Shotacross The Bow is tipped to make a mockery of his Queensland Derby odds when he steps out at Doomben.

Trainer David Murphy is excited about Shotacross The Bow stepping up to 2000m for the first time in the Group Three Rough Habit Plate on Saturday.

Shotacross The Bow has long been rated one of several Brisbane hopefuls for the Queensland Derby on June 11.

However, there is a diverse opinion among bookmakers on Shotacross The Bow's hopes of winning the blue-riband race with quotes varying from $81 to $26.

Murphy said $81 was generous for a horse which had always indicated the further he went the better he would go.

"We have had no luck with him his last couple. He got left in front when third in the Toowoomba Guineas and then he was a sitting shot again when fourth in the Gunsynd Stakes last time," Murphy said.

"I will be interested to see what price they have him for the Derby after Saturday's run.

"A few people might get a surprise."

Murphy has taken blinkers off Shotacross The Bow in an effort to help him settle.

Brad Pengelly will have the ride on Shotacross The Bow and Murphy is confident the experienced rider has the three-year-old worked out.

"Shotacross the Bow can be hard to ride but Brad has had a ride on him now and knows what to expect," Murphy said.

Meanwhile, co-trainer Paul Snowden is hoping or better luck with his filly Tap This in the Rough Habit Plate.

Tap This finished ninth in the Gunsynd Classic at her last start but should have finished much closer after getting held up in the straight.

"She doesn't like to go between horses and we will be trying to get her to the outside on Saturday," Snowden said.