On for young and old – How the formula for a Slipper winner has changed

On Saturday night, there is a chance that the folks at Arrowfield Stud will be toasting a fourth Golden Slipper winner for the late, legendary stallion Snitzel.

He may have had to settle for 12th place in the race himself, but Snitzel has been the most successful Slipper sire since his famous grandsire Danehill’s progeny won five editions of the race between 1994 and 2001.

Across his 26 individual runners in the race, Snitzel has had three winners, Estijaab, Shinzo and Marhoona, and four placegetters. He has also had a winner as a damsire (Mossfun).

On Saturday, the first Slipper since his death last year, Snitzel is represented by Fireball and Campione D’italia, both around the $16 mark. A win would also represent a third for the Arrowfield champion in the race in the past four editions and stamp a clear path to a fifth Australian sires’ championship.

He is one of four sires with representatives in the race who were themselves foaled more than 20 years ago. The others are Magnus (2002), who has Streisand, I Am Invincible (2004), who is represented by the favourite Chayan, and Street Boss (2004), who has Closer To Free.

A victory for any of those five horses would be the fourth year straight that the winner has come from a stallion who was aged, or would have been aged, 20 or over.

That would seem a random, irrelevant stat, apart from the fact that it hadn’t happened for 36 editions of the Golden Slipper before 2023.

You have to go back to 1986, when Biscay’s Bounding Away won the race, to find a sire over the age of 20 when the race was run.

The average age of a Golden Slipper-winning sire since 1983 has been 12.95, yet the recent trend has blown out towards the older side, with an average of 16.7 in the 2020s.  Only three of the past 19 editions have been won by the progeny of a sire who was under 10.

There is a similar trend when it comes to the average age of Golden Slipper-producing mares when the race is won. The average in the 2020s is 12, while the average since 1983 has been 10.9.

The combined age of 37 of last year’s winner Marhoona’s sire and dam was the oldest of any Slipper winner in records we checked back to 1983. Snitzel was 22 and Salma was 15.

There have only been three instances since 1990 where the combined age of sire and dam of the Golden Slipper was over 30 and all three of those were in the past three years.

Marhoona was her dam’s eighth foal and Salma was the oldest Golden Slipper producing broodmare since Vancouver’s dam Skates, who was 18 in 2015.

The 2024 winner Lady of Camelot was Miss Debutante’s, third foal. She was a comparatively sprightly 10-year-old when her Written Tycoon filly won the Slipper.

The last first foal to win the race was Fireburn, whose dam Mull Over was eight at the time. She is the youngest mare to be a Golden Slipper producer since Eye For Fun, Mossfun’s dam who was just four when she foaled her and six when she won in 2014.

So how do we apply that to this year’s race?

There are five horses on Saturday who, when you add the current (or projected) age of their sires and dams, come to more than 30. All five of those horses are named above as the ones with sires over 20.

The youngest sires with runners in the race are Home Affairs, Sword Of State (a son of Snitzel) and Stay Inside, all of whom are seven. There are three horses whose dams are only eight, Warwoven, Paradoxium and Incognito, while there are another four whose dams are only nine.

Historically, just one of the past nine Slipper winners had a dam under 10, while just one of the past 17 has had a combined sire-dam age of less than 20.

Warwoven and Incognito have a combined sire-dam age of just 15. If either were to win, they would become the first to emerge from such a young combination of sire and dam since Miss Finland (also 15).

Golden Slipper field and current ages of sires and dams

(Projected age in instance were sire and dam is no longer living)

Horse	Sire age	Dam age	Combined
Fireball	23	9	32
Closer To Free	21	9	30
Guest House	7	13	20
Warwoven	7	8	15
Paradoxium	12	8	20
Stretan Ruler	8	12	20
Zambales	8	12	20
Music Time	16	11	27
Campione D’italia	23	13	36
Hidrix	12	9	21
Incognito	7	8	15
Streisand	23	10	33
Spicy Miss	11	9	20
Chayan	21	12	33
Shiki	9	12	21
Pembrey	8	15	23

Source: Australian Studbook