Australian punters wanting to back Black Caviar at a not too prohibitive quote have the chance to do so with UK bookmakers who have opened betting on the Group One Diamond Jubilee Stakes at Royal Ascot on June 23.The world's highest-rated sprinter is at odds of 4-6 ($1.67) with leading UK bookmaker William Hill.That is the best price offered on the unbeaten mare since she was sent out $1.90 favourite for the 2010 Patinack Farm Classic at Flemington 12 starts back.The best price she has started a

Australian punters wanting to back Black Caviar at a not too prohibitive quote have the chance to do so with UK bookmakers who have opened betting on the Group One Diamond Jubilee Stakes at Royal Ascot on June 23.

The world's highest-rated sprinter is at odds of 4-6 ($1.67) with leading UK bookmaker William Hill.

That is the best price offered on the unbeaten mare since she was sent out $1.90 favourite for the 2010 Patinack Farm Classic at Flemington 12 starts back.

The best price she has started at since was $1.28 when winning the 2011 Lightning Stakes.

Black Caviar is currently being served up at $1.04 by TAB Sportsbet for Saturday's Sportingbet Classic (1200m) at Morphettville.

However to create more betting interest, TAB Sportsbet has come up with some creative markets such as a head-to-head contest between Black Caviar and Atlantic Jewel who is the $1.22 favourite for Saturday's Group One All Aged Stakes at Randwick.

Punters have to choose which of the two unbeaten horses will win by the bigger margin on Saturday with Black Caviar at $1.40 and Atlantic Jewel at $3.

In her 19 wins so far Black Caviar has an average winning margin of just on 3.5 lengths with Atlantic Jewel's average just over three lengths in her six wins.

Black Caviar will create an Australasian record of 20 straight metropolitan wins if she captures her 10th Group One success on Saturday.

She is being quoted at $1.90 to win by four lengths or more and $1.90 for less than four lengths or gets beaten.

One corporate bookmaker was offering this novel market: Will Luke Nolen use the whip on Black Caviar? $1.40 No, $2.80 Yes.

Nolen, who has been aboard Black Caviar in her last 11 wins, eight Group Ones included, and 16 wins in all, showed respect for the Mark Kavanagh-trained filly Atlantic Jewel.

"Kav's filly, she's starting to bridge the gap, she's a very exciting horse too," Nolen told Radio Sport National.

"It's wonderful that she'll probably be able to carry the torch post-Black Caviar's career."

Atlantic Jewel's jockey Michael Rodd told AAP he didn't want to be drawn into a comparison with the great mare.

"Black Caviar is a freak and probably a once in lifetime horse," Rodd said.

"To be drawing comparisons with them, especially at this time of their careers, can't be done because they are two different horses.

"She (Atlantic Jewel) has got a helluva lot of ability and a huge future but I want to stay away from that comparison with Black Caviar.

Rodd said it was also unlikely that two horses would ever race each other.

"It is something they will talk about and for ages but it will never happen," he said.

"She (Atlantic Jewel) is probably best at a mile and Black Caviar is probably best at 1200 (metres)."