What is Doseage All About?
The dosage index system calculates the likelihood of a thoroughbred race horse winning a race, over any given distance, based on the pedigree of the horse. This has been a breeding and handicapping system, first developed in France, used for decades but did not really become well known or popularly used until 1981 when a columnist from the Daily Racing Form published a new version, developed by Steven A. Roman Ph.D. which had supporting statistical data. Dr Roman published a book of this version in 2002 called Dosage: Pedigree & Performance.
The index looks at four generations of sires of a horse and notes if any of these are `masters of the breed` (chef-de-race). This title will be given to those sires that have progeny who have excelled in their racing careers and over what distance. The different distances are called Brilliant (shortest races and therefore horses bred for speed), Intermediate, Classic, Solid and Professional (longest races and therefore horses bred for stamina). If the progeny of one of these sires excel in more than one distance these can only be a maximum of 2 categories apart or they are discounted.
When the sires of a racing horse are studied and a name is on the list of masters, then points are given. 1st generation = 16 points (split 8 + 8 if necessary), 2nd generation = 8 points, 3rd generation = 4 points and 4th generation = 2 points. From here there are mathematical calculations made, resulting in a single digit number which is the dosage index. Full details of those calculations are available on the web or in the above book.
There are some issues with the system that have raised questions and doubts, particularly with studies done with winners of the Kentucky Derby, who have not fitted the expected profile. The reasons that have been given for this varies. Horses are often sent abroad to countries where the races better suit them. The bloodlines of the dams are not taken into consideration. This system does not take into account the condition of the ground. The list of masters is still limited. A lot of horses do not have four generations of sires all of which are masters and therefore the ability of their progeny is an unknown factor and so throws all calculations to the wind. It has been noted that in steeplechase, although the distance is long and normally that means you would be looking for a `Professional` background, the speed and agility of the `Brilliant` background gives them some advantage over the fences.
There are undoubtedly some aspects of this system that work and can be taken seriously. Possibly as more and more information is gathered and more names added to databases for analysis, the results can be refined and become more reliable. For now it maybe that the dosage index is just one more bit of information, along with other racing tips, to added into the mix which points to a possible winner.