If you were concerned about the O'Brien domination of the Irish Derby, led by Aidan and backed up by sons Joseph and Donnacha, then prepare yourself for more consternation in this Saturday's Coral-Eclipse Stakes. At Monday's confirmation stage only eight remained and one was added, leaving four from Ballydoyle – two of those, Hawk Mountain and Causeway, having also been supplemented for Sunday's Deutsches Derby – and one each from the younger O'Briens. Only three potential Eclipse runners are trained in Britain: the four-year-olds Saddadd and Gethin, and five-year-old Kings Gambit. Aidan O'Brien, who has already bagged 11 Group 1 wins this year, including all three 1,000 Guineas and Derbys of Britain, Ireland and France as well as the Prix de Diane, has the favourite in Constitution River (Wootton Bassett).Owen Burrows is giving it a rattle, having sent fourth-placed Raaheeb (Sea The Stars) to the Irish Derby on Sunday, and he trains Gethin, Britain's leading hope for the Eclipse, while Ralph Beckett, Andrew Balding, William Haggas, John and Thady Gosden, Karl Burke and Charlie Johnston all had a least one runner in an Epsom Classic. But still, from at least a dozen stables whose equine numbers run to three figures, there have been only 14 British runners in the Derby, Oaks and Irish Derby, plus one Derby runner each from Jane Chapple-Hyam and Faye Bramley, whose yards are smaller.So where are all the middle-distance horses? They haven't all been sold abroad, and it is not a case that they are not being bred, though numbers are admittedly in decline in that area. But even a snapshot of the recorded coverings from 2022, which led to this season's crop of three-year-olds, show that a number of stallions who have either won the Derby or have sired a Derby winner are not exactly standing around idle. For example, in that year, Australia covered 173 mares, while his fellow Derby winners and Derby sires Camelot and Sea The Stars covered 159 and 161. Frankel had 188 mares booked to him, Nathaniel covered 133, and the late Wootton Bassett, who has knocked on the door in both the Derby and the Oaks, had a book of 249. Dubawi and his champion son Night Of Thunder covered 165 and 180. Then there are the Derby winners who have largely joined the National Hunt sector, which include Golden Horn (152), Harzand (62), and Masar (82).Plainly, not every foal that resulted from one of those matings will have remained in Britain and Ireland, and many of them will turn out to be below black type standard, but there are plenty of other stallions out there who are also capable of getting decent middle-distance performers given the right mares, so why aren't more of their offspring filtering through to be given a chance in the better races?One conclusion we can draw is that turning horses who may have Classic potential into Classic runners is clearly easier said than done. Another conclusion to be drawn from the results of the Classics from pretty much every year this century is that Aidan O'Brien is a master at doing so. It is true that he has a seemingly inexhaustible supply of blue-blooded equine talent, but there are a handful of other stables which are almost similarly well blessed. What is also noticeable is that the Ballydoyle horses are generally kept busy at two. This weekend, while Benvenuto Cellini (Frankel) was beating the Derby winner Christmas Day (Camelot) in the Irish Derby, and being followed home by potential St Leger winner Pierre Bonnard (Camelot), O'Brien also sent out Alpha – a daughter of Sea The Stars and Alpha Centauri – to win her maiden decisively, having made her debut on June 4. She is now an early favourite for next year's fillies' Classics. Then there's Giant Sequoia, by Frankel and from the same family as Benvenuto Cellini, who also won on his second start after making his debut the day before Alpha. The colt, bred by Resolute Bloodstock, and owned by Resolute in partnership with Coolmore and Westerberg, is out of the Oaks runner-up Pink Dogwood (Camelot). All being well, we should expect to see him at Epsom and back at the Curragh next year. Roger Varian and his former housemate Owen Burrows will attempt to halt the O'Brien juggernaut at Sandown on Saturday, while Harry Charlton has supplemented King's Gambit to give Wathnan Racing two runners in the race. Ombudsman, beaten a neck in last year's Eclipse by three-year-old Delacroix, heads straight to York from his Ascot triumph for the Juddmonte International. A statuesque animal, he only made his debut three weeks after his contemporary City Of Troy had won the Derby on his fifth start.Ombudsman is now of course one of the most exciting horses in training anywhere in the world. A few years before him, Baaeed had a similar profile – a June debut at three before becoming a top four-year-old. Would they have reached such heights had they been pushed to do more earlier? Probably not, and while the Classics remain important tests, having high-class older horses around is equally important for the sport itself. It's a conundrum, leading to a debate which could run and run. This hack certainly doesn't have all, or any of, the answers, but if anyone would like to meet for some good-natured discussion on this subject during the festivities of next week's sales and race meeting in Newmarket then the first round is on me.Raiders of the ArcI have a feeling that the first person on a barstool alongside me could be Patrick Cooper, whose annual correspondence on the merits of shortening the Irish Derby to ten furlongs can be expected any time now. Among this year's general musings around the Classics has been the suggestion to move the Derby back a month or so – a change which Britain could not make unilaterally without the approval of its fellow member nations of the European Pattern Committee (EPC), some of whose own important black-type races would be affected by such an adjustment.“Tiens ma bière,” said France Galop boldly amid all these mutterings stage left, and proceeded to announce last week that the Prix de l'Arc de Triomphe would be open to geldings from 2027, subject to EPC approval. This has caused a predictable division in opinion. In the nay camp are some pretty big hitters, including John Magnier, Andre Fabre, Kirsten Rausing and Aidan O'Brien. The ayes may well have it, however, as the vote of France Galop board members was said to be overwhelmingly in support of the idea. Francis Graffard is among those to have welcomed the proposed change, and before anyone can say Calandagan and Goliath, it is of course important to reflect that Graffard won last year's race with the colt Daryz. John Magnier and Aidan O'Brien are opposed to geldings running in the Arc | Racingfotos What is perhaps unsettling is that, according to the comments made by vice president Arnaud de Seyssel to this publication last week, France Galop seems to have given up on the idea of the Arc being an important race when it comes to breeding. The 2,100m Prix du Jockey Club, which was reduced from 2,400m in 2005, is now held up by many to be the 'stallion-making race' – that is if one believes in such a concept. That may be item two on the agenda for the Newmarket pub debate next week.Is it not simply more the case that good stallions come from a variety of sources, and sometimes from left field? Again, this is a mere snapshot, but the current top ten stallions in Britain and Ireland include three 2,000 Guineas winners, two Derby winners (one of each of those being Sea The Stars, who also won the Arc), two Prix du Jockey Club winners, a July Cup winner, a treble Group 1-winning sprinter, a Prix Morny winner and a Middle Park winner.What we are lacking in there of course is a St Leger winner, because they really never get a chance any more, do they? Our friends in Japan appear to be the only breeding nation which still reveres a Leger winner, and the Japanese version, the Kikuka Sho, is even longer than ours at 3,000m.But, just as we could relearn a lot of other things from the Japanese that we seem to have forgotten – such as it not being polite to drop litter in the streets or bellow into mobile phones while on public transport – we could also reflect that among the winners of the Kikuka Sho are the successful stallions Deep Impact, Orfevre, Epiphaneia, and Kitasan Black. The latter, the sire of erstwhile Horse of the Year Equinox, currently shares the top spot as the most expensive stallion in Japan with his celebrated son. The 2019 Japanese St Leger winner World Premiere supplied this year's Japanese Derby winner Lovcen. Triple Crown winner Contrail followed World Premiere on the St Leger roll of honour and has been well patronised at stud, with his eldest runners now three. A stallion-making race? It's as good as any. The post Missing In Action: Where are the Middle-Distance Challengers? appeared first on TDN | Thoroughbred Daily News | Horse Racing News, Results and Video | Thoroughbred Breeding and Auctions.