Analyzing the Dosage Strategy for Horse Races

Pedigrees form an important but often overlooked part of the horse racing betting equation, with most punters preferring to concentrate on the numbers in the form book because they cannot wrap their heads around the world of bloodlines.

However, thanks to an American academic with a deep love of horse racing, pedigrees and how they are likely to impact upon performance, particularly in the highest quality contests, are easier to comprehend than ever before.

Dosage is a mathematical analysis of the strengths in a horse’s pedigree based upon the location of certain outstanding stallions in its family.

How the Theory Developed

Building on the work of French pioneer Jean-Joseph Vullier, who first wrote on the subject in 1902, and Italian breeding expert Franco Varola, Steve Roman created a new version of what Vullier and Varola had termed dosage, with the American chemist’s approach receiving widespread attention when it appeared in the Daily Racing Form newspaper in 1981.

Roman’s Concept
Roman took the ideas of Vullier and Varola and fused them, incorporating both quantitative and qualitative components in the hope of providing additional insights. To establish greater utility, Roman chose to use more four-generation pedigrees instead of the extended pedigrees used previously. Roman reintroduced Vuillier’s approximation of a genetic effect by halving the influence of any chef-de-race – an influential sire on a specially compiled list – in each successive earlier generation. And Roman established a statistical method for evaluating the results.

The sires of note are the chefs-de-race and, as of January 2013, there are 218 in Roman’s list. The chefs-de-race are the stallions that have had a major influence on the breed over the last 100 years. Depending upon the generation in which a sire appears, it contributes a certain number of points to the horse. First generation is worth 16 points, second generation is worth eight points, third generation is worth four points and fourth generation is worth two points.

Five Categories of Dosage

Roman has assigned chefs-de-race to one or more of five categories:

  • Brilliant
  • Intermediate
  • Classic
  • Solid
  • Professional

These five categories represent the spectrum of speed (brilliant) to stamina (professional). Therefore, a brilliant chef-de-race is one that produces sprinters and a professional chef-de-race is one that produces stayers. A classic chef-de-race is one that produces middle-distance horses. It really is that straightforward. The only minor complication is that Roman has placed some chefs-de-race in more than one category.

For example: Sadler’s Wells is a classic/solid chef-de-race points that Sadler’s Wells generates are split between those two categories.

Armed with four-generation pedigrees – easy to lay one’s hands on these days because of the wealth of free resources online – it does not take long to compile dosage profiles for the full field of a race. And from those dosage profiles one can calculate both the dosage index, for which Roman is most famous, and the centre of distribution quickly.

The Frankel Dosage

Let us take a look at Frankel’s dosage profile to see how Roman’s approach works in practice. Frankel is the world’s highest rated horse of all time, winning 14 races in a row before retiring unbeaten in October 2012. Frankel’s dosage profile is 5-2-15-7-1 based on Roman’s chefs-de-race list.

To arrive at Frankel’s dosage index, one must take the sum of the first two figures and half of the third and divide it by the sum of the last two figures and half of the third.

By the Numbers
– So Frankel’s dosage index is (5 + 2 + 7.5) / (7 + 1 + 7.5) = 0.94

– The centre of distribution formula is [(brilliant x 2) + intermediate] – [solid + (professional x 2)] / total points

– Therefore, Frankel’s centre of distribution is [(5 x 2) + 2] – [7 + (1 x 2)] / 30 = +0.10

Frankel’s dosage index and centre of distribution suggests that he was a freak to win the English 2,000 Guineas and other one-mile races because his dosage index was very low compared to most eight-furlong champions. There was much talk about how Frankel would handle the step up to 10 furlongs but his dosage index and centre of distribution suggested that he would probably improve over the extra distance, with both numbers being those associated with a classic performer.

Roman’s website not only contains the latest chefs-de-race list but also historical data pertaining to many of the world’s top races. Use Roman’s dosage approach to assess pedigrees quickly and easily. One will be surprised as to how many good- and bad-value horses it can highlight.