Chris McGrath: Ground-breaking win for Tiago can bury depressing memories of dirt era

If you wander among the acacia and palms of the Santa Anita stabling complex you may come across a plaque on the green clapboard wall of Barn 38. It records that this humble shed, between 1937 and 1940, was where Tom Smith housed Seabiscuit, the rags-to-riches champion whose example helped to renew the self-belief of a nation.

Seabiscuit was twice beaten in the Santa Anita Handicap – once when Red Pollard, who had never disclosed the loss of sight in one eye, failed to spot the late arrival of Rosemont. But after an unfeasible return from injury, in 1940, Seabiscuit finally landed "the Hundred Grander" on his final start, in front of 78,000 joyously partisan Californians.

Nearly seven decades later, with a total of $25m at stake during the meeting, some of the world's best thoroughbreds are still coming here in search of the big money. This time, however, the timeless, Art Deco grandstand will witness the start of a brave new epoch in the chronicles of the international sport.

Last year, in the deluges at Monmouth Park, the Breeders' Cup reached a critical crossroads. Its billing as the World Thoroughbred Championships already depended almost entirely on Aidan O'Brien's patrons at Coolmore Stud, and they experienced a harrowing day. In a vile slop, they lost one of their most cherished horses in George Washington. A similar disaster had already claimed one popular champion in Barbaro, and another followed when Eight Belles collapsed grotesquely after finishing second in the Kentucky Derby. It was time for the American sport to examine its conscience.

California had already acted, replacing its dirt tracks with safer, synthetic material. And the arrival here of the Breeders' Cup, in its silver anniversary year, marks an authentic fresh start. The meeting has drawn no fewer than 35 overseas raiders – and several of them are going in "dirt" races, where many previously feared to tread. Quite literally, they are breaking new ground.

For John Gosden, of course, this is a familiar environment. He began his training career here, and won the inaugural Breeders' Cup Mile across town at Hollywood Park. As one of the game's more cerebral observers, he has caught the significance of the moment. Gosden argues that the new surface may mean we no longer salute turf champions and dirt champions, but champions full stop. In turn, the schism in the thoroughbred's bloodlines could be sealed. In the circumstances, he implied it would have been a dereliction of duty not to let Raven's Pass go for the Classic.

It is an audacious choice because his colt has never run beyond a mile and, regardless of the surface, the extra two furlongs will be uncharted. And while he would have been favourite for the Mile, Raven's Pass meets more formidable rivals in the Classic – not least Curlin, the richest performer in the sport's history.

Bar a brief, failed experiment on turf, Curlin has proved invincible over the past year, taking both of the world's most valuable prizes – this race, at Monmouth, and the Dubai World Cup by a record margin. But he has yet to try an artificial surface, and has been less imperious in his last couple of starts. Perhaps two gruelling campaigns are just beginning to show on the petrol gauge.

Henrythenavigator and Duke Of Marmalade also come here at the end of a tough season and, like many in Ballydoyle's party, have been looking a little hirsute in the morning heat. Like his longstanding rival, Raven's Pass, Henrythenavigator must demonstrate stamina, which makes the 12-1 against the dependable Duke Of Marmalade far more tempting.

While the Japanese introduce an unquantifiable talent in Casino Drive, it is easy to envisage a result that would cause reactionaries in the American sport to deplore the end of the dirt era. A case in point might be Tiago (11.45), who looks a knockout each-way at 33-1. By a sire whose stock improve with age, he is at home on this track and his last run intimated progress after an interrupted campaign.

However the raiders fare on the synthetic track, the Americans will be no less vulnerable than usual in the turf races. And there are fresh opportunities, too: Diabolical (6.50), for instance, can redeem an eponymous year for his stable in the new turf Sprint. Stamina is another issue for the locals, so Sixties Icon (6.50) has prospects in the inaugural Marathon, while both failings are often apparent in the Turf itself. The ground may be too firm for Soldier Of Fortune and Conduit, while Winchester must prove his stamina, so preference is for Eagle Mountain (11.00), after that remarkable debut for his new trainer over a mile. The French filly, Goldikova, is favourite for a Mile weakened by the allure of the Classic, but the defending champion, Kip Deville (8.15), is fancied to see off all comers once again.

All in all, far too many of the raiders seem to have come here on an extempore basis. It was at Santa Anita, remember, that Dancing Brave himself ran out of gas in the third Breeders' Cup. Experience is supposed to have taught trainers that they cannot come here as an afterthought. But then history has a habit of repeating itself. We see that all the time. And if that means we have to deal with another Depression, let's hope that we might at least come up with another Seabiscuit, as well.

Master of the horse looks the ace in O'Brien Derby pack

A new generation of Coolmore sires – Galileo, Montjeu and High Chaparral – is altering the complexion of the horses at Ballydoyle. While he has fewer Royal Ascot juveniles, Aidan O'Brien now has literally dozens bred to win a Derby. It duly seems significant he should have identified Masterofthehorse as his most eligible candidate for today's Racing Post Trophy at Doncaster.

Three of the last seven winners have gone on to win at Epsom the following June, including High Chaparral, and Masterofthehorse remains a feasible type despite defeat at the Curragh last time. Caught at the rear when a steady pace picked up, he kept on to be beaten barely half a length. There could be no more fitting winner of the British season's final Group One race.

With 21 such prizes on the board, O'Brien has been running out of steam in his quest to pass Bobby Frankel's record of 25. Tomorrow Yeats must retrieve his peak for the Prix Royal Oak at Longchamp – scene of a dismal run last time. O'Brien also has his work cut out at Santa Anita and is on a five-year barren streak at the Breeders' Cup.