Ruby Tuesday won’t just be racing to garner black type for her connections when she contests Sydney’s final stakes race of the season.

She will also be bidding to fill the coffers for breast cancer research.

Ten per cent of the mare’s prizemoney is donated to the cause and if Ruby Tuesday can bank the $82,500 winner’s cheque for Saturday’s Listed Winter Challenge (1500m) at Rosehill, it will take her total contributions to the charity to over $45,000.

A top-three finish would also boost her residual value, and that is the driving force behind trainer Gary Portelli’s decision to start her in the feature, rather than an easier assignment.

“We’re trying desperately to get black type for her owners and for breast cancer research, with ten per cent of the prizemoney going there,” Portelli said.

“If she was to get black type and go on the open market as a broodmare, she’d bring plenty of money, so that’s the plan of attack.

“We probably could have put her in something else, but we haven’t got too many races left in her, so we decided to have a throw at the stumps.”

A seven-time winner, Ruby Tuesday’s best result in stakes grade was a fourth in the Group 3 Belle of The Turf Stakes during the summer.

She heads into Saturday’s race second-up after doing her best work late when sixth behind Wewillrock over an unsuitable 1200m at Randwick last start, an effort Portelli said had plenty of merit.

“She ran home her last 600 (metres) in 33 (seconds) neat,” Portelli said.

“She was a long way off them and chasing before the 600, so she ran really well and we’re very happy with the way she has come through it.

“She has drawn OK (barrier 10) for the 1500, it’s a nice run down the back so hopefully she gets in somewhere.”

Ruby Tuesday is an $18 chance for the Winter Challenge with markets headed by the Ciaron Maher and David Eustace-trained Semana ($3.80 fav), although the first emergency needs a scratching to make the field.