Key points
- A pedigree nick is a sire and broodmare-sire pairing (the mare's father) whose offspring have done better than expected, though not every time.
- A nick can also describe a pairing that does not work.
- Nick ratings compare how often a pairing produces stakes winners with how often the same sire and broodmare sire produce them with other partners.
- Letter grades run from A++ to F, and services do not share one scale, so name the service when you quote a grade.
- A nick is a statistical pattern. Ability, conformation, training, soundness, and race conditions still decide results.
- For a bettor, a nick is one clue, most useful for lightly raced horses, and never a standalone reason to bet.
What is a pedigree nick?
A pedigree nick is a breeding pattern, usually a match between a sire and a broodmare sire, that has produced superior results more often than expected. It does not work every time. The broodmare sire is the father of the mare, so a nick looks at the top line of a horse's sire and the bottom line of its dam's sire.
A nick can describe a pairing that does not work too, and it can be more complex than one stallion paired with one broodmare sire. Sire-line pairings can count as well.
A few supporting terms help here. The sire is the father. The dam is the mother. The broodmare sire is the dam's father. A cross describes how two bloodlines matched to produce a good horse.
The Inglis sales guide uses phrasing like "Fastnet Rock over Stravinsky mares is a nick that works." That is the idea in a single line: one sire, one type of mare, repeated good results.
How a nick works: a worked example
The Inglis guide points to two real crosses. Danehill over a Mr Prospector mare produced Flying Spur. Fastnet Rock over a Zabeel mare produced Atlantic Jewel.
Lay out the first one as a simple pedigree. Danehill is the sire. The dam is the mare. Mr Prospector is the dam's sire, so he is the broodmare sire. The nick is the Danehill and Mr Prospector pairing, not the single horse.
One famous horse does not make a nick. The nick is the rate behind it. A rating service asks how often this pairing produces stakes winners, then asks how often that same sire and that same broodmare sire produce them with other partners. If the pairing does better than the two do elsewhere, it has a case.
TrueNicks explains that a rating of 2.0 means the cross produces stakes winners at twice the rate the same sire and broodmare sire achieve with other partners. A rate also needs enough starters behind it. A pairing with a handful of runners can look strong by luck.
How nicks are rated
Rating services turn that comparison into a grade. TrueNicks uses a letter scale from A++ down to F, along with a numeric variant. Its explanation draws on a Sire Improvement Index and a Broodmare Sire Improvement Index.
The numeric scale is not linear. Scores below opportunity run from 0.01 to 0.99, while scores above opportunity can reach 500 or more. That is why a number alone says little until you know where it sits.
TrueNicks published figures that show how rare a high grade is. In an article from 2010:
- 13% of all Thoroughbreds rate A or better, versus 37% of stakes winners.
- 30% of all Thoroughbreds rate B or better, versus 77% of stakes winners.
- 44% of the general population rates C to F, versus 8% of stakes winners.
Those figures come from one service and one date, so confirm they still hold before relying on them. Grades are not standardized across services. TrueNicks suggests B+ or better as a starting point. The same article advises looking at the quality of the top horses the cross has produced, not only the grade.
Nick vs. cross, inbreeding, and bloodline
Readers often mix these terms up.
A nick is a repeatable pattern between a sire and a broodmare sire. A cross is the single match of two lines that produced a horse. Inbreeding, including linebreeding, means the same ancestor appears more than once in one pedigree. A bloodline is a general line of descent and does not need a specific pairing.
For more terms in this group, see the glossary section on pedigree and breeding.
What a nick cannot tell you
A nick is a statistic, not a guarantee. It leaves out conformation, individual ability, training, soundness, and race conditions. A horse with an A++ cross can still be slow, sore, or poorly placed.
Not everyone accepts nicking. A Thoroughbred Review piece titled "Nicks: The Final Nail" describes nicking as having been sold to the public as "trumped up science." A Blood-Horse white paper on nick myths, published through TrueNicks, says nick ratings are not magic bullets. The two positions differ in tone, and both warn against over-weighting the number.
The research available for this entry does not include an independent study that tests whether nick ratings predict results beyond the quality of the sire and the broodmare sire. Treat the claim with care.
That fits how data should work for a bettor: it supports your judgment and does not promise winners.
Do pedigree nicks matter when handicapping a race?
Sometimes, in a limited way. Pedigree carries more weight when past performances are thin: a lightly raced horse, a first-time starter, or a horse moving to a new distance or surface. Once a horse has a solid record at the trip and surface, its past performance data should lead.
Treat a nick as one input beside pace, form, and class. It can support a read you already have, or make you question one. If a first-time starter looks short on form but carries a strong cross for the distance, that is a reason to look closer, not a reason to bet.
AI-powered handicapping folds pedigree into a wider picture. EquinEdge's Genetic Strength Rating (GSR®) uses pedigree to judge a horse's suitability for a race's distance and surface. The EE Win Percentage accounts for sire stats, dam stats, sire progeny stats, and dam progeny stats alongside other factors. EquinEdge does not calculate nick ratings. You can try the platform with a free trial.
To find pedigree and breeding codes on a race card, see this guide to past performance abbreviations.
FAQ
Where can I look up a horse's pedigree and nick rating?
Pedigree appears on most past performance pages and sale catalogues, and the broodmare sire is listed under the dam. Nick ratings come from rating services such as TrueNicks. Because grades differ by service, note which one you are reading.