Classic countdown: why Aidan O'Brien may divide his aces

There are 22 horses left in the Betfred Derby and Aidan O’Brien is responsible for ten of them.

Action, Amadeus Mozart, Benvenuto Cellini, Causeway, Christmas Day, Constitution River, Endorsement, Hawk Mountain, Pierre Bonnard and Proposition are not all going to be representing him at Epsom on Saturday week, but 24 hours can be a long while in the life of a racehorse and the trainer who knows a thing or 11 about winning the premier Classic likes to keep all available options open.

The most intriguing of the Ballydoyle Class Of 2026 are Benvenuto Cellini and Constitution River, with the latter briefly usurping his stablemate at the head of the ante-post betting on Sunday morning after a sudden market move.

That fuelled hopes that the pair who lit up the Boodles May Festival at Chester may be set for a blockbuster clash, but O’Brien poured cold water on that possibility a few hours later, saying he “presumed” Constitution River was still more likely to head to the Prix du Jockey Club (French Derby) at Chantilly. He didn’t completely close the door on the colt being rerouted to Epsom, but he kind of did for those familiar with his yes, no, maybe way of answering.

The Prix du Jockey Club was inspired by the Derby and run over the same trip of mile and a half for the first 169 years of its existence.

But that changed in 2005 when it was cut in distance to 1m 2½f. Édouard de Rothschild, the president of France Galop, and director-general Louis Romanet yearned for greater competition after a sequence of weakish renewals and went out of their way to entice top milers, rather than the usual middle-distance stayers.

It was a controversial move scorned by traditionalists but it was instantly rewarded with outstanding British raider Shamardal, who had previously won the French 2000 Guineas, edging out Hurricane Run, who would subsequently land five races at the top level, in the first newlook edition.

O’Brien’s challenger in that 2005 renewal was Scorpion, who beat only one home. That set something of a pattern, with the trainer’s first 31 runners in the race, up until 2020, all making little impact, despite him fielding four favourites or joint-favourites.

St Mark’s Basilica finally hit the target for him in 2021, and Camille Pissaro followed suit 12 months ago. Neither would run over a mile and a half before being retired to stud. Overall, he’s had two winners from 39 runners in the race (5.12%).

Constitution River is a handsome son of Wootton Bassett, being the first foal of the once-raced Chuppy. Her sire was Le Havre, who won the 2009 Prix du Jockey Club when having his first (and only) run beyond a mile, while her grandsire was Noverre, who never won beyond a mile.

There would certainly be some doubt about Constitution River being fully effective over a mile and a half, at least on breeding, and a quick flick at his numbers on RaceiQ merely illustrates he is a horse with a stack of pace.

The Derby entries have 85 of their runs logged in the RaceiQ database and Constitution River is responsible for the two top speeds (41.91mph and 41.84mph) of them all, plus the fastest furlong (10.81sec) plus third fastest furlong (10.8sec).

He had never previously run beyond 7f before tackling this month’s Dee Stakes and a steady first half of the race, which took him 67.68sec to complete, played into his hands. In the second half, he was able to go through the gears, reeling off five successive sub 12-second furlongs and coming home in 58.87sec despite Ryan Moore easing down. The combination stopped the clock in a record time of 2min 06.54sec.

RaceiQ gave him a Time Index of 9.9, when the meeting average was 8.2. The had him winning in a time 5.12sec quicker than their Par, albeit a suspect going description of “good”, when it was almost certainly good to firm or quicker, skewed that.

If Constitution River runs at Epsom, he will probably have to sustain his gallop for about another 30 seconds on ground unlikely to be any quicker that he encountered on the Roodee.

None of O’Brien’s 11 previous Derby winners ran in the Dee beforehand, and we are into guessing territory as to whether he will get the longer trip, with his stride data doing little to make the grey area any clearer.

As a basic rule of thumb, horses with a low stride cadence preserve energy and have a better chance of staying further. Those with a high stride cadence are basically running at much higher revs and, consequently, are more likely to be sprinters.

The first three home in the Derby last year all had the lowest average strides per second – between 2.12 and 2.13. The maximum stride length of the winner, Lambourn, was 8.06 metres, with the three longest striders in the line-up finishing in first four.

Twelve months earlier, the long striders had enjoyed a one-two with City Of Troy (7.98 metres maximum) beating Ambiente Friendly (7.84). And third placed Los Angeles (7.69) was fourth highest. City Of Troy averaged 2.13 strides per second, a smidgeon off being lowest.

Constitution River’s average stride frequency at Chester was 2.21, with his peak stride being 2.34 and minimum stride 2.13. At full stretch, his maximum stride measured 7.95 metres.

To be fully effective at Epsom, you would imagine him needing to bring his average stride down about 3%, which is not impossible but a tad unlikely. Equally, he’s got that huge “speed” weapon in his armoury; and he would not be the first Derby winner to triumph despite being even better qualified to win races over shorter.

But stretching elastic bands in the Derby comes with risks attached and you can see why O’Brien and messrs Magnier, Tabor and Smith may resist peaking under his bonnet, especially when they have Benvenuto Cellini to call upon. 

This striking chestnut with a wonky blaze stands out from the crowd in more ways than one.

You can quibble with the quality of his form, but not the manner of his wins; the evidence of the clock; or what the data is screaming about his untapped reserves of staying power.

His two-year-old exploits included a runaway victory in the KPMG Champions Juvenile Stakes over a mile at Leopardstown and that’s a race that O’Brien favours for his would-be Derby horses, having won it with Australia and Auguste Rodin in the past.

And he kicked off his campaign this year with a similar wide-margin success in the Chester Vase; a race Ruler Of The World, Wings Of Eagles and Lambourn contested for the stable before going on to glory at Epsom.

The common denominator between Leopardstown and Chester was a sound surface, which Benvenuto Cellini devoured, as befits a long-striding son of Frankel whose dam blitzed the opposition as a juvenile at the Breeders’ Cup in 2018.

There is not a horse in the Derby who strides more like an out-and-out stayer. He is the owner of all three lowest stride averages in the race – 2.04 per second at Chester, 2.1 at Killarney and 2.11 at Leopardstown.

His cadence is extremely low and, on paper at least, you would imagine him having no bother getting further. Possibly much further.

For instance, Benvenuto Cellini’s stablemate, Scandinavia, favourite for next month’s Gold Cup at Royal Ascot, averaged 2.11 strides per second when winning the St Leger last season, and 2.12 when previously landing the Goodwood Cup.

But we know this colt is not a slowcoach and at full stretch he can eat up ground like no others. His stride reached a maximum of 8.39 metres as a juvenile, when losing his maiden tag at Killarney, and the tight nature of Chester did not prevent him hitting 8.36. He averaged 7.98 in the latter race, a distance many horses cannot ever hope to obtain, even when at maximum capacity.

Little wonder, perhaps, that he got lost on a muddy surface in the Futurity at the end of last year. Those conditions clearly blunted him.

Benvenuto Cellini in full flow is a sight to behold, and we can expect more of the same provided Epsom’s twists, turns and contours do not throw him off balance. He looked nimble enough at Chester, even if that was Plan B for him (Plan A had been the Blue Riband Trial at Epsom but O’Brien had a reshuffle when that race got delayed by a week).

His winning time in the Chester Vase was the quickest since 2002; almost 5sec better than Lambourn the year before, albeit on faster terrain. He got a RaceiQ Time Index of 9.6, when the meeting average was 8, and signed off with four successive “fast” furlongs, which he completed in 47.31sec.

He's blessed with speed and stamina; has had a good prep and likely to have the services of Ryan Moore.

Racing fans would love to see two of the most exciting middle-distance horses in training lock horns, but it could be that only the staff at Ballydoyle will see them in close proximity. At least for a little while longer.