The David Hayes stable discovered the key to Whisper Downs about four runs into his current preparation and have kept turning it for the past six months.

Whisper Downs, who is a contender for the title of the most durable horse in training, has been in work since last July and proved at Caulfield on Saturday that a few more runs are well within his capabilities.

"We worked out early in his prep that he was being ridden the wrong way," said Hayes' foreman Bruno Rouge-Serret.

"And we were probably running in races that were too short."

Whisper Downs, favourite at $3.50 favourite, took his earnings for his current preparation beyond $300,000 with his win in the Smart Track Australia Handicap (2000m) and the stable will now give consideration to stepping him up to something better.

The son of the Hayes-trained stakes winner Churchill Downs came from near the tail of the field to beat stablemate Auld Burns ($6) by three-quarters of a length with Second King ($6) a distant third.

For winning jockey Chad Schofield the win was his fifth on the horse, but if he'd had his own way he'd have missed out on the past three.

"Chad wanted to send him for a spell five or six runs back," said Rouge-Serret. "But David knew best."

Whisper Downs is likely to go to Sydney for a minor race during the autumn carnival.