In October of 1898, The New York Times reported on an American jockey named James Forman “Tod” Sloan who had begun riding his horse “crouched well forward on his mount’s neck.” The Times further noted that Sloan had "astonished the English turfmen and jockeys not only by his style of riding which is peculiar to him, but also by his great success.”

Now, more than a century after Sloan debuted the crouching technique, scientists have figured out how the now-standard riding posture boosts performance.

Before Sloan adopted his signature riding style, jockeys rode their horses upright.  But within 10 years his “peculiar” posture became the norm in the U.S. and riders around the world had begun to emulate it. In 1900, the Times attributed Sloan’s success in England—where the new technique had not yet caught on—to his “wit, light weight, and strength,” along with a good work ethic. A few observers, however, speculated that his riding style increased speed, perhaps by decreasing drag.

The new work, published today in the journal Science, reveals that the crouching posture does enhance speed, but not by reducing wind-resistance.

“We wanted to know why jockeys sit on the horse in a very strange, very uncomfortable-looking position,” says Thilo Pfau, an expert in biomechanics at the Royal Veterinary College of the University of London and lead author of the paper. Pfau and his team noticed that race times improved 5 to 7 percent in the 10-year transition to Sloan's style of jockeying, a far greater drop than occurred over the next century. To test whether this new posture could explain the improvement, the researchers determined the acceleration and displacement of both the horse and the jockey during running.

“Especially when it's running fast, a horse is bumping up and down—its feet are in the air and down again, landing on the ground in a certain order,” Pfau explains. “The horse is constantly changing its speed, and changing potential and kinetic energies.”

When seated upright, riders act much like sandbags, weighing down the horse and incurring increased mechanical and metabolic costs. But in the crouched “martini glass” position, a jockey can move relative to the horse and minimize this forward-backward and up-and-down movement. “The jockey doesn’t have to accelerate or decelerate compared to the world around him,” Pfau remarks. “It’s like sitting in a car when on a flat road, rolling along at constant speed.”

Some researchers have hypothesized that a jockey could in effect “drive” the horse faster than it could go on its own. Pfau believes this might be possible if the jockey is moving the right way at precisely the right time. "But we haven’t cracked that yet,” he says.

Top left photo of conventional riding posture by Vincent Orchard; bottom right photo of modern racing style courtesy of Tom Stanhope, Equine Action Images