As well as keeping her perfect winning sequence intact at Randwick on Saturday, champion sprinter Black Caviar is set to maintain her record for turning foul weather to fair.

None of the mare's 24 starts has been on anything worse than a dead track - and right on cue, the Sydney weather is turning in her favour.

"She's got an amazing ability to find dry tracks," trainer Peter Moody said.

"In the lead-up to this meeting two years ago the Golden Slipper was run on a bog the week before and she struck a dead track at Randwick."

At her next start in that campaign Black Caviar won on a dead track at Doomben after the previous weekend's Eagle Farm meeting had been washed out.

Moody has insisted Black Caviar will not appear in Saturday's TJ Smith Stakes if the Randwick track is worse than a slow 6.

Heavy rain on Tuesday had the track rated a heavy 8 but had improved on Wednesday and was on the way to a slow rating by Thursday.

Because the TJ Smith is to be run as the final race of nine on Saturday, Moody was particularly concerned over a wet surface having been chopped up by the preceding eight races.

"Even though she's won trials on slow and heavy tracks, I don't see any reasons to risk her in a race on a wet track," he said.

"I think she'd probably handle the slow and heavy, but do we need to find out.

"I just don't think there's any reason to risk her on a wet track."

The improving weather had encouraged bookmakers to post the world champion at $1.10 in the TJ Smith, a shorter quote than when she won the same race two years ago.

In a win regarded as one of the best of her 24, Black Caviar started at $1.14 when she gave Hay List a long start and a beating.