How jockeys help horses to run faster
1900: A change in riding style is associated with faster racing times
In the early 1900's, a major change in riding style occurred when American jockeys (starting with Tod Sloan in 1897 and then many more) started to compete very successfully in British racing. Their riding style style involved the use of shorter stirrups and the now familiar crouched ("Martini glass") posture on the horse.
As an apparent result of this change, there was a 5-7% reduction in the times taken to run races. This was a very significant drop: in the following almost 100 years of racing at the Epsom Derby the time only dropped by a further 2%.
The Structure & Motion Laboratory research team, based at the Royal Veterinary College in Hertfordshire, has now used modern technology to examine the science behind this phenomenon. They have now shown the way in which, using this "Martini glass" style, an experienced jockey can actively assist a horse to run faster.
A galloping horse doesn't run smoothly
A load carried by a horse, whether a conventionally seated rider or a sandbag, makes more work for the animal; this explains why handicapping horses — the practice of attaching weights to saddlecloths — reduces their racing speed. In previous research, when the SML team analysed the movement of a galloping horse, it became apparent that the horse — and thus also any rigidly attached ‘inert’ load carried by the horse — is not moving at constant speed but is accelerating and decelerating forwards and backwards and up and down throughout every single stride. This often quite violent movement will be only too familiar to anyone learning to ride.
How does the jockey help?
The team speculated that as a result of the crouched ‘Martini glass’ riding style an experienced jockey could avoid the acceleration and deceleration that the horse has to apply to an inert load — so that the jockey maintains a comparatively constant speed throughout each stride, thus making less work for the horse.
Showing how the jockey smoothes the movement
Using a number of racing jockeys and horses, they attached lightweight inertial sensors to the saddle and to the jockey. This allowed them to quantify the movement of both horse and jockey independently and then to compare the two. The results showed that in the forwards and backwards direction (horse 10 cm, jockey 2 cm) and up and down direction (horse 15 cm, jockey 6 cm), the movement of the jockey was much less than that of the horse. This has scientifically demonstrated that a skilled jockey can lessen the work the horse has to do, resulting in an increase in speed.
What about aerodynamic drag?
The team did speculate that the crouched riding style could also improve performance by providing less aerodynamic drag. However they calculated that this could only result in a reduction of 2% in racing times whereas the actual change (5 to 7%) was much greater. In addition to this, photos of historic race finishes in the early 1900's would not suggest a dramatic reduction in drag.
Watch the movies
A short movie in which scientist Andrew Spence describes the work:
Interviews with Andrew Spence and Alan Wilson for American television:
Read the paper
Pfau, T., Spence, A., Starke, S., Ferrari, M. and Wilson, A.M. (2009). Modern riding style improves horse racing times. Science. 325 no 5938, p 289. DOI: 10.1126/science.1174605
- This work was carried out by Dr Thilo Pfau, Dr Andrew Spence, Dr Sandra Starke, Dr Marta Ferrari and Professor Alan Wilson
- Thanks to the British Racing School for their help in conducting this research.
- Black & white still photos reproduced from "The Derby Stakes" by V Orchard.
- Inertial sensors manufactured by Xsens Technologies BV