Mine and Refine – How to Build a Champion Sireline in 30 Years

Tara Madgwick - Friday Aug 30

When you go to the Hunter Valley on a trip looking at stallions you see a lot of them and sometimes (although you don’t know it at the time) you may well see a horse that will change the course of breeding history as the waxing and waning of sirelines over time is rarely straight forward and frequently delivers the unexpected.

How does a dirt track speed sire line built on juvenile speed evolve to deliver the best classic three year-old in Europe on turf up to 2400m?

If you’ve been going to the stallion parades for the past 30 years you will have seen quite a few pieces in this fascinating puzzle.

Stallion

Best Wins

Lifetime SW to runner

Storm Cat 1983

G1 Young America Stakes (at 2)

18.5%

Hennessy 1993

G1 Hopeful Stakes (at 2)

6.4%

Johannesburg 1999

G1 Breeders Cup 2YO, Middle Park Stakes, Phoenix Stakes, Prix Morny (all at 2)

4.4%

Scat Daddy 2004

G1 Champagne Stakes (at 2), G1 Florida Derby (at 3)

13.4%

Justify 2015

G1 Kentucky Derby, Preakness Stakes, Belmont Stakes (at 3)

9.6%

City of Troy 2021

G1 Epsom Derby, Coral Eclipse, Juddmonte International (at 3)

G1 Dewhurst (at 2)

To come

The most exciting racehorse in the world right now is three year-old Justify colt City of Troy, who was last year’s Champion European 2YO and is well on his way to being this year’s Champion European 3YO and possibly Horse of the Year with a string of recent wins in the Group I Epsom Derby, Coral Eclipse Stakes and Juddmonte International in course record time.

City of Troy wins the G1 Juddmonte International - image Coolmore

A homebred for the Coolmore partners he is the result of a sireline they have mined and refined over the past 30 years going back to Hennessy (USA), who first shuttled to Coolmore Australia in 1997.

Hennessy (USA) shuttled to Coolmore Australia for five seasons.

A speedy Group I winning juvenile with a lengthy, muscular sprinter’s physique, Hennessy was by the legendary breed shaping US sire Storm Cat, who produced a champion for Coolmore in Giant’s Causeway. European Horse of the Year in 2000, Giant’s Causeway went on to become a champion sire in North America for Coolmore and shuttled to Australia for three seasons, but it is Hennessy that has spawned the sireline to deliver their current superstar City of Troy.

Advertisement

Hennessy sired 72 stakes-winners worldwide with the best of his offspring being Australian bred seven time Group I winner Grand Armee, while his best in the Northern Hemisphere was World Champion 2YO Johannesburg, who won four Group I races at two in four different countries on turf and on dirt.

Hennessy shuttled to Australia for five seasons between 1997 and 2001 and was then followed by Johannesburg, who also came for five seasons from 2002 to 2007.

Johannesburg (USA) shuttled to Coolmore Australia for five seasons.

Johannesburg was not as good a sire as Hennessy, who was nowhere near as good a sire as Storm Cat, so you can understand why Australian breeders said no thanks to Scat Daddy when he was mooted as a potential visitor and he was sent to South America instead.

Scat Daddy shuttled to South America, where he became a champion sire.

Scat Daddy died prematurely at age 11 when he was just starting to get the serious recognition he deserved and in his penultimate crop produced Justify, an unbeaten Triple Crown winner, that was raced by China Horse Club and partners and purchased by Coolmore on retirement.

Justify (USA) has shuttled to Australia for four seasons.

Justify has also come to Australia for Coolmore and his top class colt Storm Boy is resuming in the Group III ATC San Domenico Stakes on Saturday.

Advertisment
More Reading...
Remembering Northerly – The Greatest Caulfield Cup Winner This Century
It's Caulfield Cup week, and what better moment to revisit the life and times of one of the greatest - if not the greatest - Caulfield Cup winner of the modern era.
Gundagai Maiden Winners Collect $72,000!
For many racehorses the only race they will ever win is their maiden and Inglis have spread the money into this very important area with their Xtra Bonus Series and two $50,000 bonuses went off at the always popular Snake Gully Cup meeting at Gundagai on Friday to the great delight of connections of Essay and Southern Grace.
Breeding To Win - G1 CF Orr Stakes
The last Autumn running of the CF Orr Stakes in 2025 closed a long chapter when Another Wil narrowly denied Mr Brightside consecutive victories and the historic first running of the “new” race in November last year had a worthy winner in race favourite Jimmysstar, who is back to defend his title.
Sires With Winners - Friday November 13
Here is the full list of 65 stallions which had winners throughout Australasia today with winners and result details.
Remembering Sunline – The Queen of the Cox Plate Before Winx
From our vantage point in 2026, we can look back at modern Cox Plate history and marvel at how quickly the years are passing.
Group One performer Myakkabelle goes under the hammer on Gavelhouse Plus
Gavelhouse Plus is giving breeders the chance to add a Group One performer to their broodmare band with the auction of multiple black-type placegetter Myakkabelle.
Sires With Winners - Thursday November 12
Here is the full list of 46 stallions which had winners throughout Australasia today with winners and result details.
G1 CF Orr Stakes - An Old Race in a New Time Slot
Four days of Flemington action are behind us for another year, and what a grand feast of horse racing it was - now Melbourne’s carnival continues with the second running of the MRC's time-honoured G1 CF Orr Stakes, in its new place on the racing calendar.
Expensive Ready to Run Graduate Primed for G1 NZ 2000 Guineas
There is plenty of hype surrounding promising gelding Thunder In Motion ahead of Saturday’s Gr.1 Al Basti Equiworld Dubai New Zealand 2000 Guineas (1600m) at Riccarton, and trainer Mark Forbes is hoping he can deliver in the southern Classic.
ATO Takes Harder Line on Losses
For such a contentious topic—particularly for participants in the thoroughbred industry—the wait for updated ATO guidance on whether an activity is a “business” or a “hobby” has certainly been a long one.