A look at the task confronting Imperatriz in this weekend’s Newmarket Handicap
Much of the talk in the lead-up to Saturday's Newmarket Handicap has centred around Imperatriz and the task confronting her as topweight in Australia's most famous sprint.
The five-year-old is being asked to emulate Black Caviar and win the 1200-metre Flemington feature with 58kg.
That is not the mares' weight-carrying record – Pendant still owns that after lumping the equivalent of 60.5kg to victory in 1904 – but it is the performance all mares are now judged against.
Black Caviar made a mockery of her Newmarket weight, cruising home by three lengths in near-track-record time (1:07.32) for what was her third Group 1 win at her 10th career start.
Imperatriz will not retire undefeated, but she takes a bulkier CV into the Newmarket than Black Caviar did.
Half of the Mark Walker-trained mare's 18 wins have come at Group 1 level, five of them during a six-race winning streak she will take into Saturday's race.
That will make her the best-credentialled horse to contest a Newmarket since the Group 1 classification system was introduced in 1979.
Mahogany is the most prolific Group 1 performer to have run in a Newmarket, carrying 59.5kg into fourth position in the 1997 edition as an eight-time Group 1 winner.
He was 9.5kg over the limit weight, while Black Caviar had 8kg more than her lightest-weighted rivals, one of whom was runner-up Crystal Lily.
Imperatriz is just 6.5kg over the limit, which will be carried by three-year-old colt Cylinder.
Mahogany and Black Caviar are among 19 horses to carry at least 58kg in a Newmarket since 1979 with Shaftesbury Avenue (58kg, 1991) and Hay List (58.5kg, 2012) the other winners.
Runners-up Always Welcome (58kg, 1979) and Hareeba (58.5kg, 1995), plus 2016 third placegetter Chautauqua (58kg), are the only others to place.
Black Caviar stands alone as the only mare to contest a Newmarket with 58kg, though.
The next highest weight carried to victory by a mare in the metric era is Maybe Mahal's 56.5kg in 1978 with Ortensia the only other mare since to contest a Newmarket with 56.5kg.
Ortensia finished 12th in the 2013 edition won by Shamexpress.
Seven other mares have carried at least 55.5kg in a Newmarket this millennium with Miss Andretti, who carried 56kg to victory in 2007, the only to finish in the top six.
Bella Nipotina will also join them on Saturday with the six-year-old to carry 55.5kg in a rare Newmarket where mares dominate the top of the racebook.
Four-year-old entire Buenos Noches also has 55.5kg, but the next three in the weights are all mares; Espiona (54.5kg) – who has since been scratched – Ruthless Dame (53.5kg) and Magic Time (53kg).
