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A Classic Case of Coincidence?

The interpretation of Thoroughbred pedigrees is no simple matter. The multi-factorial elements that might be considered include nicks, inbreeding, linebreeding, the positions of ancestors relative to one another, the relationship of the pedigree to the female line, and the class of the individuals involved.

Given the volume of the data, and the difficulty of reducing much of it to simple paradigms—even the TrueNicks rating, considering just one aspect of the pedigree, requires a complex algorithm; the entire database of The Jockey Club Information Systems; and considerable computer power to achieve its output—it's not surprising that pedigrees are often viewed as being rather random and chaotic, especially when the above factors are overlaid with genetic variability (the differences in ability and aptitude that can occur even with full siblings, let alone with other close relatives). That, however, is not our view, although we'd agree that patterns and paradigms are so complex that they can easily seem random (similarly the patterns of protein sequences on a strand of DNA are so complex that they were thought to be random, until artificial neural networks were brought to bear on the problem around 25 years ago).

While some might view it as nothing more than an article of faith, we'd also have to say that over 40 years of looking at pedigrees has engendered a firm conviction that certain types of crosses and pedigree patterns occur in good horses far more often than they should by chance. And although it's purely anecdotal, we were particularly struck by a two recent classic winners that appear to be a remarkable case of coincidence.

The first of these is Oxbow, who led virtually throughout to claim the Preakness Stakes (gr. I). What is notable here is that Oxbow's victory came less than 12 months after his very close relative Paynter (a Pedigree Consultants recommended mating), led for all but the last stride of the Belmont Stakes (gr. I) before returning to take the Haskell Invitational Stakes (gr. I) in a style of a potential champion.

Oxbow and Paynter are both sons of the excellent runner and sire Awesome Again (TrueNicks,SRO), and their dams, Tizamazing and Tizso, are siblings (that duo are also sisters to Tiznow (TrueNicks,SRO)). The sisters have so far produced eight foals of racing age to the cover of Awesome Again, six of whom have started, with Oxbow and Paynter being joined as stakes winners by Oxbow's brother Awesome Patriot, a stakes winner who is also graded-placed. So that's a 50% stakes winner to starters strike rate, with one being a classic winner, and another being a near classic winner and spectacular grade I scorer.

It's likely that the inspiration for the cross that led to Awesome Patriot, Paynter, and Oxbow was the superlative Ghostzapper (TrueNicks,SRO), who was by Awesome Again out of a mare by Relaunch, the paternal grandsire of Tizamazing and Tizso. Oddly enough, however, although the Awesome Again/Relaunch cross is responsible for Ghostzapper, Paynter, and Oxbow—who along with Game On Dude would be considered three of their sire's best four sons—when we remove the sextet produced by Tizamazing and Tizso, we find that Ghostzapper is the sole stakes winner from 37 other runners by Awesome Again out of Relaunch-line mares. When comparing Tizamazing and Tizso to Baby Zip, the dam of Ghostzapper, we can note that their granddam, Sleep Lonely, is by Pia Star, who is by Olympia (by Helipolis out of a mare by Mahmoud, a Blenheim II/Gainsborough cross), from mare by a son of Tom Fool, and that Baby Zip is out of Thirty Zip, whose sire Tri Jet is by a son of Tom Fool, out Haze, who is by Olympia out of Blue Castle, another product of the Blenheim II/Gainsborough cross. As as a result Baby Zip has a rather similar background to Tizamazing and Tizso.

It was such nuances that, in part, drove the creation of the TrueNicks Key Ancestors Report, a product that considers the whole pedigree, searching the entire Jockey Club database for mares with similar backgrounds to the subject mare.

Oxbow and Paynter are, in the conventional sense, very well-bred horses. The same couldn't really be said for Meisho Mambo, who this weekend took her record to four wins in seven starts with a victory in the Yushun Himba (Japanese Oaks, Jpn-I). Her sire, Suzuka Mambo, was a talented son of Sunday Silence, winning the Tenno Sho Spring (then a Japanese group I, but not recognized as so by the international cataloging standards), but Meisho Mambo is the only stakes winner to appear from 177 starters in his first three crops. A look at the distaff side of the pedigree reveals that none of Meisho Mambo's first five dams produced a black-type winner (only one produced a black-type horse), and that prior to Meisho Mambo the only other stakes winner under the first four dams was the minor black-type winner Meine Ratsel (who is by another Sunday Silence horse, Stay Gold, and has Meisho Mambo's fourth dam as her third dam).

The "coincidence" here is the relationship between Spring Mambo, the dam of Suzuka Mambo, and Meisho Mambo's stakes-placed granddam, Meisho Ayame, who prior to Meisho Mambo was the only black-type performer to be produced by the first five dams. Spring Mambo is by Kingmambo (by Mr. Prospector out of the fabulous Miesque, a daughter of Nureyev) and out of a daughter of Nijinsky II. Meisho Ayame is by Jade Robbery (by Mr. Prospector out of a Nijinsky II three-quarters-sister to Nureyev), so very closely related to Spring Mambo. The relationships don't stop there, as Suzuka Mambo's granddam, Key Flyer, is a Northern Dancer/Graustark cross, and Ameriflora (dam of Meisho Mambo's broodmare sire, Grass Wonder) is a Northern Dancer/His Majesty (brother to Graustark) cross. We'll conclude by noting that Grass Wonder is a son of Roberto, a horse whose dam is closely related to the dam of Mr. Prospector (who is here twice). Overall this pedigree serves as another example of what we see time and time again: an under-performing pedigree is upgraded by close inbreeding to genetic relatives.

Incidentally, the TrueNicks Key Ancestors Report with Analysis for Meisho Momoka (dam of Meisho Mambo) is particularly interesting here, recommending several similar matings with Japanese sires, including Stravinsky (by Nureyev with a second dam by Mr. Prospector), Fasliyev (by Nureyev out of a Mr. Prospector mare), Bago (whose dam is a Nureyev/Mr. Prospector cross), and Kingmambo's son King Kamehameha (bred on a very similar cross to Meisho Mambo's second dam.

To sum up: we have one weekend, and two classic winners. One is out of a mare whose sister produced a grade I scorer and near classic winner, by the same sire, the sisters also having a background very similar to the dam of that stallion's best runner (and only stakes winner on the cross not out of the siblings). The second classic winner is by a sire who has no other stakes winners from 177 starters, from a family that hasn't produced a stakes winner for five generations. A classic coincidence, or a sign that complex patterns have an impact?

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 First of all, thank you, Alan, for using the word 'impact' correctly.

 I always become quite annoyed with people who say discount the possible influence of ancestors more than a few generations back.  If you look at Native Dancer's pedigree, there is only a single gray horse per generation for 17 generations back.  It isn't until the late 1700s that multiple grays appear and that 2 grays are actually bred to each other.

 Coat color is an obvious trait that is easy to follow.  Who knows what other genes have been passed down for many generations and when they will appear together in a horse.   Personally, I spend a lot of time counting up how often Nearco shows up through out a pedigree.

jean-in-chicago 29 May 2013 9:07 PM


Most population studies on the heritability of performance as a trait peg it at ~30-40%. This means that while the parents of a horse contribute 50% each (roughly), in terms of the trait of performance they are responsible for ~15-20% each of the variance of performance (half of the 30-40%). The grandparents are then ~7.5-10% and great grandparents ~3.25-5%. Once you start talking about names beyond that point, their impact in terms of performance as a trait recedes towards zero which is why people correctly discount the influence of distant ancestors. Coming at it a different way, statistician David Dink has come to a similar conclusion in his work. The names recess to the norm after three generations and are generally just noise.

That is looking at cause, it is not to say that distant ancestors aren't associated with performance. There is a difference between cause and association which gets lost in these types of discussions.

Byron Rogers 30 May 2013 6:22 PM

Much admired Alan's short, but important piece. Its general message should give pause to those who debunk the value of pedigree research. I suppose it was necessary to include those anecdotes, but doing so often adds fuel to the naysayers-for it's then so easy to offer anecdotes to the contrary (just imagine how more "convincing" yours may have been had Tiz Roses and All Tiz proved better runners)...A more thorough explanation of Alan's points would require books-as a matter of fact Alan has written a few on this very subject of patterns...At first, I felt it better not to engage in this discussion-Alan's piece was rather pristine, so why, perhaps, muddy the waters. But then I noticed Byron's comment, and while no doubt genuine, and authored by another learned source, may have in fact muddied the waters. I think the concept of heritability can be rather tricky and often misinterpreted in application. For example, the fact that "paper" pedigrees" may offer a relatively low % of performance predictability should not imply that the ACTUAL genes inherited offer the same degree of impact on performance-ex.: two full siblings share the same "paper" pedigrees, but can have quite different genetic compositions. Yes, the vagaries of intra and extra-uterine environment can substantially impact, but as these are today likely far better "controlled" I doubt their combined impact is in the range of 60-70%...As to Byron's distiction between "cause" and "association", I think, within this context, none exists. As somewhat an aside, our present understanding of genetics makes it entirely possible that a relatively distant ancestor could exert a meaningful contribution (+ or -) to performance. While it may be difficult, if not impossible, to employ this concept in present mating practices, should not negate this reality.  

sceptre 31 May 2013 12:26 PM

" Once you start talking about names beyond that point, their impact in terms of performance as a trait recedes towards zero which is why people correctly discount the influence of distant ancestors." Byron are you saying you beleive that Nearco in the 6th or 7th generration has 0 impact on term of performance. If you do than why key on a

ancestor in a report. Help me here. why did Alan mention the Blenheim II/Gainsborough cross. If it ment 0 in term of performance.

Obmar 01 Jun 2013 5:04 AM

This is not exactly the easiest stuff to concisely define, and it's a question of trying harmonize what we know about genetics and what we observe.

I would also stress the importance of "starting at the front" when considering a mating - that the sire and dam need to be a good match in terms of aptitude (depending on what you are hoping to breed), physique (phenotype), and temperament.

I also want to look at the TrueNicks rating, to confirm at minimum, that the cross has not been negative, and now the Key Ancestor report, which indicates what strains have and have't been positive influences for similarly-bred mares.

I'm also not advocating any kind of breeding theory as a substitute for class. I want to start with the best stock available.

Having said all that, I believe than inbreeding or linebreeding through similarly-bred channels often has an influence for upgrading (it's telling that a disproportionate number of generally disappointing stallions have done their best work when sent mares that give this kind of "clever" pedigree reinforcement).

I would also say that I would regard multiples of related ancestors further back in pedigrees than many are inclined to look, can exert a positive influence.

I guess the "tension" between genetics and observation comes when say that "all genes come from somewhere" - like the single source of Native Dancer's gray coat color - but note that any one ancestor in the sixth generation is likely to have contributed only around 1.5% to genetic make up of the foal.

So if we are going to seize on "Nearco in the sixth generation" and say that is why a horse is good - to credit one ancestor with as the source of a positive genetic variant, we're on dodgy ground.

However, it's not quite as simple as that. It's highly likely the difference between the elite and non-elite thoroughbred comes down to the additive effect of relatively small number of gene variants. In the human, there are about 200 different genes that have been associated with athletic performance, but given that the thoroughbred has been bred for performance for over 300 years (or 30+ generations), genetic variation in this regard is probably a lot less than it once was, a lot of positive traits have been fixed over the generations (remember, even a pretty slow thoroughbred would be an elite athlete compared to most non-thoroughbred when it comes to running over distances that a the norm for thoroughbreds).

What we call a "nick" would frequently be down to the sire and broodmare sire having genotype that gives a high probability of inheritance and expression of the maximum number of positive variants (and with those in harmony with the potential phenotype).

So if we have two stallions bred on a successful "nick"  it's very possible that they have inherited similar variants, and might cross well with mares from similar backgrounds. Thus, when we inbreeding and linebreed to successful "nicks" or other positive combinations, the chances of the positive variants that worked well together being transmitted are far higher than in a more outcrossed pedigree (at least as far as we can go from a paper pedigree). It's why, as we discovered with our original TrueNicks study, that the accuracy of the ratings doesn't drop off over the generations in the way one might expect. Not specific inheritance, but the tendency of the same things to go on working with the same things

It's likely that there might be optimal degrees of inbreeding and linebreeding - that not only maximize the chance of expression of the positive variants that a parent has, but also brings in positive variants that the parent lacks (where outcrossing will diminish the likelihood of reinforcement, and close inbreeding is likely to fix existing positives, but less likely to contribute "missing" ones).

So using our Blenheim II/Gainsborough example, can we say for sure that Paynter, Oxbow, Awesome Patriot and Ghostzapper - the four stakes winners bred on an Awesome Again/Relaunch cross - inherited any specific positive genetic variants from those specific instances. No, absolutely not. Do I think that the similarities - of which Blenheim II/Gainsborough are an integral part - have something to do with why those four horses - three out of the top drawer - are the only stakes winners for the Awesome Again/Relaunch cross. You betcha!

So, hard to attribute specific genetic variants for performance to any specific ancestor that deep into the pedigree, but easy to say such patterns are very often associated with success (although TrueNick ratings and Key Ancestor reports might frequently save us the trouble of having to dig them out). Where it gets a little more blurry is if you can ask whether the patterns have caused the "right" variants to come forward, even though they are not attributal to any one individual!

Alan Porter 04 Jun 2013 12:34 PM

The terms "inbreeding" and "line breeding" seem to get tossed around, almost interchangeably.

A statement was made regarding Flower Alley: "inbred X3 Mr. Prospector". Upon review of the page, it was noted that Mr. Prospector was in the top and bottom of the pedigree in the 3rd gen., while Northern Dancer was present in the top and bottom in the 4th gen.  This represents line breeding, NOT inbreeding. Inbreeding refers to extremely close crosses, such as colt/dam, something I've never seen in selectively bred Thoroughbreds.  "Inbreeding" is often misused.

MK Austin 04 Jun 2013 10:50 PM

MK Austin

Re: inbreeding and linebreeding. While the definition might not be the same as with most of the livestock world, the convention with thoroughbreds has become to call inbreeding a duplication or multiple instance of an ancestor within four generations, and linebreeding duplications or multiple instances at five or six generations. In fact if you look at any five cross pedigree generated by The Jockey Club through Equineline, you will see multiple ancestors listed as "Inbreeding."

Alan Porter 05 Jun 2013 8:00 AM


I had meant to reply to this earlier but I have just got back from a trip to Australia and getting over the jet lag.

This type of pedigree analysis is primarily where Alan and I don’t so much disagree, but diverge in opinion.

While I would be the first to admit that Alan has significantly more experience and success with breeding racehorses, unlike him, I give very little stock to anything that happens outside the third generation of a pedigree. I used to, but it just didn't stack up to statistical scrutiny. I am more of the “Big Data” Joe Estes/Tony Morris/David Dink type with the immediate ancestors providing much of the genetic merit of a given horse.

Most of the modeling that I have done with data to date gives significant weighting to the racing class of the immediate parents. That is no surprise to you. In the case where the racing class is unknown, as it often is with mares that are unraced, the model has created performance based relationships between the grandparents with the racing class of the broodmare sire and granddam of a foal being somewhat important in that respect. I have tried throwing in third and fourth generation performance data to see what impact it has on the performance of its descendant but the regression model kicks these data points out as being non consequential even when I think that there is not a lot of performance data in the first two generations to make a decision on (hence my thoughts about them just being names on a page).

That is not to say that pedigree relationships are not important. Alan sort of implied something that we have modeled that looks promising in terms of prediction and that is coefficients of relatedness (to 6 gens) and coefficients of inbreeding (to 8 gens) with hypothetical matings between immediate ancestors. One of the more interesting one is the hypothetical mating of the sire and the broodmare sire for instance (which leads towards nicks in general).

In the case of “full siblings” as you mentioned above, there are actually quite a few data points that really discriminate between their potential as racehorses. One of the more interesting ones is the “foal rank of the sire”, that is, what foal number was the foal in the sires career, was it the first foal born by the sire or the 752nd? That has a decent impact on the outcome. Zabeel just sired his 43rd individual G1 winner last weekend but for me the fact that he had 10% SW/Fls first 10 crops but from his current 3yo, 4yo and 5yo crop he has 226 foals with just 7 Stakes winners (3.5% SW/Fls) tells me something and it is not related to the quality of mares that he covered. Ditto, but less influential is the foal rank of the mare.

Alan was talking about writing something further on all of this which would be interesting to further this discussion.


Byron Rogers 09 Jun 2013 9:08 AM

Hi Byron,

Very nice of you to respond, and I hope you enjoyed your trip. You offer several interesting observations, and allow me to discuss a few:

When you say third and fourth generation "performance data", should I assume you're referring to the specific racing performance data of those influences, i.e. (ex.) Buckpasser appearing in the 4th and his earnings/start, etc.--rather than the data related to him as a sire, etc.? No doubt the data related to the latter would be a far more cumbersome, if not impossible task, but likely far more relevant. So, let's take a look at Tapit's pedigree, and his Foggy Note. I think you're suggesting that Foggy Note has little if any impact on Tapit's success as a stallion. I can't PROVE otherwise, but I stongly suspect it does-and not just by ASSOCIATION.

My very strong guess is that the variability of (gene) inheritance among full-siblings is the central cause for the disparity, and not "foal rank of the sire". That said, you're alluding to chromosomal aberration as a cause-i.e. the older the stallion, the greater the liklihood for chromosomal aberration and its negative effect on outcome. I think the jury's still out on this, but I've suspected as much-for some stallions more than others (Raise A Native and Tom Rolfe come readily to mind).

Much of this debate centers around one's personal (life-long) observations vs some statistical studies. So, which better mirror reality? Before you embrace the latter (statistical studies) perhaps  better first scrutinize those studies.      

sceptre 10 Jun 2013 2:51 PM

Startling in the concept and astonishing in its aspects is the recent breeding premises of a renowned scholar, Dr. William C. Boyd, Author and member of the faculty at Boston University of Medicine. Dr. Boyd a recognized authority on genetics and Physical Anthropology has offered up a breeding principle which, If true, makes a virtual farce of millions of words of turf literature for a century; he make the breeding student who pores over the lineage charts a chump and a fool; and make those of us who believe in the blood of broomstick, Domino, and *Teddy the subject of a colossal guffaw. Dr. Boyd states alas, that recent studies have shown that an individual horse or human my not inherit even a single chromosome from its grandfather and that the chance of inheriting this single chromosome from his grandparent is 1 in 8,388,608. Now as we see it, the fact that scholar Boyd admits, by implication, that a chance does exist, even though one in eight million, that a Citation say, can get a chromosome from his grandad Bulldog.


Obmar 11 Jun 2013 4:43 AM


I haven't read your Dr. Boyd's paper, but can say with absolute certainty that your interpretation/application of its message is incorrect. While it is nearly impossible to inherit a 100% COMPLETE chromosome from a grandparent, etc.-owing to crossing over, etc., it is extremely likely that a goodly amount (on average, appox. 25%) of each grandparent's chromosomal material will be inherited by the grandchild. I suggest you do some more reading.

sceptre 11 Jun 2013 2:05 PM


Correct. The performance data related to their racetrack performance. The production related data for the sire and dams in that generation wasn't easily done as you had horses born where the sire data for the grandsire, let alone the sire, was still developing so that "point in time" data was impossible to do. It was also really hard to come up with a standard of production performance across the entire breed (working on that!). With that said, there is a strong relationship between racetrack performance and subsequent production, even with opportunity normalized for, so the racetrack performance values suffice.

If you take something as simplistic as Equinome's genetic test, Dawn Approach is a C:C variant in intron 1 of MSTN, his sire New Approach is a C:T variant and his sire Galileo is a T:T variant. With MSTN having an influence on muscle fiber type proportions (as per Petersen, et al), Dawn Approach is a completely different horse to Galileo in terms of muscle physiology.  This is where I think that genetics (recombination), regression of statistical data and heritability studies agree in thoroughbreds. The third generation and beyond of a foal in terms of real influence on outcome is just a name on a page. 5 years ago when we developed TrueNicks any combination beyond the 3rd generation on the sire's side and the 4th on the dam's side (so the grandsire of the sire and dam), recessed to the norm making their calculation meaningless.

Breeders hold onto "observations", "suspicions" and "theories" like passages from the King James Bible. No better one in recent memory than the well constructed fable of the X-Factor - take a long passed ancestor, attribute mystical powers to her and weave a story for all to believe. That was something straight out of the Da Vinci code..."the lost sacred feminine".

I do however take on board your latter comment about scrutinizing the statistical studies though. Many don't consider opportunity or variables that influence outcomes.

Byron Rogers 11 Jun 2013 5:14 PM

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