When Pedigree Maths Meets the Winner's Circle: Decoding the May 2-3 Graded Stakes Card

The first weekend of May 2026 delivered 27 graded stakes races across nine jurisdictions. Kentucky Derby weekend headlined the card. Newmarket ran the 2000 and 1000 Guineas. Eagle Farm fired up its Queensland winter carnival. Greyville and Kenilworth carried the South African flag. And quietly, in the data behind every starter, a familiar pattern emerged.

The horses that won had pedigrees that already looked like winners.

The headline number

Across the 25 graded flat stakes winners we tracked over the weekend, 23 of them (92%) carried either a Perfect Match or 20/20 Match rating in Stallion Match. Only two winners were rated No Match.

That breakdown:

• Perfect Match: 5 winners (20%)
• 20/20 Match: 18 winners (72%)
• No Match: 2 winners (8%)

In other words, more than nine in ten elite winners on the card had pedigree compatibility signals strong enough to flag in advance.

A note on scope. Two graded hurdle races at Punchestown have been excluded from this analysis. Stallion Match and Impact Profile are built on flat-racing data, and applying them to jumps stock produces ratings that aren't meaningful. The numbers above are flat-only.

The grade-by-grade view

The relationship gets sharper when split by race grade.

Every G3 winner on the weekend, all eight, carried at least a 20/20 Match rating. The only unrated horses were both at the top end of the card: a USA G1 (R Disaster, Derby City Distaff) and a USA G2 (Classic Q, Distaff Turf Mile). We'll come back to those.

What Stallion Match and Impact Profile actually measure

For members new to the platform, the two ratings answer different questions, and both are grounded in real stakes-winner data rather than theoretical compatibility scores.

Stallion Match asks a direct question: how closely does this proposed pedigree resemble pedigrees that have already produced stakes winners?

• A 20/20 Match means the proposed pedigree is at least 65% similar to multiple existing stakes winners' pedigrees, and the count of matching stakes winners clears a minimum threshold. The pedigree pattern, in other words, is one that has demonstrably worked before, more than once.
• A Perfect Match is a 20/20 Match that goes further. The matching stakes winners share ancestors with the proposed mating across all four pedigree quarters: the sire's sire side, the sire's dam side, the dam's sire side, and the dam's dam side. The pedigree similarity isn't running on one or two sides of the family. It's running on all four.

Put another way, a 20/20 Match says "this pedigree shape has already produced multiple stakes winners." A Perfect Match says, "this pedigree shape has already produced multiple stakes winners, and the matching ancestors run through every quarter of the family."

Impact Profile is a different lens. It is an expectation algorithm that analyses 20 ancestor crosses across four generations of a horse's pedigree, using both male and female ancestors. (Many other industry tools only consider male ancestors, which is one reason Impact Profile gives a fuller picture.) For each cross, the algorithm calculates how the cross has actually performed compared to the expected rate, and assigns a score:

• Gold highlight: a very high positive score. The cross has performed exceptionally relative to expectations.
• Green highlight: a positive score. The cross has outperformed expectations.
• Red highlight: a negative score. The cross has underperformed expectations.
• X: not enough data to compute a meaningful score for that cross.

(The platform also offers an Impact Analysis - Tight view, which sharpens the same analysis by considering each ancestor's exact position within the pedigree, e.g. maternal grandsire versus paternal great-grandsire. It produces more precise reads where the data exists, and more 'X' cells where the sample sizes are too small.)

The two ratings are complementary. Stallion Match scores how the whole pedigree compares to known stakes-winner shapes. Impact Profile scores how each individual ancestor cross has actually performed against expectation. When both line up, you have two independent data points pointing the same direction.

Perfect Match horses had nearly twice the Impact breadth of 20/20 horses

Cross-tabulating the 21 weekend flat winners, we have full Impact Profile data on against their Stallion Match rating produces this:

This is what you'd expect to see if the two ratings are measuring something real. Perfect Match horses, where the pedigree similarity runs through all four quarters of the family, also tend to have the broadest Impact support across their individual ancestor crosses. More than half of their Impact Profile matrix lit up positive on average. The 20/20 Match group, where the pedigree similarity is real but doesn't necessarily run through every quarter, averaged about half that breadth.

The No Match group is small (n=2), and the average is dragged up by Classic Q, who has interesting Impact depth even though her specific cross didn't clear the Stallion Match threshold. We'll come to that case.

These are small samples on the weekend, but the directional signal aligns with our broader validation work. In our Magic Millions cohort study (n=2,502 lots), Perfect Match horses became Stakes Winners at 7.4% versus 3.9% for 20/20 Match and No Match, and Group Winners at 7.4% versus 2.3% and 2.1%. Perfect Match horses across that benchmark were roughly 2x more likely to be Stakes Winners and 3.5x more likely to be Group Winners.

The standouts — Perfect Match horses with deep Impact Profiles

These are the four horses on the weekend card who carried Perfect Match plus measurable Impact strength:

Golden Tempo, Kentucky Derby (G1, USA)

Curlin x Carrumba (by Bernardini). Perfect Match. Four gold cells, ten green cells in Impact Analysis. Fourteen of the twenty crosses outperformed expectation, with four of those classed as exceptional. The Curlin x Bernardini cross at the close pedigree position is the headline signal. Beat 17 rivals on the first Saturday in May.

Bow Echo, 2000 Guineas (G1, GBR)

Night Of Thunder x Aristocratic Lady (by Invincible Spirit). Perfect Match. Two gold cells, thirteen green cells. Fifteen of the twenty crosses positive, the broadest profile of any winner on the weekend. The depth across the broodmare-sire side is the standout: every dam position outperformed expectation against the sire line.

Beatty, WA Sires' Produce Stakes (G3, AUS)

Gingerbread Man x Femmette (by Murtajill). Perfect Match. Five gold cells. A young sire (Gingerbread Man) crossing with a relatively unproven broodmare-sire line, but the data flagged the cross as one to back. Caveat: some of Beatty's gold cells are based on small samples, which can amplify the score. The Perfect Match rating, which depends on pedigree similarity to multiple stakes winners across all four quarters, is the more durable signal here.

World's End, Keio Hai Spring Cup (G2, JPN)

Lord Kanaloa x Lilavati. Perfect Match. Seven crosses outperforming expectations across the Impact Profile matrix. A clean Japanese-line cross where the Sunday Silence and Storm Cat threads upstream interact with the Lord Kanaloa speed in the right balance.

(Star Major, the fifth Perfect Match horse, won the WSB Guineas at Greyville for South Africa. We didn't capture full Impact Profile data for this horse in our weekend run, but the Perfect Match rating is on the platform.)

The 20/20 Match winners worth flagging

Within the 20/20 Match group, several horses carried gold-cell counts that would have made the Perfect Match tier in many of the close metrics.

• Stark Contrast (G1 American Turf): four gold, three green. Caravaggio x Catch The Eye, with the Scat Daddy x Quality Road thread doing real work.

• Skyhook (G3 Hawkesbury Guineas): three gold, five green. Written Tycoon x Madame Pauline. The Redoute's Choice x Written Tycoon cross at the close position has produced 37 stakes winners against expectation, classed as exceptional. (Disclosure: I'm a part-owner of Skyhook, so I'm biased, but the numbers don't change.)
• Mondego (G2 Charles Whittingham): two gold, eight green. Lope De Vega x Free Rein, with depth through the Shamardal and Danehill lines.
• Crude Velocity (G2 Pat Day Mile): two gold cells anchored by a strong Liam's Map x Beau Liam cross.
• Deterministic (G3 Fort Marcy): two gold, nine green. Eleven of the twenty cells were positive on the Impact Profile matrix.

The exceptions — and what they tell us

Two flat winners on the weekend rated No Match: R Disaster (G1 Derby City Distaff) and Classic Q (G2 Churchill Distaff Turf Mile). Both are interesting cases.

R Disaster is the cleaner exception. A genuine G1 winner whose pedigree didn't clear the 65% similarity threshold against the existing stakes-winner population, and showed no positive Impact signal on the cross we model. That's the kind of result that keeps any breeding model honest. Pedigree is necessary but not sufficient. Training, fitness, racing luck, and unmodelled variables matter, and they always will. A model that explained 100% of outcomes wouldn't be a model, it would be a fairy tale.

Classic Q is the more nuanced case. Despite the No Match Stallion Match rating, the Impact Profile actually shows five gold cells and one green cell on the wider pedigree. This is the case where the whole-pedigree similarity didn't reach the threshold, but individual ancestor crosses in the family have outperformed expectations. The No Match rating reflects the whole-pedigree comparison. The Impact gold cells reflect that her ancestor crosses have produced elite horses through other matings. Both can be true. Worth a deeper dig in a future article on when the two ratings disagree.

Why this matters for breeders and buyers

Pedigree matching isn't a guarantee. It's a probability shifter. The question to ask is whether the shift is large enough to change what you do.

Three pieces of supporting work suggest it is.

One, the Magic Millions cohort. Across 2,502 lots, Perfect Match horses produced Group Winners at 3.5x the rate of unrated lots.

Two, the Dam Quality work. Across 552,130 horses, we found a clean stakes-winner-rate hierarchy by dam class: G1-winning dams at 9.98%, G2 at 8.36%, G3 at 8.06%, Listed at 6.94%, non-stakes-winning dams at 3.62%, never-won at 3.17%. A G1-winning dam triples the baseline rate. A non-stakes-winning dam barely beats it.

Three, the female family compounding. When a horse has three or more stakes-winning siblings, the SW rate climbs to 15.69%, nearly five times baseline. Pedigree depth on the dam side compounds. It doesn't replace the sire decision, but it sharpens it.

Combine all three, and you have a framework. Pick a stallion. Pair him with a dam at the highest pedigree tier you can afford. Cross-check the specific match in Stallion Match to see how closely the proposed pedigree resembles existing stakes winners. Look at the Impact Profile to see whether each individual ancestor cross has outperformed expectations. The weekend's results are not proof that this framework works in every case. They're a reminder that, in aggregate, it consistently lines up with the sharp end of the form sheet.

What we'll do with this data

The full breakdown of all 25 weekend flat winners, their Stallion Match ratings, and their full Impact Profile cells is available to G1 Goldmine Pro members on the platform. The cross-tab analysis above is a snapshot. The members' platform shows you the same view for any horse, any matching, any sale.

If you're a Plus member (G1 Goldmine Standard user) who wants to see the Impact Analysis - Tight view (which considers each ancestor's exact position within the pedigree), upgrade to Pro. If you're a free member who wants to start checking your own targets, the Stallion Match rating is the place to begin.

We'll be back next week with the same analysis on whatever the form sheet throws up. The data, as always, gets there before the results do.

Matthew Ennis is the founder of G1 Racesoft, the company behind G1 Goldmine and Stallion Match. He is also a part-owner of Skyhook through Stallion Match.

All data sourced from the G1 Goldmine database. Impact Profile uses 5x4 matrix mode with Show 3rd Sire enabled. Stallion Match ratings as of May 2026. This analysis covers flat graded stakes only; jumps races are excluded as the underlying data models are built on flat-racing performance. For a full explainer of how Impact Profile works, see the Help Centre article "Horse Information - Why the Pro's use it!"