The following was originally published as three separate articles in The T I A Newsletter issues of November, 1994, through February, 1995.

Part One: Basic Genetics
     Nicking, once considered a somewhat interesting theory worth no more than an occasional mention, has come to dominate Thoroughbred breeding to an extent dangerously out of proportion to whatever value it may offer. 
     Not long ago the owner of a stakes-winning mare retiring from the track told us he called a respected Kentucky bloodstock agent for help in deciding on a mate for her and the man said he couldn't make a recommendation until he could find out what score the nicking experts would give the prospective foal. 
     Soon after that, the manager of a major California farm told us that breeders calling for bookings to the most popular of their stallions don't ask about the horse's conformation, size, or temperament; they just ask about the nick. 
    Breeders everywhere beg to be told which stallions provide the magic nick for their mares and pay unregulated gurus to turn the key that unlocks the door to greatness. Purchasers of racing prospects increasingly rely upon nicking scores provided--often at substantial fees--by the high priests of the new religion. 
     Those nicking experts have become so powerful that, as noted above, even knowledgeable horsemen are prevented from freely implementing their informed decisions. 
    So many high-bracket buyers now depend on those nickmeisters that an unsatisfactory score can significantly decrease a horse's value and negate the efforts of horsemen with proven records of success. 
     All this has been made possible by the development of the computer--not so much the powers of the computer as the mystique of the computer. Consumers of the nicking products believe that if it comes from a computer, it must be right. 
    Forgotten is the cautionary phrase of the early days of computer development: garbage in, garbage out. Forgotten, too, are some of the most basic rules of traditional statistical research, especially those that demand adequate sample size and control of variables. 
     Perhaps most important, basic principles of genetics have been disregarded. 
     But the methodology of the nicking gurus is neither revealed nor examined. Their customers demand answers, not explanations; "it came out of the computer" is explanation enough. 
     For reasons to be discussed later, most nicks involve horses in the third or even fourth generations of the subject horse. Among the eight sires in the fourth generation of almost every Thoroughbred are famous horses who can be linked to create that prized nick. Reduce that to the four sires in the third generation and nicking combinations are dramatically diminished in number. 
     But what is the genetic influence of horses in those generations? 
     Horses in the fourth generation are, after all, the great-great-grandparents of the horse that is the subject of the nicking analysis. We need not challenge the validity of the basic theory of nicking to inquire as to the chances that that special something will force its way through the generational barriers to exert its magical influence. 
     That can be determined simply by applying the basic law of genetics that says that the maximum chance that a gene will be passed from one generation to the next is 50 percent. Even the most dominant of genes make it to the next generation only half the time. 
     Setting up the most favorable condition possible, that both sire and dam of the two nicking sires carried that magic gene, when that law is applied to a four-generation pedigree, the following probabilities emerge (if the sire and dam of the two nicking sires did not both carry the gene, the probabilities are one-half those shown below): 
     Fourth generation to third generation: 100 percent chance that the offspring will receive the gene. 
     Third generation to second generation: 50 percent of that 100 percent = 50 percent. 
     Second generation to first generation: 50 percent of 50 percent = 25 percent. 
     First generation to subject horse: 50 percent of 25 percent = 12.5 percent. 
     That 12.5 percent is not the fraction of the magical gene that the horse will carry. If the gene makes it all the way, it will be the entire gene. The statistical probability that the horse will carry that gene at all is 12.5 percent. 
     That's on one side of the pedigree. To activate the nick, a gene from the companion sire has to navigate the generational rapids down the other half of the pedigree, too. 
    That journey also has a 12.5 percent probability of success. But the chances that both genes, top and bottom, will survive the trip are not 12.5 percent. They are 12.5 percent multiplied by 12.5 percent, so the answer is 1.56 percent--one chance in 64. 
     That is the best possibility, assuming that the magical element of the nick is carried in just one gene. If it's necessary for a group of genes to be transmitted, the chances effectively would be zero. Since a horse carries thousands and thousands of genes, it's hardly possible that a nick could be made effective by the combining of a single gene from each of two sires. 
     Nobody knows how many genes would have to make that four-generation trip to create a significant combination, but it's impossible to believe that just one would do the job. 
     What if just six of those thousands of genes were required to trigger the nick--three from each of the two nicking sires four generations back? The chances that just three genes from each horse would carry across four generations to combine in the subject horse are 0.00038 percent. For comparison, on the same scale, here's the number that equals one percent: 1.00000. 
     In other words, the chances effectively are zero; going four generations back for nicks is a scientific absurdity. 
     If the nick is restricted to three generations rather than four, the probabilities are better, but still poor. In the final calculation 25 percent is multiplied by 25 percent (rather than 12.5 by 12.5) and the answer is 6.25 percent--one chance in 16. Even a two-generation nick provides no certainty that that gene will be transmitted on both sides of the pedigree. The probability there is just 25 percent (one chance in four). 
    The highest probability of all, of course, is the first-generation nick, matching the sire of the prospective foal with the sire of its dam. That translates to the first generation on one side and the second generation on the other (again assuming that the sires and dams of the nicking sires both carried the magic gene). The product of such a mating has a 50-percent chance of inheriting that prized gene (one chance in two). 
     The nicking process almost always bogs down at the first-generation level, though, because few sire/broodmare sire crosses have produced enough starters to permit the drawing of valid conclusions. 
     That introduces the major problem of sample size, which will be discussed in the second part of this series. 
     One provocative genetic question remains: What if that magic gene is passed on by a horse or horses other than one or both of the two nick-linked sires?  In the illustrations above, it is assumed that only those two sires carry the gene that activates the nick. 
    If the gene is carried by horses other than those two sires, the presumed nick could be activated even if the gene didn't descend from either of them. If the recipient of those wild-card genes raced successfully, the intended nick would get the credit even though the targeted sires weren't responsible. 
     The result would be the certification of a nick as successful when that success was the result of genetic accident unrelated to the nick. 

Part Two: Standards of Research
     Let's pretend that you have a friend with a farm and five stallions. His stallions aren't doing badly, but your friend wants to book more mares. He thinks that if he cut all the stallions' stud fees in half, he'd get a lot more mares and make more money. But he wants to test his plan before he makes the commitment. 
     So, to test his idea, he places an advertisement offering just one of the five at a reduced fee. The day after he places the ad, two runners from that stallion's first crop win stakes races. The following day, he gets two calls from breeders wanting to book mares to the horse. Later that same day he decides that his plan has worked and places another advertisement reducing the stud fees for his other four stallions. 
     Watching all this, you're surely thinking: 

         a. He doesn't know whether it was the stud-fee reduction or the two stakes winners that prompted those people to book  their mares. His test was a failure. He can't interpret the results. 
         b. Two telephone calls is not enough on which to base such a decision. There may be no more. 

     This fictional exercise illustrates two basic principles of research: stabilizing variables (that's "a" above) and obtaining large enough samples to support generalizations (that's "b"). It's hard to believe that anyone would think this make-believe stallion owner acted sensibly, but customers of the nicking merchants accept--and pay for--the same kind of bad science. 
     In the language of science, our friend did not "stabilize the variables." He couldn't tell whether it was the price reduction or the stakes winners, or both (or even something else) that brought in the bookings. 
    But in the Thoroughbred game, variables abound. As everyone knows, all mares are not alike. Their female families can be different, their race records can be different, their produce records can be different, their conformation can be different, and their temperaments can be different.
     And that's not all. 
     Racehorses have different trainers, different owners, and generally different care and experiences. 
     As far as nicking analyses are concerned, the only thing that counts is the mare's sire line. All those other factors have no bearing on whether the nick is certified as successful or unsuccessful. 
    All those variables are ignored in nicking analyses. Even though many different elements contribute to the success or failure of a racehorse, a nicking analysis is able to consider only the sire lines. 
     The towering question, then is this: Which element--or elements--was responsible? The claim that it is always only the mixture of sire lines is both insupportable and irresponsible. 
     Flowing alongside that question is another: sample size. 
     How many runners does it take to establish a nick as either a success or a failure?  Putting the question in another context, how many starters does a new sire have to have before we are confident that their performance will be typical of the performance of his future runners? 
     Would you have to see five runners before booking your mare to an unproven horse? Ten? Fifteen? Twenty?  Maybe 20 aren't enough. Surely five, or even ten, are not. 
     With that question in mind, consider nicking information from the Thoroughbred Times Buyer's Guide for the 1994 Keeneland July yearling sale. 
     Of the 287 yearlings in the catalog for that sale, almost half--131--were the result of sire/broodmare sire crosses without a single runner to the track. 
     Another 45 had been tried by just one starter, 29 with two, 14 with three, 13 with four, and 11 with five. 
     That's 243 of the 287 yearlings in the catalog--84.7 percent. Only 15.3 percent were from sire/ brood mare sire nicks that had been tested by more than five runners. 
     The Buyer's Guide nicking report then moves down to the next level--sons of the male-line grandsire crossed with the sire of the yearling's dam. Even that significant move back into the pedigree yielded only 168 nicks with more than five starters-- just 58.5 percent of the yearlings in the catalog. 
    The third level in the Buyers Guide nicking section, sons of the male-line grandsire crossed with the grandsire of the yearling's dam, still found 69 nicks with five or fewer runners and 97 with ten or fewer. 
     Even though they yield larger samples, those moves backward into the pedigree carry their own hazards, as was detailed in Part One. 
     (It is to the credit of the publishers of the Buyer's Guide that they made no recommendations on the basis of those statistics. They simply provided the raw information.) 
     This analysis of those Keeneland yearlings' pedigrees demonstrates the statistical difficulty of proving the value of nicks. To summarize, the combination of (a) the impossibility of determining the factors responsible for a runner's performance and (b) the absence of racing samples of acceptable size reduces the whole nick-evaluation process to a kind of interesting parlor game. 
     It certainly isn't science. 

 Part Three: Summary and Conclusions
    When the current nicking craze was in its early stages, one of the most acclaimed crosses was the mating of the stallion Secretariat with mares sired by Crimson Satan. From its first six runners to the track, that nick produced three stakes winners, two of them multiple winners of graded races.
     Now, several years later, the certification of the Secretariat/ Crimson Satan cross stands as a textbook example of the failure of nicking practitioners to observe and follow basic principles of scientific research. 
     At the end of 1985, that nick had produced--from those six starters--the major stakes winners Terlingua ($423,896) and Pancho Villa ($596,734) as well as Satan's Secretary, winner of unrestricted stakes at River Downs and Thistledown. 
    Now, nine years later, that nick has produced 13 starters, and those same three stakes winners. Three stakes winners from 13 starters is an excellent record, but it's not nearly as good as three stakes winners from six starters. 
     Putting it in formal terms, a sample of six runners was too small to permit a valid generalization. In all likelihood, 13 is also too small. 
     Therein lies one of the serious weaknesses of the analyses now being generated by nicking merchants all over the country--the lack of samples of adequate size. 
     It is instructive to note that, according to an article in the January issue of The Horseplayer Magazine, in creating his respected handicapping figures, Andrew Beyer used only information based on samples of at least 30 horses. 
     That contrasts sharply with nicking analyses that routinely accept samples of ten or fewer. The dramatic difference between Beyer and the nickmeisters is that it was of paramount importance to Beyer that his numbers be as accurate as possible. He couldn't afford sloppy research. 
    At the beginning, he was going to the track and betting his own money to test his system. For that, he required data in which he could have confidence. 
     Even more serious than the problem of sample size is nicking analyses' absolute inability to meet the primary requirement of scientific method--the stabilizing of all variables except the one being tested. To qualify as anything more than semi-educated guesses, these analyses would have to be applied to data in which all elements were identical except the sire cross being evaluated. 
     The Secretariat/Crimson Satan nick provides a dramatic example of the effect of failure to meet that scientific standard. All Crimson Satan mares are not identical. That fact, as obvious as it is, is ignored in the certifying of the Secretariat/Crimson Satan nick as successful and deserving of duplication. 
    The two best products of that cross, Terlingua and Pancho Villa, are out of the same mare, Crimson Saint. 
     Crimson Saint, bred to Secretariat, produced those two stakes winners plus a Fairplex Park stakes-placed earner of $154,788. Crimson Saint, bred to Nijinsky 2nd, produced Royal Academy, a Group 1 stakes winner in England and winner of the Grade 1 Breeders' Cup Mile in the U. S. Crimson Saint, bred to Nijinsky 2nd, produced Encino, third in the Grade 2 Hollywood Juvenile Championship. Crimson Saint, bred to Alydar, produced Alydariel, winner of a restricted stakes race at Los Alamitos. 
     The indisputable fact is that it is impossible to know whether the Secretariat/Crimson Satan nick was responsible for Terlingua and Pancho Villa or whether they were simply the result of mating a high-quality mare to a high-quality stallion. To this day, the Secretariat/Crimson Satan nick has produced only four stakes horses, and three of them were out of Crimson Saint. 
     No reputable scientist could look at this information and conclude that it proves that Secretariat/Crimson Satan is a "successful nick." A reputable scientist could conclude only that nothing has been proved other than that Crimson Saint has been an outstanding producer. 
     No one needed a computer to figure that out. 
     But the mare is only one of the elements involved in the creation and development of a racehorse. The quality of care that a young horse receives in its early years and the quality of training and opportunities it receives at the racetrack may be at least as important. 
     To pretend that all these variables are the same for all horses is to ignore the basic rules of scientific research and render worthless any conclusions reached, no matter how attractively packaged they may be. 
     Since it is absolutely, permanently impossible for a nicking analysis to hold constant all the elements that go into making a racehorse--except those two sire lines--the only conclusion that can be drawn is that nicking analyses are more likely to mislead than to enlighten. 
     That is an audacious assertion, considering that the sale of nicking analyses has become a major industry, with its practitioners becoming not only wealthy but also respected as the pre-eminent authorities in the creation of superior racehorses. But this writer is not the first to note the flaws in the methodology of the nicking merchants. 
     Dr. Steven A. Roman, creator of the Roman Dosage Index, made many of the same points in an unpublished paper titled, "Breeding Theories and Statistics." In the introduction to his lengthy paper, which he has made available to us, Roman makes this observation about what he calls "the currently fashionable notion of nicking": 
     "[It is] an idea that seems attractive on the surface but upon critical examination 
has . . . a questionable scientific basis and may be subject to gross misuse when accepted at face value." 

     The problem of sample size noted above is described by Roman in this way: 

     The concept of two bloodlines . . . having a unique compatibility is quite appealing because the decision- making process is made that much easier. The fundamental problem with individual nicking patterns . . . is that only rarely are there enough examples to provide a statistically significant sample size. By statistically significant we are referring . . . to the established criteria that afford a meaningful confidence level where the observed pattern has only a small probability of being a random 
event. . . .
      Ten or 20 or 30 specific examples of a cross between [two sires] may still not be sufficient to establish statistical significance. . . . Bloodline compatibilities are statistically meaningful only in terms of large populations and to that extent are useful in assessing trends in bloodlines. Individual nicking patterns almost never meet the criteria for statistical significance [emphasis added]. 

     When samples are too small--as they almost always are--the nicking analysts either ignore the problem or move back a generation or more in the pedigree. Regarding this practice, Roman comments: 

     Using any other representative of a bloodline as the basis for the compatibility of another member of that bloodline is a dangerous practice because with each succeeding generation there is a significant dilution of the genetic relationship between the two. . . . 
     Barrera is not Mr. Prospector even though both are sons of Raise a Native. Wajima is not Secretariat even though both are sons of Bold Ruler. Anyone who believes a Barrera/Wajima foal represents the same nicking significance as a Mr. Prospector/ Secretariat foal had better go back to basics. 

     Since it is impossible for these nicking analyses to meet even the most rudimentary criteria for scientific research, why are they so popular? Roman suggests the answer when he says that the use of nicking makes the decision-making process easier, but there's more to it than that. 
     Most of all, people have embraced nicking because it offers certainty--or, more correctly, the illusion of certainty. As presented by its purveyors, nicking offers the certainty provided by scientifically developed information derived by sophisticated computerized technology from a vast database of racing and breeding statistics. 
     Such information is offered not as some individual's opinion but as the result of impartial, objective scientific research. 
     Best of all, the answers are simple, clear, and unambiguous. No one appears to consider the possibility that they also could be wrong. 
     As was detailed in the second part of this series, 131 of the 287 yearlings in the 1994 Keeneland July sale were the result of sire/broodmare sire crosses untested by even a single runner to the track. Without a move back at least one generation in the pedigree, a nicking analysis can produce no honest answer other than "insufficient data." 
     Even a move back in the pedigree, to a match of sons of the yearling's grandsire with the sire of the yearling's dam, found only 168 nicks tested by more than five starters--only 58.5 percent of the yearlings in the catalog. Beyond question, any move backward in the pedigree reduces the validity of the result of the inquiry. The quality of the conclusion necessarily is degraded. 
     Yet untold numbers of buyers at the sale paid significant sums of money for rankings of those yearlings purportedly based on nicking analyses. In at least one case, those rankings were meticulously divided into a dozen or more levels, separating the prime prospects from the not-quite-so prime prospects. 
     Considering the absence of first-generation tests of those nicks--and often second-generation as well--the only legitimate nick ranking for the majority of the yearlings in that sale was "No ranking." 
    The appropriate response of sellers of nicking information would have been to refuse to accept payment for ranking those yearlings. Whether any of them did is not a matter of public record. 
     If the nicking mania were just an individual matter affecting only those who believe in its theories, only breeders and buyers directly involved would be harmed. But the nicking merchants have gained such power over buyers of racing prospects that sophisticated, experienced breeders are being forced to modify their mating plans to conform with the sale recommendations of the nickmeisters. 
     And though it's never talked about, there always exists the possibility that the recommendations of a nicking merchant might be influenced by payments from a stallion owner, sale consignor, or some other party who might profit from a favorable report. 
     At present, the industry has no mechanism of any kind to evaluate the quality of the nickers' products, to verify their claims, or to expose possible conflicts of interest. 
     Industry publications meticulously research claims by stallion owners and sale consignors before accepting their advertisements. Yet those same publications print advertisements by nicking merchants making unverified--but always impressive--claims of success. 
     Whether those who follow the calls of the nicking sirens deserve our pity or our scorn, the industry as a whole is the victim of the nicking mania. Despite the claims of its supporters, the most likely result of their reliance upon nicking as a primary mating criterion will be the breeding of poorer racehorses than would otherwise have been the case. 
    Excluding otherwise desirable stallions from consideration and including less desirable ones purely on the basis of nicking analyses inevitably will lead to the producing of less capable runners. 
     In the long run, the problem will solve itself. Breeders and buyers who rely on nicking recommendations will be unable to compete successfully with those who don't. For the present, however, responsible members of the Thoroughbred community must stand up and defend legitimate practices rather than tolerate--and sometimes even honor--those who subvert them. 

    Editor's note: For his assistance with the genetic calculations cited above, we wish to thank Dr. Bo Belhage, associate professor in the Institute of Biochemistry and Genetics at the University of Copenhagen, Copenhagen, Denmark. 
    Our thanks also go to Dr. Steven A. Roman of Richmond, Tex., creator of the Roman Dosage Index, for granting us permission to reprint portions of his unpublished paper analyzing computerized nicking research practices.