The Possible and the Probable
by Roger Lyons
In previous posts I’ve noted that breeding methods are subject to conditions of possible effectiveness. That is to say, any given topic of pedigree discussion–a nick, a method of inbreeding, any combination of one ancestor with another–can yield a stakes winner if certain conditions are met by the specific cross. By definition, a cross that does not meet any conditions of possible effectiveness has virtually no chance of yielding superior performance. We can’t always know whether or not a cross meets conditions of possible effectiveness, but, given what is at stake, any evidence of such conditions is worth considering.
I would go so far as to submit that the conditions of possible effectiveness are crucial to determining the probability of superior performance from a cross. Here’s a case in point.
Last year I mentioned the nick between Galileo and the sons of Doubly Sure–Kris (by Sharpen Up), Diesis (by Sharpen Up), and Presidium (by General Assembly). At that time, 25 mares with one of those three sires in their ancestries had produced foals by Galileo, and six different crosses had yielded superior runners, including three G1 winners (Sixties Icon, Lush Lashes, and Cape Blanco) and New Zealand, which ran second in the Irish St. Leger (G1). Since then, Gallic Star, whose third dam is by Kris, won the listed Silver Tankard S. in England, bringing the total number of superior runners to seven.
Thus, assuming a mare of similar quality in some descent of Kris, Diesis, or Presidium–all out of the mare Doubly Sure–the probability that she can produce a Galileo foal capable of superior performance is at least .28, the probability of a G1 winner at least .12. Don’t get caught up in the fact that Kris and Diesis are by Sharpen Up. Galileo’s record of 7/53 with Sharpen Up suggests only a .13 probability of superior performance (not adjusted for the conditions of possible effectiveness).
But, we know from the numbers that the presence of a son of Doubly Sure in the ancestry of a mare is a condition of possible effectiveness for offspring of Galileo. That condition is met by 24 of the 53 mares with Sharpen Up in their ancestries, and six of those seven dams of superior runners met that condition. This means that Galileo’s strike rate with mares in descent of Sharpen Up, but not through a son of Doubly Sure, was only 1/29, with a probability of only .034 of yielding a superior runner. In other words, those cases do not meet Galileo’s conditions of possible effectiveness with Sharpen Up.
It’s perfectly reasonable to think of the probability of success as a frequency of superior performance from opportunity, but that reasoning goes wrong in thinking of opportunity as nothing more than the number of times a cross has been tried. It might be fair to say that the number of times a cross has been tried constitutes its nominal opportunity, but the real opportunity is defined by the cases that actually meet conditions of possible effectiveness. An “opportunity” that has virtually no chance of success is an opportunity you can do without, especially when trying to pin down a true probability of superior performance.
Possibly the possible effectiveness of Diesis and Kris is rooted in the fact that these two full-brothers were exceptionally well-proven sires of classic fillies from mares by a variety of broodmare sires.
Diesis sired three winners of the English Oaks: Diminuendo, Love Divine, and Ramruma plus Pricket which ran 2nd and Sacred Song, 2nd in the Yorkshire Oaks.
Kris sired two winners of the English Oaks: Unite and Oh So Sharp plus Shamshir and Sudden Love which ran 2nd, Rafina which won the French Oaks (Prix Diane) and Hawajiss, 2nd in the Irish Oaks.
April 17th, 2011 at 8:29 pmQuite right, Allison. Quality of breeding stock is always a necessary condition of possible effectiveness, and sometimes it may even be a sufficient condition.
April 18th, 2011 at 8:09 am