Racehorses that stay in the pack longest before breaking for the final sprint have the best chance of earning prize money, scientists said yesterday.

By tucking in cleverly behind the leaders, the horse uses “aerodynamic drafting” to its advantage, they said.

By coasting along behind the front horses, which are battling wind resistance, it saves energy for the final dash.

Jockeys, like long-distance runners and Formula 1 racing drivers, have always known about drafting, also called “covering up” in the racehorse business. But this is the first time its importance has been pinpointed in data and measured, the paper’s authors say. The work could one day develop into a tool for racing fans, they believe.

“When measured over the entire race, the average speed of a horse goes up the more time it spends tucked in behind other horses,” Andrew Spence of the Structure and Motion Laboratory at Britain’s Royal Veterinary College said.

“If you convert that difference in speed into how the horse finishes, it can amount to a gain of three to four places.”

Mr Spence and colleagues had access to a statistical gold mine: data garnered by a British company, TurfTrax Racing, which places a radio-frequency chip in the horse’s saddle, enabling the animal’s position to be triangulated at any point in a race.

The team had access to more than 4,500 races staged at 10 British racecourses from 2005 to 2007. On average, horse races are decided in the last 500 metres, give or take 200 metres depending on whether the race is longer or shorter, the study said.

At this break point, the speed of competitors diverges as the horses muster the strength to the finishing line. But contrary to popular perception, the final sprint sees a slowdown rather than an acceleration, for the horses are tiring.