Already one of Australia's most successful jockeys, Steven King heads to Rosehill on Saturday on the threshold of greatness.If Rostova wins the Golden Slipper, and King is confident she can, the 39-year-old will join an elite group of riders to claim racing's grand slam.Only six others - Neville Sellwood, Roy Higgins, Pat Hyland, Mick Dittman, Jim Cassidy and Damien Oliver - have won the Melbourne Cup, Caulfield Cup, Cox Plate and Golden Slipper.King won the Caulfield-Melbourne Cup double on Let

Already one of Australia's most successful jockeys, Steven King heads to Rosehill on Saturday on the threshold of greatness.

If Rostova wins the Golden Slipper, and King is confident she can, the 39-year-old will join an elite group of riders to claim racing's grand slam.

Only six others - Neville Sellwood, Roy Higgins, Pat Hyland, Mick Dittman, Jim Cassidy and Damien Oliver - have won the Melbourne Cup, Caulfield Cup, Cox Plate and Golden Slipper.

King won the Caulfield-Melbourne Cup double on Let's Elope in 1991 and the 2003 Cox Plate on Fields of Omagh and would like nothing more than to complete the set.

"It's something every jockey wants to do and few have," King said.

"It is certainly something I have always wanted to do and Rostova is my best chance in the Slipper for sure.

"Hurricane Sky came off his Blue Diamond win and was coming to the end of his preparation.

"This filly is still on the way up."

Hurricane Sky ran fifth to Danzero in 1994 after winning the Blue Diamond while the only blot on Rostova's record was the Blue Diamond.

King and trainer Steve Richards believe she choked down after getting her tongue over the bit and a gear adjustment was made.

The filly came out at her next start wearing a tongue tie and duly won the Group Two VRC Sires' Produce Stakes.

Rostova was not among the original nominations for the Slipper but her Sires' Produce win convinced her owners to pay the $150,000 late entry fee.

Since being confirmed as a starter, Rostova has been steady on the third line of betting with most agencies behind Real Saga and More Joyous.

A couple of years ago, King spent five months on the sidelines with a broken leg but said he never considered turning to another profession.

"It was the first decent break of my career," he said.

"I didn't think of giving it up but I did reassess things and now I target the horse I want to ride and one that will take me through.

"Unless you are riding for a big stable things like premierships are not going to happen so finding the right horse is what I have to do.

"I was riding Littorio last spring and Rostova was next door to him at Flemington so I got to know her well.

"She is a temperamental filly but I knew she was something very special early on."

Rostova won her first three starts before faltering in the Blue Diamond and has maintained her condition and fitness.

"Her first wins were soft wins, all very soft," King said.

"The Blue Diamond she only went for half a mile (800m) and then she choked down so she really didn't have a hard run."

In keeping with his policy of finding the right horse and sticking to it, King has given up rides in Melbourne over the past couple of weeks to help Rostova settle in to life in Sydney.

She ran second to Slipper rival Reward For Effort in a barrier trial last Friday and has adapted to the right-handed way of racing well.

"She needed the experience going the Sydney way and I was happy with how she handled it and how she has done since," King said.

"She seems focused."

As is her jockey.