Wednesday, July 8, 2009

Vuillier and the Triple Crown

Before they proved they were top-class runners, the pedigrees of the three winners of America's 2009 Triple Crown races would not have been described as fashionable. Indeed, Mine That Bird famously sold for only $9,500 as a yearling, while neither Rachel Alexandra or Summer Bird were offered at public auction.
Fashion be damned. As shown by the data below (please forgive my ignorance of how to make the columns come out neatly in HTML code), their pedigrees are actually well within the norm of contemporary top-class pedigrees.

Archetype Mine That Bird Rachel Alexandra Summer Bird
Blue Larkspur(100) 56 88 104
Bold Ruler(157) 128 128 128
Buckpasser(108) 32 0 160
Hail to Reason(94) 0 256 0
*Mahmoud(118) 104 168 152
Man o' War(116) 108 132 168
Mr. Prospector(256)640 256 128
*Nasrullah(243) 240 144 208
Native Dancer(199)352 224 256
Nearco(279) 280 280 288
Northern Dancer(296) 512 512 640
Phalaris(178) 170 218 164
Plucky Liege(118) 111 148 125
*Princequillo(151) 144 160 192
*Ribot(75) 0 192 0
Seattle Slew(120) 0 0 0
War Admiral(85) 60 56 136

The data presented above are based on research by the author on a new implementation of the Vuillier dosage system published in the December 13, 2008 issue of Thoroughbred Times. The dosage numbers in parentheses represent the average genetic contribution of the archetypes listed to the pedigrees of the winners of the most important races in America since the institution of the Breeders' Cup in 1984. (You can read the article by clicking on the link titled “A new understanding of Vuillier dosage” on the right hand side of the page.) The numbers in the three unfortunately jagged columns are the dosages of the same archetypes in the pedigrees of Mine That Bird, Rachel Alexandra and Summer Bird.
The archetypes chosen for display here are actually the ones that produce the most varied dosages among these three pedigrees—their pedigrees are virtually identical on the other most significant influences on contemporary pedigrees. Indeed they are close to identical on a few of the archetypes included here as examples, like Bold Ruler, Nearco and Seattle Slew.
Naturally the widest variations in dosage are on the youngest archetypes listed, like Buckpasser, Hail to Reason, Mr. Prospector, Northern Dancer, *Ribot and Seattle Slew. That is the way pedigrees work. The genetic influence of the most significant sires and dams gradually stabilizes as time passes and their names recede further into the background of pedigrees.
The Vuillier system, though, gives a holistic view of pedigrees and offers tremendous insight into the direction one should take with matings.
For example, the pedigrees of Rachel Alexandra and Summer Bird are complementary in many ways. Rachel is above the norm in Hail to Reason, *Mahmoud, Phalaris, Plucky Liege and *Ribot, while Summer Bird is either below the norm or at least lower than Rachel in all five of those influences. Conversely, Summer Bird is high in Blue Larkspur, Buckpasser, Man o' War and *Princequillo, while Rachel's pedigree is less saturated with those powerful influences.
In a conventional pedigree presentation, it is easy to see that both Rachel Alexandra and Summer Bird have plenty of Northern Dancer and Mr. Prospector in their pedigrees, but it is simply impossible to see the imbalances in more distant but still vitally important ancestors. The Vuillier system makes those imbalances obvious.
The Vuillier system is based on the assumption that a mating that produces a pedigree more similar to the pedigree of the winners of the best races is more likely to produce another winner of those same races than one that does not. Indeed that is the same assumption behind other popular mating systems like nicking and even biomechanics (in an indirect way).
That is the beauty of the Vuillier system, and the implementation I devised with the help of Simon Morris at TesioPower and described in the linked article. It provides the ultimate in flexibility in applying those insights.

1 comment:

  1. Ann Clemmens FerlandAugust 16, 2009 at 4:22 PM

    A system like the Vulliers or Varola methods was always going to be more relavent than the Roman method with its emphasis on only the first few generations and use of active stallions whose full importance and/or style of influence is not yet known. The horses on your list certainly do conform to the 'breed-changing' description of 'chefs-de-race', however I fear it would be of use only for North American-blooded horses. Of course, you probably didn't intend it for any other population, just as Vulliers' analysis was intended only for the contemporary British/Irish breeding population.