Royal Descent's long last in the Caulfield Cup might not look like much of a form guide but her trainer Chris Waller can draw many positives.

The mare will run in Saturday's Myer Classic over 1600m, a distance her record says is her best despite her 2013 Australian Oaks win over 2400m, the same distance as the Caulfield Cup.

"Glen Boss shut her down when it was obvious she couldn't win the Caulfield Cup and didn't punish her," Waller said.

"She worked hard early to get across from the outside barrier and Bossy didn't punish her late.

"She came out of the race just a few kilos lighter and we haven't done much with her since.

"A mile is her best distance and her record in Doncasters, Epsoms and George Mains is there to see."

Royal Descent has run a place in two Doncasters and an Epsom and has been runner-up in the past three George Main Stakes.

Her spring preparation began with an overdue victory in the Group Two Warwick Stakes, her first win since the Oaks.

"She won the Oaks by ten lengths on a very wet track but that is misleading because when they are three against their own sex, that doesn't always translate as they get older," Waller said.

"She came into this spring heavier than she has ever been and has pretty much maintained that all the way through."

Bookmakers agree with Waller the mare can bounce back and she is the $5 second favourite for the Myer behind the David Hayes and Tom Dabernig-trained Stay With Me at $3.80.

Hugh Bowman, who rode the Waller-trained Winx to win Saturday's Cox Plate, will be back on Royal Descent who wore blinkers in an easy work-out at Flemington on Tuesday.

Stablemate Amicus is a $21 chance in the Myer with Blake Shinn to ride.