Weight of history on Authorized but Frankie can pull off classic triumph

Backroom boys such as 'test driver' Adrian McCarthy can help Dettori land Europe's greatest middle-distance prize. By Sue Montgomery

Should Authorized win the 86th Prix de l'Arc de Triomphe today, Frankie Dettori and Peter Chapple-Hyam will enthusiastically, but graciously, receive the plaudits that are their due. And, because behind every superb individual performance on the racecourse lies a team effort, both will rightly deflect praise to the backroom boys. To men like Alex Cairns, head lad at Chapple-Hyam's St Gatien stables in Newmarket; like Noel O'Connor, Authorized's devoted personal valet; like "roadie" Ronan Meehan, who oversees the travelling and has been in France since Thursday.

And like Adrian McCarthy, who has done the fine-tuning for Dettori. At home, O'Connor rides Authorized at exercise, the routine daily leg-stretch; McCarthy is in the saddle on work mornings, when the serious business gets done, when pressure is applied, when the horse gets to learn about racing and the trainer gets to learn about the horse. In Formula One terms, McCarthy is the test driver. And no flying dismounts.

A good work-rider, who knows what he is feeling and can give intelligent feedback, is essential to any trainer. Last season, when Authorized was no more than a highly promising juvenile, O'Connor did the job. This year, as a genuine Classic contender, the more experienced McCarthy took over the responsibility of the putative star's education and has felt the colt grow and develop under him, month by month, physically and mentally.

"Noel told me he was a good one," he said, "but to start with he didn't give me the impression that he'd be outstanding. He'd always work the same, he'd go past his lead horse easily but then feel he'd done enough, and not do much more. He was babyish, lazy, a bit dumb. Yes, as time went on he got better, but even before the Derby he was a bit like that. Immature. So it just shows how good he is to have won the Derby like he did."

Authorized romped home by five lengths at Epsom, experienced his first three-year-old reverse at the hands of the cannily ridden Notnowcato in the Eclipse Stakes, and bounced back with an authoritative defeat of top-class Dylan Thomas in the York International. With every race, he has become more streetwise, and more aware of his capabilities and status.

"Horses start to know that they're good," said McCarthy. "It's a confidence thing. He used to be quiet in his box when I'd saddle him up. Now he's there waiting at the door, and he tries to eat you. He's grown up; he understands life a bit more, he's fitter, he's developed muscles and grown into his big frame. He's not a boy any more, he's a man."

Authorized has inherited the imposing physique of his sire, Montjeu, and much of his talent but, happily, none of his quirks. "Like a lot of Montjeus he goes along with his head up, and you've got plenty of horse in front of you," said McCarthy. "Even at the walk, you can feel his massive stride, almost pulling you along. But he's straightforward. You ask him to do something, he'll do it, no arguments."

It is in the past month that McCarthy has felt the most marked change in the powerful bay. "One morning on the Limekilns," he said, "he started really tugging at me, so much so that I had to let him go sooner than I'd wanted. And then last Tuesday, in his last bit of work, what he gave me was the best he's ever given me.

"I pulled him out from behind his lead horse and he went six lengths clear and kept going. I didn't have to change my hands and get hold of him, just gave him a squeeze. He has such a high cruising speed and when he quickens he does it by lengthening. You can feel it, he seems to get longer and lower and suddenly you're going faster."

Catterick-born McCarthy, 28, travelled the world with his army family – he learned to ride in Germany – before finding a base in Newmarket, a graduate of the racing school there. He is not just a work-rider; he is a jockey, with nine winners to his credit this year, though most of his rides tend to be lowly beasts making up the numbers.

"Not many riders, champion jockeys or not, will know what it feels like to ride one as good as Authorized, and I don't suppose I'll be lucky enough to again," he said. "But to sit on one like him in the morning simply makes your day."

As well as Dettori, Authorized will carry the weight of history this afternoon. Of the 19 Derby winners to have contested the Arc as three-year-olds before today, only Sea-Bird, Mill Reef, Lammtarra and Sinndar have succeeded. Six others – Santa Claus, Sir Ivor, Nijinsky, Troy, Shahrastani and High Chaparral – have finished in the money. Most, as Authorized will do, have started favourite.

Chapple-Hyam's previous Epsom hero, Dr Devious, finished sixth but this one is a much better horse. And perhaps the race owes the trainer one. Of his other runners, White Muzzle was unlucky twice, and Polaris Flight was fatally injured. Authorized can redress the balance to give Dettori Europe's greatest middle-distance prize for a fourth time.

Today's 12-strong line-up – four from France, four from Ireland, three from Britain and one from Germany – is one of the smallest in the modern era. The four Irish raiders are all from one yard, that of Aidan O'Brien. His challenge is led by the two Irish Derby winners, this year's victor Soldier Of Fortune and four-year-old Dylan Thomas, trying for the first King George-Arc double since Lammtarra 12 years ago.

As far as the betting indicates, the home side's defence will be led by Zambezi Sun. The only filly in the field is Mandesha and although the Arc has been won 16 times by a female, the last to do so was Urban Sea 14 years ago. But since then several of the sisterhood have knocked on the door, and course-and-distance winner Mandesha makes each-way appeal.

Derby winners in the Arc

First: Relko, 1963

After winning the Derby by six lengths, and controversially keeping it after failing a dope test, Relko started 9-10 favourite for the first tape-started Arc. Sadly, he was greeted by jeers as he finished in only sixth place.

Best: Sea-Bird, 1965

Probably the best horse ever to race in Europe and one of the few to win a Derby on the bridle, the 12-10 favourite produced a devastating solo tour de force to win his Arc.

Shock: Nijinsky 1970

At 4-10, Nijinsky was not the hottest losing Arc favourite – that was 1-10 shot Ardan in 1945 – but his head defeat by Sassafras, the first of his career, is the upset that sticks in the mind.

Unique: Mill Reef 1971

Mill Reef became the first, and still only, horse to complete the great middle-distance four-timer of the Derby, Eclipse Stakes, King George VI & Queen Elizabeth Stakes and the Arc. At Longchamp he justified his 7-10 starting price with a scintillating three-length win.

Watch the Prix de L'Arc de Triomphe on BBC2 at 3.40pm. Full coverage starts at 12.30pm