The highly-rated filly is already acclimatising at Churchill Downs – home of the Kentucky Derby – ahead of Friday night’s race that is billed as the world championships of racing.
The contest precedes Saturday’s Charlie Hall Chase, the feature race of the year at Wetherby, where good ground is expected to suit the Ellison-trained Definitly Red.
It will be a big 24-hour period for Malton-based Ellison who is regarded as one of the country’s top dual purpose trainers with more than 1,000 winners to his name under both codes. He has previously had runners in the Melbourne Cup courtesy of 2011 Ebor hero Moyenne Corniche and Saptapadi.
But the Breeders’ Cup is a different proposition for Ellison, who will be saddling The Mackem Bullet for a final time.
Second in the Lowther Stakes at York’s Ebor festival, she was runner-up in the Group One Cheveley Park Stakes at Newmarket and will, once again, be ridden by jockey of the season Oisin Murphy.
“It’s what every trainer wants more than anything, coming here. That’s what you’re in it for,” said Ellison after supervising the work of The Mackem Bullet in Kentucky.
“I’ve taken a horse to the Melbourne Cup in the past, but the nervous excitement I’ve had for the last few weeks over my filly has been quite incredible.
“She is stepping up in trip to a mile, but Oisin, who has ridden her twice, and Ben (Curtis) the once, both say she wants further.”
He added: “I think she was a bit unlucky on her first couple of starts, but then it all clicked and she’s never looked back.
“I know Oisin fancies her, and in fairness she has got the best form of the English fillies in the race.
“The owner Brian Robe is a Sunderland fan, and I’m a Geordie – but there’s no angst between us.
“Brian has in fact sold the filly to a Japanese (Katsumi Yoshida) – and under the arrangement that Brian has with the new owner this will be her last run for me.
“She is staying out here for a season’s more racing, but after that will she end up at stud in Japan.”
Hambleton trainer Kevin Ryan’s East – unbeaten from two starts and the mount of Jamie Spencer – is a second Yorkshire contender.
Meanwhile, Definitly Red’s probable rivals in the Charlie Hall Chase look set to feature the Tom George-trained Double Shuffle.
Although winless for the best part of two years, the eight-year-old ran some tremendous races in defeat last season – most notably pushing Might Bite close in the King George VI Chase at Kempton on Boxing Day.
He was disappointing behind the same rival in the Betway Bowl at Aintree, and rounded off his campaign with another below-par run at Sandown, but George is pleased with his charge.
“Double Shuffle is in great form at home, and we are happy with him,” said the trainer.
“He, of course, ran a cracker in the King George last season – which was a great run – and we had him very ready that day.
“If the rain stays away the Charlie Hall looks a good first race to aim for. Good ground and three miles at Wetherby should suit. Kempton and another tilt at the King George is probably one of the next moves after that.”