A few posts back I posed a question to readers and solicited replies. I received many replies (thank you all very much), but none really answered my question.
The answer I was looking for is that “influence” (actual observed results) declines by MORE THAN 50% per generation, at least through the second generation.
We know this because “influence” declines by at least 50% per generation due to twice as many ancestors in each succeeding generation. And the first generation is more important than the second generation, which is more important than the third generation, etc. Put two and two together, and voila!!!!, the answer is four.
I qualified that statement with “at least through the second generation” because by the time you reach the third generation, results are already pretty close to 1.0 (the norm for the breed). There is not much room (if any) to decline at that point. So results can become pretty random (fluctuating around 1.0) at that point.
This might not be an ironclad rule. It might have more to do with the practices of breeders than anything else. If breeders showed more selectivity about the sires and dams they actually choose to use, “influence” could very well decline more slowly. As one reader has pointed out, quality of mares has something to do with it as well.
For example, take the seven or eight best sire sons of Northern Dancer. For the sake of argument, let us examine (in no particular order) Danzig, Nijinsky II, Sadler’s Wells, Nureyev, Storm Bird, Vice Regent, Dixieland Band, and Lyphard. Their composite (combined) record as sires is 1,171 stakes winners from 8,593 foals. That is 13.63%, slightly better than the 13% we would expect to see if “influence” decreased by ONLY 50% per generation.
So those eight sires held up pretty well, and if breeders had used only those eight sons of ND and NO OTHERS, ND’s “influence” as a sire of sires in the second generation would have held up much better. But of course breeders used just about any son of ND with testicles (just as they do today with the jillion sons of Storm Cat), and the result is that ND’s “influence” diminishes quickly. That is human nature, and it can not be changed.
So the next time you hear someone say, “Influence diminishes by 50% per generation,” in that dogmatic tone, here is my suggestion. Chuckle and say to yourself something like, “That might be true in a strictly theoretical sense, but in reality it works out somewhat differently.”
A few posts back I observed: “The intellectual foundation of science is observation, logic, and skepticism.” I do not wish to claim credit for originating this quote. I found it somewhere on the internet and appropriated it for my own purposes.
Theories are just hypotheses until they are proved or unproved by observation (actual results). You can familiarize yourself with all the breeding theories in the universe and call yourself a “pedigree expert” on that account. But unproven theories are nothing but “useless and pointless knowledge.”
Only two things about breeding Thoroughbreds have been proved over and over and over again by observation (actual results). “Uncle” Joe Estes was mainly responsible for bringing both to public recognition and acceptance. The two most efficient ways of determining the best breeding stock are the racing test and the progeny test.
Of the former Estes said: “There are no rules to breeding race horses. There are only odds and percentages. I am still waiting for someone to reveal a better way of calculating odds and percentages than by the use of racing class. But I do not expect to see any such calculation.” (Racehorse Breeding Theories, page 55).
Of the latter Estes wrote: “I have stated repeatedly that there is one test–and only one–more efficient than racing class for the selection of breeding material, and that is the progeny test. After the produce of a stallion or a mare have raced, you have before you the best evidence it is possible to obtain.” (ibid, page 57).
A corollary was expressed by Dewey G. Steele, “regarded as one of Kentucky’s most eminent authorities in the field of horse genetics.”
“Evidence from these [statistical] studies indicates that pedigrees should be judged primarily upon the basis of the first and second generations and that ancestors beyond the third generation may for all practical purposes be ignored.” (ibid, page 315).
“The famous racing writer Joe Estes came to a similar conclusion,” added RBT, “due to his research published in The Blood Horse.” (ibid, page 315).
I mentioned in one of my earlier posts that I think of myself as trying to extend the work of “Uncle” Joe Estes. I started thinking along those lines about 25 years ago. I started thinking about writing this particular series about 20 years ago. My original title for this series 20 years ago was “The Great God Dogma.”
Fortunately I decided 20 years ago to postpone this project. I did actually write some stuff, but no one was interested in publishing it. Which was probably just as well. I felt pretty confrontational about it all back then.
Nowadays I feel a lot less confrontational about it all. I think I see better now than I did back then how things get misinterpreted and mistranslated into dogma. Like I said earlier, it is just human nature, and human nature can not be changed. “All lies and jests!!!!/Still a man hears what he wants to hear and disregards the rest.” People will believe anything if it supports their own pet theories.
It reminds me of Galileo and the inquisition. Galileo pointed out that the earth could not possibly be flat. The inquisition disagreed. Galileo was punished by the inquisition. He lived under house arrest for the remainder of his life. But Galileo had facts on his side and eventually was acknowledged to be correct. The inquisition did not have facts on its side. The inquisition had only dogma. Facts trump dogma and theories any day of the week.
So I apologize in advance to anyone who feels like I am trying to convert them from one form of religion to another. That is the last thing on my mind. Religion does not care for facts at all. There is a place for religion in our lives.
But breeding Thoroughbreds is NOT the place for religion. All I am trying to say is that in endeavoring to breed better racehorses you should look at theories as religions and treat them accordingly. If you want to swallow them hook, line, and sinker, you are free to do so. You are also free to treat them with skepticism.
And on that note I will conclude with some wisdom from “Last Thoughts on Woody Guthrie”:
“You can either go to the church of your choice
Or you can go to Brooklyn State Hospital
You find God in the church of your choice
You find Woody Guthrie in Brooklyn State Hospital
Though it’s only my opinion
I may be right or wrong
But you find ’em both in Grand Canyon