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

Tara Madgwick - Friday August 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...
Zed 9YO Wins G3 Winter Cup
Saturday’s $110,000 Group Three Winning Edge Presentations Winter Cup (1600m) at Riccarton continued an incredible ride for the connections of Chase (NZ) (Zed), who bought him for only $9,000 from Book 3 of Karaka 2018. Originally a $6,000 purchase by JD Corcoran when offered as a weanling from Valachi Downs in the 2017 National Weanling, Broodmare & Mixed Bloodstock Sale.
Nominees Announced for Australian Racehorse of the Year Awards
The nominees for the prestigious 2024/2025 Australian Racehorse of the Year awards have been announced today by Racing Queensland in association with Racing Australia.
Victorian Breeders Celebrate Annual Awards Night
The 2025 Victorian Breeding Awards has once again showcased the outstanding achievements within Victoria’s thoroughbred breeding and racing industry.
G1 Plans for Wexford Stable Mares
Lance O’Sullivan and Andrew Scott have their sights set on the opening Group One of the season with a pair of talented mares, both of which appeared at the Taupo trials on Monday.
Per Incanto Mare Wins $100,000 Polytrack Championship
Synthetic flyer Cosentino silenced any doubt about running out the seven furlongs with a blistering performance to claim Sunday’s $100,000 Japac Homes Polytrack Championship (1400m) at Awapuni.
Blue Gum Farm Welcome First Foal of the Season
Victorian nursery Blue Gum Farm announced on Monday the arrival of their first foal of the season and there is no mistaking the sire of this gorgeous filly.
One to Watch – Ballarat
Last seen contesting the Group I MRC Blue Diamond Stakes, newly gelded three year-old Olatunde bolted in at Ballarat on Monday continuing the fast start to the new season for his sire Farnan.
Too Darn Hot Mare Claims Third G1
Too Darn Hot (GB) will be a returning superstar to Darley NSW this spring and there is no doubt he can get an exceptional horse with Fallen Angel capturing her third Group I in France on Sunday when taking out the G1 Prix Rothschild (1m) at Deauville.
Aussie Globetrotting Mare Now Calls Woodside Home
Woodside Park have released a list of their quality mares set to visit new recruit Celestial Legend this spring and one of them is Aussie bred Group II winner Nafaayes, who produced a promising 2YO winner overnight in the UK.
MM Yearling Sales 2026 Open for Entry
The 2026 Magic Millions Yearling Sales - from the Gold Coast in January to Perth and Tasmania in February and the Gold Coast and Adelaide in March - are ready to deliver more groundbreaking results.