Flemington on Thursday turns its attention to the fillies, and a $1 million question that trainers, breeders and punters have spent the spring quietly turning over in their minds: which of these three-year-olds can truly run out 2,500 metres?

It is a distance that asks something most of the Crown Oaks field have never been asked to give. Form lines collapse at the furlong pole; sprint pedigree begins to feel its weight; and the filly who settles into a rhythm while her rivals shorten stride is, more often than not, the one who walks back into the mounting yard to the biggest cheer of her life.

This year's edition carries an unusually pointed subplot. Quick Finish, trained by Tony and Calvin McEvoy, backs up seven days after finishing third in the Howden Victoria Derby, making her the first filly in 36 years to have tested the 2,500 metres already.

It is a fact that will not be lost on her rivals' connections.

Bred by Yulong Investments, Quick Finish was offered at the Premier Sale but came home unsold when bidding stalled short of a modest $25,000 reserve. By Yulong's foundation stallion Grunt, a son of the celebrated staying influence O'Reilly, and out of an unraced Golden Horn mare, she traces on her dam's side to Listed winner Universal Order, a horse who got the full mile-and-a-half.

For a race decided on stamina, that is a detail worth underlining.

The favourite and her sister

Heading the market is Proxima Dea, the David Payne-trained winner of the Group 1 Spring Champion Stakes, and her bloodlines read like an argument for the distance rather than against it.

By Tarzino, who has already given the Australian Turf Club Derby winners in Jungle Magnate and Willydoit, she is a full sister to Gypsy Goddess, a Group 1 Oaks winner at 2,200 metres in Queensland. Their dam, the Redoute's Choice mare Invisible Coin, is herself a sister to Flight Stakes winner Cheeky Choice, and the pedigree page also carries Group 1 Rosehill Guineas winner Zabrasive and New Zealand Oaks placegetter Danasia.

In a race where the last 400 metres sorts the brave from the merely talented, a filly bred to stay on both sides of her pedigree begins with a head start the market has correctly recognised.

Maurice's trio

Arrowfield's Japanese shuttler Maurice has three runners in the race, and each tells a slightly different story about how a modern stallion reaches an Oaks.

Icelady, trained by Ciaron Maher, was a $130,000 Inglis Premier purchase and is a half-sister to dual Group 1 winner Kenedna, who won out to 2,200 metres and was fourth in a Queensland Oaks. Out of a Snitzel mare not short of Black Type, she is the best-credentialed of the Maurice trio on race performances, with four placings from seven starts including a placing at 2,000 metres.

Your Colour, from the Chris Waller yard, is the first foal from a Pierro mare who never won beyond 1,300 metres, but her second dam is the classy Danehill mare Your Colour, who took the Group 2 Emancipation Stakes at a mile.

Notified, trained by Archie Alexander, descends from Bonanova, the mighty miler who won the Group 1 Champions Mile at the turn of the century, and her page carries both the Listed Geelong Classic winner Extra Choice and Group 1 Spring Champion Stakes winner Fraternity.

The bargain hunters

For all the money in the staying pedigrees, the Oaks has always reserved a soft spot for the bargain buy, and this year's field is thick with them.

De Armas, the Group 2 Wakeful Stakes winner who now runs for Chris Waller, was a NZ$16,000 online purchase out of a New Zealand-based stallion whose page leans to speed rather than stamina but who arrives in winning form.

Voynichese cost Nick Olive just $30,000 out of Book 2 at the Magic Millions Gold Coast sale, yet her third dam is Zagalia, the Zabeel mare who won a Queensland Oaks when it was run at 2,400 metres. Her granddam Dawnie Perfect won the Group 3 Ethereal Stakes, one of the key Oaks lead-ups.

Salann, third in the Group 2 Moonee Valley Vase, was an $10,000 Inglis Classic buy by Shamus Award, sire of the quality stayers Incentivise and Duais. Her page traces back to Typhoon Tracy through a half-sister to her third dam.

These are the fillies who, on the first Tuesday in November, nobody wanted to buy. On the first Thursday, their connections will find out whether the market was right.

The staying question

For the rest of the field, the 2,500 metres is a step into the unknown.

Churchill Rose, trained in Adelaide by Andrew Gluyas, is out of a mare by Rebel Raider, a Group 1 winner at the Derby distance of 2,500 metres, and while there is little obvious distance form on her page, the pedigree leaves the door ajar. Expensive Taste, by North Pacific, traces back to a European family with form out to a mile-and-a-half. Nikitria, a $550,000 yearling by The Autumn Sun, is out of a Savabeel mare whose half-sister won the Group 1 New Zealand Oaks at 2,400 metres.

And then there is the waiting on Quick Finish, the filly who has already answered the one question every other runner is still being asked.

Whether she can back it up in seven days, against rivals who have been saved specifically for the race, is the final piece of a puzzle that has taken breeders, trainers and owners a full season to build. On Thursday afternoon, in front of the Flemington grandstand, the answer will come in the length of the straight.