not only the number pointing to opportunities lost for the ■■ Information Systems database Market- sires with long careers. Hard Spun – 5.0% industry, or at least casualties of the commercialization of stallions. The In order to reduce the outliers and truly Turn-to trio of Sir Gaylord, Hail to measure the sire-of-sires effect, we further Reason, and Roberto featured in the pruned the data to those with at least 10 top 10 stallions by percentage of suc- sons at stud, at least two of which proved cessful sons at stud. Despite its suc- successful by the 5.0% SW/Fls criterion— cess this sire line is now on the wane a sire that has one successful sire son is, worldwide with just a handful of sons after all, a sire of a good stallion, not a sire of Dynaformer, Kris S., Arch, Al Mufti, of sires.