The G2 Park Hill Stakes at Doncaster on Thursday over the extended mile and three quarters is the world's most historic and important distaff-only staying race and may give Sir Henry Cecil his sixth win in the famous fillies and mares event.

Founded in 1839, it is run over the St Leger course and has been popularly referred to as "the fillies' St Leger" but is not really applicable since the race was opened to horses older than three in 1990.

Nine have been declared for this year's race, with the likely favourite Wild Coco, Sir Henry Cecil's representative.

The lightly-raced four-year-old has yet to race at G2 level but warmed up in fine style at Goodwood last month with a wide-margin victory in the mile-and-three-quarter Ishares Fillies' Stakes, her first G3 success.

Her market rival is likely to be Estimate, the highest-rated of the seven three-year-olds in the field.

The filly by the just deceased sire Monsun was three lengths third to Wild Coco at Goodwood, but is likely to be better suited by the greater test of stamina of the Park Hill Stakes over a more demanding course.

Estimate, a half-sister to Ascot Gold Cup winner Enzeli, was bred by the Aga Khan but races in the Royal colours. The Queen has previously been successful in the Park Hill Stakes with Example in 1971 and with Almeria in 1957.

Estimate's trainer Sir Michael Stoute has won the race four times, one less than Sir Henry Cecil, and also runs Monshak.

Another by Monsun, she won a mile-and-three-quarter handicap at Chester in July but refused to race behind St Leger candidate Guarantee at York last time out.

The Roger Varian-trained Ambivalent has yet to race beyond a mile and a half, but her pedigree suggests that she may cope with the step up in distance as she is a half-sister by Derby winner Authorized to Made In Japan, winner of the two-mile Triumph Hurdle at the Cheltenham Festival.

She stayed on well to beat last year's Park Hill Stakes runner-up Set To Music at Newmarket last month.

Kailani is the only filly in the field to have contested a classic this year, finishing seventh to Was in the Oaks after beating Park Hill Stakes rival Hazel Lavery by seven lengths at Newmarket in May.

She has since finished down the field in the Ribblesdale Stakes at Royal Ascot but, as another daughter of stamina influence Monsun, may be suited by the longer distance.

The sole Yorkshire-trained candidate is last year's fourth Cracking Lass, from the Richard Fahey stable.

The five-year-old was third in a Listed contest at York last month on her seasonal reappearance.