But try telling that to local trainers Peter and Will Hulbert, who hope to again prove a giant killer with Criminal Defence in the 2400-metre feature.
Criminal Defence was a $71 boilover winner of the Group 3 Rough Habit Plate over 2000 metres at Doomben a fortnight ago, but the upset win never surprised Team Hulbert.
In early Derby markets, Explosive Jack is a dominant $2.90 favourite while Criminal Defence is at $21 following his Rough Habit victory.
"It wasn't a fluke he won the Rough Habit and it was only his barrier that frightened me," said co-trainer Peter Hulbert.
Hulbert has been training for more than 40 years and the Rough Habit triumph was easily his greatest win.
Hulbert attributed much of the win to champion jockey Michael Rodd, who will miss the Eagle Farm meeting with an ear infection.
"Michael came down and rode him one morning and suggested we take the blinkers off him for the Rough Habit and it was the first time he jumped properly," he said.
"He's going to 2400 metres this time which is a query but his breeder rang me during the week to say he's got the great Secretariat bloodlines on his dam's side so he shouldn't have a problem getting the trip.
"When he won the Rough Habit, it was a slow tempo in front and he was allowed to get into a good position from his wide draw.
"But he's drawn a lot better this time which brings him right into the race and takes out any bad luck from the start."
Rodd has been replaced by Victorian jockey Jye McNeil, who got the surprise call up from Hulbert's son Will on Tuesday morning.
Victorian Explosive Jack is trained by Ciaron Maher and David Eustace and etched his name into the history books when he became the first horse in 44 years to win three Derbies in a season.
He won the Listed Tasmanian Derby in Hobart in February, then claimed the Group 1 Australian Derby at Randwick in April before adding the Group 1 South Australian Derby at Morphettville to his resume on May 8.
Stormy Rex completed a similar feat claiming a Derby hat-trick in Victoria, South Australia and Western Australia in 1977.
If successful, Explosive Jack will match the deeds of the Bart Cummings-trained superstar Dayana who claimed four Derby victories in 1972.
Explosive Jack will be joined in the Queensland Derby by stablemate Let's Karaka Deel who was beaten just over two lengths when second to Explosive Jack in the South Australian Derby.