When people buy a broodmare, their intention surely isn’t to breed a winner of a Class 6 handicap on the all-weather. No, the hope must be that the mare will prove capable of producing a stakes winner, the ultimate dream being a Group 1 prize or a Classic.

But what is the most reliable route to the higher echelons? Fortunately for the longevity of the sport, there are numerous different ways of fulfilling the Group 1 dream, as was explained in a fascinating study conducted by The Blood-Horse in 2010. Using the American Jockey Club’s database, the study was based on the records of 65,196 mares which produced a foal in North America in 1998, 1999 or 2000. These 65,196 mares were responsible for a total of 407,812 foals.

Of course there are some major differences between American and European racing, but the similarities are still large enough for the American statistics to have some bearing on what happens on this side of the Atlantic.

All is not lost, though, if budgetary restraints place Group-winning fillies well out of your reach

The study divided the mares into nine categories, ranging from unraced to Grade 1 winners. They provided an eye-opening reality check for anyone contemplating the purchase of a filly foal or yearling. No fewer than 11,529 of the 65,196 mares – nearly 18% – had never made it to the races, while another 12,132 – nearly 19% – never made it to the winner’s enclosure.

The largest category concerned ordinary winners with no black type, these 30,141 representing 46% of the sample. Add these together and you have nearly 83%, which of course means that only 17% had managed to achieve that elusive black type. Only 1,447 – a miserly 2.2% – had achieved the status of Graded winner and the 462 Grade 1 winners equated to a mere 0.7%, which illustrates the enormity of the task facing any young filly.

The statistics highlighted why there is so much demand from breeders for Group/Grade 1-winning mares. The 462 Grade 1 winners achieved the highest percentage of Graded winners to foals (5.77%) and the highest percentage of Grade 1 winners (2.44%). The next most successful, in terms of percentages, were the Grade 2 winners, followed by the Grade 3 winners.

This appears to be a ringing endorsement of the belief that success breeds success. Unfortunately the situation isn’t quite as straightforward as you might think (but what is in the world of horse breeding?). These Graded winners usually enjoy the advantage of having access to the very best stallions, a privilege often denied their less accomplished counterparts.

Of course some of the lesser lights on the racecourse will eventually earn access to the higher-priced stallions by producing Group winners, but the statistics also showed that a young mare’s best chances of producing a stakes winner or Graded winner usually rested with her first five or six foals.

In the American study, fillies and mares which were placed at Group/Graded level outperformed stakes winners as broodmares, producing 3.56% Graded/Group winners, compared to 1.95% from the stakes-winning mares. I wonder here whether this is influenced by the sheer size of the American industry, with stakes races being contested everywhere from Arapahoe Park in Colorado to Zia Park in New Mexico. The chances are that many of these stakes races do not represent the same quality normally found in European Listed races, so I would have more faith in the potential of a European Listed winner (with the possible exception of Italian winners of recent years).

I thought it would make an interesting exercise to look at the 2014 Group 1 winners in Europe to see whether they conformed to the American data. Unfortunately I don’t have comparable data for Europe to enable me to quote percentages, but these 2014 Group 1 races seem to support the American data.

There were 85 Group 1 races contested in Britain, France, Ireland, Germany and Italy, and they were won by a total of 65 individual horses. Seven of the 65 were produced by Group 1-winning mares and it is significant that they included arguably the two most accomplished three-year-olds. Four-time Group 1 winner Kingman is out of the Poule d’Essai des Pouliches winner Zenda, whereas the three-time Group 1 winner Australia is out of Ouija Board, a Group 1 winner in England, Ireland, the USA and Hong Kong. For the record, the other Group 1 winners with a Group 1-winning dam were Miss France (1,000 Guineas), the dual winner Integral, Tapestry, Full Mast and Found.

Another six, including the Classic winners Kingston Hill and Marvellous, were out of mares which scored at Group 2 or Group 3 levels. Altogether, the winners of 19 of the 85 Group 1 races were produced by Group winners. That’s over 22%, which is remarkable when I remind you that only 2.2% of the American mares in The Blood-Horse study were Graded winners.

All is not lost, though, if budgetary restraints place Group-winning fillies well out of your reach. The winners of 17 of the Group 1 races – 20% – were won by horses out of mares which were either unraced or failed to win. In the American study unraced mares outperformed non-winning mares in producing either a stakes winner or a Graded winner.

In Europe the unraced mares were responsible for ten winners of 13 Group 1 races, whereas the mares which raced but failed to win had only four winners. It is worth taking a look at the quality of the unraced mares. Most of them are well connected, some of them very much so. For example, the Deutsches Derby winner Sea The Moon has a dam who is a sister to two winners of the Deutsches Derby and one of the Preis der Diana. Then there’s Fillies’ Mile winner Together Forever, a half-sister to the Group 1 winner Lord Shanakill. Their dam Green Room is one of three daughters of Chain Fern to have produced a Group 1 winner.

And how about Dievotchka, dam of the Prix Rothschild winner Esoterique? This unraced daughter of Dancing Brave had previously produced three Group 2 winners, plus a pair of Group-placed Listed winners.

Then there’s Prix Maurice de Gheest winner Garswood and the Prix Morny winner The Wow Signal, both of whom have Group-placed Listed winners as their second dams. It was a three-parts-sister to the July Cup winner Owington who produced the Phoenix Stakes winner Dick Whittington, while a sister to the smart sprinter Tropical Star is the dam of Prix de l’Abbaye winner Move In Time.

It therefore seems advisable to look for a mare with a solid pedigree, though Cirrus Des Aigles reminds us that almost anything is possible. This multiple Group 1 winner is out of an unraced mare whose dam and second dam failed to produce any black-type performers.