Dosage Theory

Dosage is a theoretical means that mathematically measures racehorses are genetically biased to which abilities by dividing the racehorse's ability into two categories: speed and stamina. This theory evaluates horses based on the characteristics of their ancestors, which greatly influenced the ability of racehorses. This theory can be calculated from the stallions and mares that have had a significant genetic influence on modern thoroughbred racehorses.

The concept of Dosage was devised in the early 1900s by Vuillier, a retired French army officer who worked as a pedigree expert for legendary racehorse producer H. H. the Aga Khan. He applied complex mathematical formulas to quantify the genetic influence of the ancestral horses.

The Dosage theory was further refined by Franco Varola who is a famous Italian pedigree expert in the 1950s. He classified the chefs-de-race, which had a great genetic influence on modern thoroughbred racehorses, into five categories, and distinguish the genetic predisposition to their descendants.

In this classification, the stallions are classified into five types: Brilliant, Intermediate, Classic, Solid, and Professional. These are representing that the horses good at speed are in the left, and the horses good at stamina are in the right.