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5 Things You Should Know About Thoroughbred Nicking

If you're not completely familiar with the basic premise of sire-line nicking, here it is in a nutshell: 

Specific affinities of stallions of one male line for mares from other sire lines -- called nicks -- have made a profound impact on the development of the Thoroughbred. Today's powerful data-processing computers have now made it possible to measure and rate nicks.

But what should you really know and consider when investigating the nick rating of any potential purchase or mating?

  1. Nicks are a solid predictor to racetrack success -  The TrueNicks calculation was developed based on a study of 100,000 horses, with the calibration of the scores generated showing a very strong correlation between the highest variant scores and racetrack success. This point alone should not be underestimated. As far as we are aware, no other pedigree theory (The Rasmussen Factor of inbreeding to superior females, Bruce Lowe's Thoroughbred family studies, line-breeding to full relatives, etc.) has undergone such scrutiny and emerged with a measurable positive correlation.

  3. Nick ratings change - In general, sire lines continue to breed to the successful patterns that they have previously established.  As an example, Fappiano did well with mares by In Reality; his son Unbridled had success with mares by both In Reality and his sons; and, in turn, his son  Unbridled's Song has done well with later generations of In Reality-line mares.

    This pattern can vary over time, when a sire line alters its functionality and finds itself in an environment where commonly-found bloodlines cause it to excel or fail.

    TrueNicks ratings are recalculated every day to take into account new foals, new starters, and new stakes winners. This ensures that breeders and buyers have the latest information available when considering their mating plans and purchases.

    Despite the continual updating of information (and the resulting minor adjustment of the variant score for a particular cross), once a TrueNicks rating has been established, it generally takes several significant events for it to change rating bands (i.e., letter-grade scores).For a rating to change dramatically in a short time period, a drastic change in the quality of individuals produced on a cross would have to occur within a large group of individual horses over a small amount of time -- an unlikely occurrence.

  5. There are "ratings" and then there are "ratings" - When developing the TrueNicks system, we had already reviewed other pedigree rating products on the market. The proprietary TrueNicks algorithm sets it apart from its competitors, and offers owners, trainers, and breeders a genuine and measurable edge when it comes to making breeding and purchase decisions.

    The first major difference between TrueNicks and other programs is that because we are using a complete data set to generate the rating -- we pull from the official records of The Jockey Club Information Systems -- TrueNicks reflects the true opportunity of any hypothetical cross.

    The problem that can occur with systems that base calculations on hypothetical opportunity -- where they are using a subset of stakes winners instead of a complete database of foals -- is when specific crosses are tried either more or less often than they normally would hypothetically occur. Kingmambo (TrueNicks,SRO) when mated to Sadler's Wells mares is a perfect example. Kingmambo stands here in America, and Sadler's Wells is a broodmare sire whose daughters are primarily based in Europe. The nick initially had a couple of high-profile horses, creating a situation where that cross was subsequently tried an extraordinary amount of times. Products that are calculated on hypothetical opportunity can't adjust for this type of occurrence; their data is incomplete and therefore less meaningful. Because TrueNicks factors how many times each cross has actually been tried, our results reflect reality better in those cases.

    More simply:  it is easy to count successes alone, but considering failures as well yields a more realistic number. What is sometimes initially perceived as a downside to that is TrueNicks generates a lot of low ratings. In doing the beta testing and subsequent calibration testing, it was readily apparent that to get a B or an A on TrueNicks is quite difficult - the system doesn't just spit out A's and B's like confetti. You are going to see a lot of Ds and Cs -- and even Fs -- when using TrueNicks, but those grades realistically reflect the history of a given cross.  Remember that TrueNicks measures the strength of the cross, not the strengths of the sire's or dam's pedigrees.

  7. Nicking reports need to be interpreted - The TrueNicks rating consists of both a variant score and a letter-grade rating (similar to the academic system). It is important to understand that the variant rating scale is not linear, so while a below-opportunity rating will have a variant of 0.001 to 0.99, an above-opportunity rating can have a score from 1.01 up to numbers as high as 500.00 and beyond. Generally, extremely high scores are the result of a mating that has had considerable success with limited opportunity.

    The best guide to the potential success of the nick is the letter ranking which has been evolved through careful study of the relationship between the general population and the stakes-winning population. To allow usersto get a better grasp of the system, rather than just giving the raw variant numbers, we have banded those numbers from A++ all the way down to F. By and large, horses that are rated A and B are outperforming the rest of the population by a considerable margin. In layman's terms, a B+ or better is probably where you want to start to think, "This is a solid mating."

    One of the unique features of TrueNicks is a list of the five best horses bred on the given cross, whether they're stakes winners or not. TrueNicks is a system that is designed to encourage intelligent interpretation.  We would not wish to see breeders blindly using ratings without looking at the context in which they're formed, which includes researching the best horses bred on the cross. Ideally, TrueNicks reports are used to supplement information from additional reports and research, and breeders look at the whole pedigree and interpret the data.

  9. Nicks alone are not "THE ANSWER" - Nicks are are not the silver bullet, the magic answer, the panacea to everything to do with Thoroughbred breeding and racing. (You can quote us on that.) The reality is, no pedigree rating system in the world has all the answers. No matter which breeding theories you follow, always remember:  "Paper doesn't run very fast."

    When planning or evaluating matings, factors such as a balance of aptitudes (speed, stamina, preference for dirt, turf, or all-weather tracks), inbreeding, line-breeding, and outcrossing and -- most importantly -- conformation must be considered. TrueNicks is an important tool to be used by the Thoroughbred breeder and owner because it identifies crosses that have had above- or below-average success in previous attempts -- the tool is valuable only when given appropriate weight and considering all other factors that influence eventual racetrack performance.

What are your thoughts on Thoroughbred sire-line nicking? If you have any more questions about nick ratings, or want to make a comment on what we have posted above, please feel free to do so in the comments section below. Alan, Byron, or the rest of the TrueNicks team will be happy to respond.

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Nicking is a very interesting subject and as a person who loves to follow pedigrees the question of nicking is an important one. I believe that what we must be careful of is if the nicking becomes inbreeding. It seems that we tend to overdose on one or two lines to the point that it is very prominent on both sides of the pedigree, if one side of the pedigree is already heavy with let's say the Northern Dancer/Mr. Prospector cross then I believe that the other side should then either be completely free of either line or one line sire must be far enough back to not produce inbreeding as this could possibly bring up bad faults rather then the good (speed, stamina, attitude). I believe that we must continue to study the effects of nicking, inbreeding and line breeding so that we may breed what's best from horse to horse and to see what contributes to bringing out the worst.

Julie L. 24 Sep 2008 3:30 PM

thanks, very helpful.

kerry 24 Sep 2008 4:04 PM

This is an incredibly interesting topic, but until you actually provide some details on how your ratings are calculated and the exact design of your studies that are supposed to validate its predictive power, I'll have a very hard time taking it seriously.

Alex 24 Sep 2008 4:41 PM

How many generations do you reach back to get a rating?  I did a rating with a stallion and my mare and got a "Not Rated" or something along those lines, even though it seemed possible to get some sort of rating.  Thanks!

  • TrueNicks reply:  Thanks for your question.  To assign a rating, the TrueNicks system requires a degree of statistical significance in the number of times a cross has been tried.  When a cross has not been tried at least 15 times going all the way back through the fourth generation of both sire and broodmare sire, the assigment of "No Rating" lets you know that you're in rather uncharted territory.  The "5 best horses bred on this cross" section is often revealing in these circumstances.  To learn more about the "No Rating" classification, please visit the FAQs.
LittleGuyBreeder 24 Sep 2008 6:43 PM

How does the TrueNicks rating compensate for the number of generations from the offspring to the selected male ancestors? Are the ratings for matings where the two stallions appear in the 2nd generation more accurate than if they were to appear in, say, the 2nd and 4th generations? Since each breeding is a unique recombination of the genetic material, wouldn't there be considerable dilulution with the increase in number of ancestors between the prospective foal and the selected stallion? Wouldn't the pedigrees of the mares have an equal impact to that of the stallions? Whew ... I enjoy reading your analysis, thanks.    

  • Alan's responseThank you for your question: Overall there would be a tendency for there to be a higher degree of certainty with nicks based on ancestors that are close up in the pedigree. In mathematical terms, the percentage of the pedigree contributed by sires in the third and fourth generations is relatively small. However, that is not the whole story. Almost all stallions that continue sire lines are superior performers. By definition, their dams had a genetic affinity with their sires. As a consequence there is a tendency for them to cross in a similar way to their sire (although on occasion there are modifications, such as Point Given crossing well with Seattle Slew, a horse who has an affinity with Point Given's broodmare sire, Turkoman - a situation that TrueNicks was able to very quickly recognize). An example would be Fappiano and In Reality. This was a highly successful cross, and has continued to flourish with Fappiano's son, Unbridled, and his grandson, Unbridled's Song.
    This tendency for stallions to throw in a somewhat similar way to their sires in effect absorbs the contribution of the distaff side of the pedigree. To put it in algebraic terms: if stallion A crosses well with mares by both B and C, then a stallion bred on an A/B cross will probably do well with mares by C, and a stallion bred on an A/C cross will probably do well with mares by B.

    Byron's response:  Michael, interesting question. It actually inspired me to go back and take a look at the logic rules that we set up as well as the data from the study of 100,000 horses that we based the TrueNicks score on. The most popular "rule" to make a calculation on (TrueNicks has some unique thresholds that need to be met to ensure integrity of the ratings returned) is unsurprisingly "The Grandsire and his sons, when mated to mares by the Sire of the Broodmare Sire and his sons". Thinking logically you can probably appreciate that this is the most popular. Interestingly there is no bias when it comes to any one rule reflecting a greater percentage of the stakes winning population than it should. The most popular rule has proportionately the same number of stakes winners as some of the less popular rules that TrueNicks is calculated on.
Michael DuSchane 28 Sep 2008 11:34 PM

As a regional breeder, we are left guessing: sons and daughters which are bred from more prominent stallions, and from mares by prominent stallions, have inherited only half the predictability which your nicks are based upon.  Again, we are left with "5 best horses on this cross", but it really is only "2 1/2 horses".  Any suggestions?

  • Alan's response:  Thank you for your question: if I understanding your question, you are looking at a situation where you might have a regional based stallion - let's say a minor winning son of A.P. Indy - crossed over a mare by one of Mr. Prospector's less prominent sons, and comparing it with the rating one might get if one crossed A.P. Indy himself with a Mr. Prospector mare. Firstly, TrueNicks - unlike other prominent nicking programs - include all horses deemed eligable for black-type by the International Cataloging Standards Committee. That means any state-bred or restricted stakes winners by our hypothetical son of A.P. Indy out of mares by the hypothetical son of Mr. Prospector (and if appropriate, other Mr. Prospector line mares would be taken into consideration) as would other A.P. Indy (and if appropriate Seattle Slew) line stakes winners out of mares by the hypothetical son of Mr. Prospector. This feature greatly increases the usefulness of TrueNicks to breeders in a regional program.

    If, however, the cross of our hypothetical A.P. Indy son over mares by our hypothetical Mr. Prospector son, or variations included these indivduals has not generated enough stakes winners or runners to calculate a valid rating, the calculation would default to a calculation based on sons of A.P. Indy with Mr. Prospector line mares.

    It is true that in percentage terms in the case of a son of A.P. Indy with a mare by a son of Mr. Prospector, A.P. Indy and Mr. Prospector comprise 50% less of the pedigree than when A.P. Indy is crossed with a Mr. Prospector mare. That, however, is not the whole story. There is a very marked tendency for stallions to continue to cross well with similar strains to their sire, and this can often be observed over several generations. Thus, our hypothetical son of A.P. Indy will probably tend to cross better with mares by sons of Mr. Prospector, than, for example, by sons of Halo.

    I would also point out that -- because TrueNicks includes all stakes winners -- the owner of the sire or dam in question in the "son of A.P. Indy over a mare by a son of Mr. Prospector" example is in no different a situation from a breeder considering sending a mare well-bred mare by a son of Mr. Prospector who is unproven as a broodmare sire (say Aldebaran) to a mare by A.P. Indy's unproven son Bernardini.

    In either case, the "Five best horses bred on the cross" will still be the five best horses sired by A.P. Indy and his sons out of Mr. Prospector-line mares, and investigation of them by well provide other useful information as to specific influences.

Michael Martin 02 Oct 2008 12:37 AM

Alan and Byron, I enjoyed reading your responses, they gave me insights I had not considered. Thanks

Michael DuSchane 02 Oct 2008 11:20 PM

my first jump into the breeding world maybe is not the best but I breed mares by el corredor grand sland lemon drop kid and wheaton with horse by grindstone I like your opinion on my crosses

william 10 Oct 2008 1:54 AM

as a student of breeding and confirmation, your true nick is a invaluable tool. however, it would be even more invaluable if you were to allow the subscriber to simply type in the name of a mare and get the best crossess as opposed to having to type in each stallion individually.



  • Byron's Reply: Fred, thanks for the comment. We are really pleased with the market acceptance of what we believe is the best pedigree analysis program available in the business. We have a broodmare analysis product in the works that will allow you to both search for stallions by service fee and manually enter stallions to run against your mare...stay tuned!
fred heyman 11 Oct 2008 9:13 AM

Hi Alan & Byron,

I recently conducted a TrueNicks experiment. We have three foals, all out of the same mare. The sires are sons of Storm Cat, A.P.Indy and Danzig, the first two are out of Mr.P mares, the third is out of an Alydar mare. In an effort to quantify the mares contribution I crossed the first and second dams of the foals with the three stallions and their dams sires. This gave me four factors for each foal which I averaged and applied to the TrueNicks numerical grid. The resulting scores were A, B and A+. The actual TrueNicks scores are C, C+ and A++. Please comment on this approach, I don't know how valid these (TrueNicks 2.0) scores are but I certainly enjoyed the exercise...haha Thanks    

Michael DuSchane 18 Nov 2008 10:06 PM

hi there! i am jun, a horse owner / breeder / trainer in the philippines.. i recently browsed your site and was interested trying out hypothetical foals for US thoroughbred horses.. i was wondering.. do you know any sites that gives something like this using philippine thoroughbred horses.. just wondering you know.. haha! thanks!

  • Scot's reply:  TrueNicks reports are available for all registered Thoroughbreds -- the data are pulled from the database of The Jockey Club Information Services, so is a true international product.
jun 03 Jan 2009 6:57 PM

Alan Porter identifies cases where a poor overall sire line affinity can be improved by other pedigree patterns -- a process aided by additional tools included on the TrueNicks report page.

TrueNicks 11 Mar 2009 3:48 PM

I was wondering if there is a place to type my mare in and have it cross refercnce with the best studs avaible

John Groen 03 Mar 2011 6:50 PM

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