Opie Bosson had the benefit of four-time Cox Plate-winning rider Brent Thomson's expertise at Moonee Valley ahead of perhaps the most important ride of his career on equal favourite Princess Coup in Saturday's $3 million Cox Plate.Bosson, 28, a former champion apprentice with more than 1,000 wins behind him including around 20 at Group One level, hasn't ridden in Melbourne for nearly a decade.He rode the classy Graeme Rogerson-trained filly Grand Archway four times for wins in the 1998 Wakeful S

Opie Bosson had the benefit of four-time Cox Plate-winning rider Brent Thomson's expertise at Moonee Valley ahead of perhaps the most important ride of his career on equal favourite Princess Coup in Saturday's $3 million Cox Plate.

Bosson, 28, a former champion apprentice with more than 1,000 wins behind him including around 20 at Group One level, hasn't ridden in Melbourne for nearly a decade.

He rode the classy Graeme Rogerson-trained filly Grand Archway four times for wins in the 1998 Wakeful Stakes and VRC Oaks, both at Flemington.

His last ride in Melbourne was when Grand Archway was a beaten odds-on favourite in the 1999 St George Stakes at Caulfield.

Connections of Princess Coup were keen for Thomson to show Bosson around the tricky circuit.

Thomson said his advice to Bosson was to be one off the fence in the run to the winning post the first time.

"The most important part of the race will be just before the 900-metre bend. He'd want to be rolling into it from there," he said.

Thomson's Cox Plate wins were on Fury's Order (1975), Family Of Man (1977), So Called (1978) and Dulcify (1979).

Bosson said the purpose of the walk was not so much to learn about the Cox Plate.

"It was mainly just to have a good look at the track," he said.

Bosson has faith in his ability to do the job.

"If she's good enough I should be able to do it," he said.

But as far as tactics go it all depends how the mare, a notoriously slow beginner, jumps.

"She's always tardy away from the barrier and we'll get back," Bosson said.

"She has a good turn of foot but it (how far back she'll be) all comes down to how she jumps."

Bosson said the wide barrier, nine in the 12-horse field, would suit the four-time Group One winner.

"She can sometimes miss it terribly so we'll wait and see. It depends on what she does on the day," he said.

"There's not much we can do with her, we've tried everything."

Bosson said he had watched a lot of races at the Valley and a lot of Cox Plates over the years.

He said the Valley had "a lot of turns" and with its short straight was "a totally different track" to the more spacious Hastings course where Princess Coup made it back-to-back victories in the Group One Kelt Capital Stakes (2040m) at her latest appearance.

Bosson, who has won four races, three of them at Group One level, on Princess Coup was understandably unwilling to talk about the pending New Zealand Judicial Control Authority inquiry he faces regarding him allegedly providing a clean urine sample for fellow jockey Bruce Herd during random drug testing at the Te Rapa meeting on October 3.

A date for hearing the charges against Bosson and Herd is yet to be set.

If found guilty, Bosson would be facing a lengthy suspension or disqualification.

After the Cox Plate, Bosson will begin a three-week suspension for careless riding in the Lion Red Plate at Tauranga last Saturday. He was also fined $3,000.