At 6.12 p.m. this evening the gates will open on the finest day's racing of the year in America. And of course by America the Americans really mean the world. And guess what folks? They're right.

Hell, even us Eur'peens are helping 'em with their boast. Sinndar's gone to his happy fate in a Kildare breeding shed but the other major names of the year from this side of the pond are over there in Looovulle.

Montjeu will be feeling no pain in the Turf, Petrushka will be hot in the race created to try and ease permanently-wounded European pride and that supposed toughie Crimplene will have to cope with the hardest mamas in the world in the Distaff.

Yep, the names we've been eulogising and fretting over all year are currently snoring their heads off at the Churchill Downs backstretch. And do you want to know something, they don't really matter. Ouch, rub that old-world ego.

You see Breeders' Cup day is an American gig. After all they created it 16 years ago, they stage it and they pay for it. Everything's bigger in the United States, but boy it has to be if you're going to be noticed. And today is all about getting racing noticed in the US. But in the land of the free that means colossal figures.

There's $14 million up for grabs today at the home of America's most famous race, the Kentucky Derby. The winner of the Classic alone will get over £1.5 million sterling. Hell, even the fifth horse gets £58,171. But look at the pay off.

The Breeders' Cup is on for four and a half hours on NBC. And live, too. That's coast to coast on a TV channel that doesn't have subscription wackos and psychos from the world's greatest democracy as its client base. Even the bible belt gazillions who believe horses equals betting which equals damnation watch NBC. These four and a half hours are the time of opportunity.

And the greatest pay-off is the Classic, run at 10.10. This is racing as America recognises it. A mile and a quarter on dirt. Once around the country's most famous track. Forget all that turf nonsense and fancy-ass fluting around on racecourses where the horses are beyond binocular vision. Here, the best horses run as fast they can for as long as they can for the best money. Go Baby Go!

The thing is the Irish have a stake in it this time. The Yanks are even a little worried about this Giant's Causeway horse, although of course they'd never let on. And there's Pine Dance trained by that guy Weld who travels horses all over the world. And there's another Irish trainer too, except for Niall O'Callaghan the Churchill Downs backstretch is home.

It has been so since he started training there 10 years ago. It's a further nine years back to when O'Callaghan first arrived in the US armed with $80 borrowed from his sister, plus three years experience picked up from spells with Paddy Prendergast Snr, his son Kevin and Jim Bolger.

Now 37, O'Callaghan regularly finishes in the top 50 of America's trainers each year. In 1999 the string he trained picked up almost $2.5 million in earnings. He also won his first Grade One race, the Coaching Club American Oaks. This year the earnings total is over $1.5 million despite a nightmare period up to April. And there's still Guided Tour in today's Classic.

It's American dream stuff and although there's enough of the accent and cheerful scepticism still remaining from O'Callaghan's West Cork upbringing in Castletownkennigh, he recognises how good the American way has been to him.

"I don't hear anybody crying out for me from home," laughs the thin and seemingly perpetually active figure. In the US it's hustle that counts. Hustle and enthusiasm. O'Callaghan knows better than anyone he would hardly have carved out such a career in Ireland where training badges seem to remain in the family.

As a result realism emerges from his every pore and he is the same when discussing the outsider Guided Tour, who is rated a 50 to 1chance by the odds-makers.

"It's cost us $80,000 to get him into the race and if he runs fourth we're into profit. If he runs third, we're into a major hit. He would double his earnings," says O'Callaghan, who has overseen the metamorphosis of a bone idle Guided Tour into a Breeders' Cup Guided Tour.

"He was ordinary at two, ordinary at three and ordinary as an early four-year-old. But since then he has surprised me big time. It started when he ran Vision And Verse (another Classic contender) to a neck here at Churchill Downs. Then he won two races here, won a Listed in Canada and an easy Grade Three in Ohio. Last time he was second in the Hawthorne Gold Cup and beat Golden Missile into third. Awesome Again won the Hawthorne before winning the Classic in 1998 and my horse is going forward all the time," he enthuses.

But realistically a Guided Tour Breeders' Cup Classic victory is unlikely and O'Callaghan knows it. But it's what he knows about his home track and dirt racing all over the US that makes him so interesting about Giant's Causeway's chance.

The Ballydoyle-Coolmore team have spent almost two years teaching Giant's Causeway to do one thing, which is to race in the highest class on grass. The Irish colt is accepted as a champion at that. But now he is being asked to return to his birthplace and race in an alien environment and on an alien surface against champions like Fusaichi Pegasus, Lemon Drop Kid and Tiznow. That's not so much a big ask as an ear-splitting holler.

"I've seen a lot of horses switched to dirt for the first time and 80 per cent of them won't do it," says O'Callaghan. "It's nothing to do with training. It's strictly traction. If a horse is well enough to run in a Group One on turf, he's well enough to run in a Group One on dirt, but what can happen is that the wheels will start to spin at the three-furlong pole if the horse isn't getting a hold on the dirt.

"But Giant's Causeway is fancied very strongly over here. Everybody gives him a chance of handling the dirt because his dam, Mariah's Storm beat the champion Serena's Song at Churchill Downs and his sire, Storm Cat did nothing but race on dirt too."

O'Callaghan believes the pace issue is overplayed - "it'll be a very decent clip but they won't go crazy" - and instead points to the presence of Fusaichi Pegasus, the $4 million yearling purchase who is now worth $70 million as a stallion to Coolmore, as a much more simple reason as to why Giant's Causeway and Pine Dance are up against it.

"If Fusaichi Pegasus runs his race I don't think the other American horses can beat him," he says. "He really is as good as he is talked up to be. I would say he is the best three-year-old we've seen over here in the last seven to eight years."

O'Callaghan feels that if anything beats Fusaichi it'll be Giant's Causeway - "if he can show the same form as he has on turf".

That's a substantial question and only one that the most substantial day the sport knows could demand a horse like Giant's Causeway to answer. In fact it's what the Breeders' Cup is all about. Except this time there's just a chance America's gig could end up playing an Irish tune.