Star jockey Craig Williams believes the preparation given to gun filly Norzita could prove a masterstroke in the Group One Doncaster Mile on Saturday.

Norzita heads into the famous 1600m handicap at Randwick off a Group One win in the Vinery Stud Stakes and Williams believes having raced over 2000m last start will stand the Bart Cummings-trained filly in good stead.

The internationally-successful Williams, who is chasing his first Doncaster win with his first ride on Norzita, said it was good to get a feel of the filly in trackwork on Saturday morning ahead of $2 million race.

"Most importantly I'm happy with the way she has gone into the Doncaster," Williams said.

"I actually love their idea of going to 2000 (metres) and coming back to the mile, especially for a race like the Doncaster which has always proven to be a really tough mile.

"I reckon that might end up being the winning formula - her preparation into it."

Two of the past three Doncaster winners - Sacred Choice in 2011 and Rangirangdoo in 2010 - had their final race before the Doncaster in the Ranvet Stakes over 2000m.

Last year's runner-up Shoot Out also came back from the 2000m of the Ranvet to beat all bar More Joyous in the Doncaster.

Pierro, winner of the Canterbury Stakes and George Ryder Stakes at Group One weight-for-age level this campaign, is the $2 TAB fixed odds favourite with Norzita at $8 and Shoot Out $13 ahead of Tuesday's barrier draw.

Glen Boss, the most successful jockey in Doncaster history with five wins, hopes for an inside draw with four-year-old Streama to give him a better chance of adding to his record.

Boss didn't ride at either the Golden Slipper or Australian Derby meetings in Sydney but heads to Randwick this week believing Streama has a good profile going into the race, dropping in weight from her recent starts.

"Pierro is obviously the real measuring stick. Three-year-olds have been so dominant in every race this year so you'd probably nearly expect the same again, but she (Streama) has been running well with big weights and not having the best draws," Boss said.

"If she can draw a low gate and I can get her into a spot and park her, I'm tipping that she'll run very well.

"Her best win was the Flight Stakes over the mile there, and Guy Walter is in flying form. His horses are all going great."