James McDonald concedes he will be doing well to continue a winning streak in Sydney's Group One weight-for-age races despite riding one of the favourites in the $1.5 million BMW.

McDonald will ride Hartnell for Godolphin but admits he is in awe of the form line belonging to the Japanese star To The World.

And even allowing for his mount's impressive Sky High Stakes win and the presence of last year's Melbourne Cup winner Protectionist, McDonald says To The World might be classes above his BMW rivals.

"They reckon (To The World) is one out of the box which if you go through his form it looks like that," McDonald said.

"If he turns up and brings probably eighty per cent of his A game he will probably win the race."

McDonald has won every Group One weight-for-age run so far during the Sydney autumn carnival, landing the Chipping Norton Stakes, Canterbury Stakes, Ranvet Stakes and George Ryder Stakes.

He won the George Ryder on To The World's travelling partner Real Impact, ensuring he speaks from a position of authority when it comes to the Japanese horses.

His analysis will bring little comfort to bookmakers who have been hit hard since BMW betting was reopened after Wednesday's barrier draw.

To The World replaced Hartnell as favourite on Thursday and the four-year-old has moved closer to starting odds-on with further support on Friday.

Hartnell has eased to $3.50 and is rated the only serious threat to To The World although Protectionist ($7) continues to be backed.

Trainer John O'Shea is hoping Hartnell sprints as well as fellow Godolphin import Contributer did in winning the Ranvet last week.

"We had to ride him a certain way (in the Sky High) to get the job done but I think he will be better ridden a bit quieter," O'Shea said.

"He is as well as we can have him and now we're just hoping he is good enough."

Golden Slipper-winning jockey Tommy Berry rides the only three-year-old in the race when he partners the $51 outsider Hampton Court.

Berry has joined McDonald in claiming To The World is the horse to beat, citing Admire Rakti's Caulfield Cup win as further proof of Japan's strength in long-distance races.

"When it comes to a staying trip they've definitely got an edge on the Australian horses," Berry said.

"They come out and prove themselves and I think you will see the best one yet to come in the BMW."