Racing: Aidan O'brien Ready for Competition in Dallas

Aidan O'Brien has been the master of Ballydoyle for nearly 10 years, an alpha-grade player in a pitiless game, but there is still a beguiling sense of fragility about him. Perhaps it is the soft voice, or the wire spectacles, or the slim frame that hints at his former status as a champion amateur jockey over jumps.

It is nonsense, of course. What lies beneath is a sense of purpose spun from steel and a focus and determination that would do credit to an Olympic athlete or a chief executive on Wall Street. And as the trainer for Europe's most business-minded bloodstock operation, his job shares elements with both.

It has all the pressure too, though one would never have guessed as O'Brien relaxed with his wife and four children here at Lone Star Park in Dallas on Wednesday afternoon. There was constant chatter and laughter and the sense of a family holiday rather than the run-up to the richest one-day event in sport.

The next day they turned up at the track wearing Stetsons. Work-life balance? O'Brien seems to have it cracked.

It is not a suggestion he takes too seriously. "Nobody ever has it cracked," he says. "This is a very fickle game, horses aren't programmed and just because you've got a system that works it doesn't mean that it's going to work every year.

"As a family we go everywhere together, we live and work together and obviously everyone is very involved and knows what's happening day in and day out. It's very rare that you have to explain anything, because everything is being discussed all the time, with Anne-Marie [his wife], the kids, everyone."

To date the 2004 season has not been one to match the campaigns of 2001 or 2002, when O'Brien became the first Irish-based trainer for decades to win the British championship. But that same fickleness he appreciates so keenly means that a few hours in Texas today could yet make it a year to remember.

O'Brien has five runners at the Breeders' Cup, one in each of the three turf races and one each in the two juvenile events on dirt. (The whole of Britain, by contrast, is fielding only two.) This, a grand total of nine minutes of frantic action, is what he works and lives for.

None of his runners is likely to start favourite, though Powerscourt will be a well-fancied second favourite for the $2m (£1.1m) Turf. But even without favourites the need to succeed remains.

"There's always pressure at a meeting like this, because every race is a big race for these horses," he says. "They're born, bred and reared to be champions and what we just try to do is be sure not to do them any harm mentally or physically, because they're not going to be stallions if we do.

"Even if they're not going to be good enough to stand at Coolmore [John Magnier's stud, which owns Ballydoyle], then they still need to pass a vet and have a race record to be worth money. So every race matters and we don't really ever think about anything else. When you have so many of them, it's 24 hours a day."

O'Brien has never been one to carry on regardless when things are not going his way. He is always ready to question his own methods, which is perhaps what sets him apart from so many other trainers.

"Everyone likes winning and, if you're not winning, then you'll keep looking to find out why," he says. "Sometimes a lot of thought has to go into finding out what's wrong. There's so many variables and little shifts that can make a big difference, from the climate to the people working with the horses.

"We've never taken anything for granted but, if you go to bed happy that you've done your best that day, and you really believe that every decision you made was the right one, no one can do any more than that."

O'Brien is a great rarity, a driven genius with the perfect channel for his talent and a family to keep him grounded. Expect them all to find their reward at least once today.