Dosage and Synthetic Surfaces

Although it is early in the game and many of the issues associated with the introduction of synthetic racing surfaces to Thoroughbred racing remain unresolved, we have taken a first look at their impact on Dosage.

The venues included in the study are Arlington Park, Del Mar, Keeneland, Turfway Park, Woodbine, Santa Anita, Golden Gate Fields and Presque Isle Downs, all of which had synthetic surfaces installed beginning in late 2006.

The methodology involves a comparison of Dosage results obtained in open stakes races on the synthetic surfaces at those tracks with the results obtained over the same timeframe in open stakes races on dirt at all other tracks.

The first task was to establish whether the basic Dosage model in which Dosage figures correlate with winning distance hold up on the new surfaces.  The following charts plot the DI vs distance and CD vs distance for the winners of about 120 open stakes races on the synthetic surfaces.

Despite the relatively small sample size, the model holds up well.  We can easily observe from the trend lines, for both the DI and CD, a decrease in the relevant Dosage figure with an increase in winning distance.  Therefore, we may conclude that the switch from traditional dirt racing has no observable impact on the genetic preference of runners for distance.

Next, we directly compared the data obtained from sprints (races shorter than a mile) and routes (races at one mile or longer) on dirt and synthetic surface tracks.  The results are displayed in the following table.

The data reveal negligible differences between the Dosage figures of winners at similar distances on the two types of surface.  The correlation is shown in the following chart.