United States vs. European Dosage Figures

In order to address the universality of Dosage methodology, we have undertaken a study to compare Dosage figures for U.S. racing with those for European racing.  An initial comparison has been made between U.S. Grade 1 race winners from 1990 through 2000 and the winners of 38 European Group races over the same time frame.  The European races, with the average Dosage figures, are listed at the end of this page.

The summary statistics in the following table indicate that the average distance of European Group races is significantly longer than the average distance of Grade 1 races in the U.S. (9.95 furlongs vs. 9.11 furlongs).  Not unexpectedly, and consistent with Dosage theory, the European figures show a lower average DI (1.92 vs. 2.85) and CD (0.42 vs. 0.65).  The required increased stamina for European racing is also reflected in smaller Brilliant and Intermediate contributions to the DP, along with larger Classic, Solid and Professional contributions.  The Europeans have a marginally greater number of points in their DP.  

The following graphs display the relationship between winners' average DI and the average race distance in both the U.S. and Europe.  The red trend lines represent the best fit of the data using linear regression.  As anticipated, and once again consistent with theory, the trend on both continents is the same, with the DI decreasing as the distance of the races increases.  The flatter slope seen for the European races suggests a lower sensitivity of pedigree to distance, although as pointed out by Dosage expert Steve Miller, the observation may be due to the differences in the range over which races are run within each venue.  Additionally, small changes in the average figures in the relatively few races run at the extremes of the distance spectrum could easily alter the slope as well.  Nevertheless, it is clear that the principles of Dosage apply equally well on both sides of the Atlantic.

We find an identical pattern in the following graphs displaying a similar relationship between average CD and average distance.