The horse race is the most ancient of sports, and its basic concept has not changed: A contest between two or more horses whose speed or stamina determines the winner. It has evolved into a huge enterprise involving large fields of runners, sophisticated electronic monitoring equipment and enormous sums of money, but the premise remains the same. On a racetrack, humans perched on a horse’s back compel the beast with a whip to run at breakneck speed that is not in its nature, and many horses are injured or killed during a race.
It was a perfect day for a horse race, and the field lined up in the clubhouse turn of the track under dappled sunlight. War of Will, the 2014 Preakness champion, took an early lead, followed by Mongolian Groom and McKinzie. A crowd of six-and-a-half thousand humans switched from cheering to shrieking as the horses accelerated into the last stretch.
On the backstretch, the horses swung their heads in unison, breathing hard and exhaling clouds of dust. Then came a surge that sent the pack scattering, as horses of all sizes and shapes ran in every direction, each jockey looking for a place to position himself or herself to make an advantageous move.
In a race, a horse’s pedigree is determined by its sire (father) and dam (mother). A horse’s age is also an important factor in the horse race, with younger horses carrying more weight than older horses. Some races are handicapped, with the racing secretary assigning weights to entrants that are designed to equalize their winning chances. In addition, sex allowances are often given, with fillies having to carry less weight than males.
A team led by mathematician Sabina Aftalion, from the Ecole Polytechnique Fédérale de Lausanne in Switzerland, set out to study how to improve the performance of horses during a race. They looked at timed historical data from elite flat horse races on various surfaces, as well as comparable human data from similarly elite athletic events. They also considered a number of race tactics, including whether the winning horse was held up, sped up or held back in the beginning, as well as its finishing position.
Their analysis found that horses whose starting positions are farther back perform worse at the end of the race, while horses who have a strong start perform better. They also found that a horse’s ability to use powerful aerobic muscles that consume oxygen, as well as anaerobic ones that do not require oxygen but build up waste products, is a key determinant of its finishing speed.
The findings suggest that jockeys should try to maximize a horse’s aerobic capacity by starting them off slowly and pushing them to use the fuel they have available. Aftalion and her colleagues believe their model will enable trainers to plug in parameters for each horse, such as its unique aerobic capacity, to generate custom racing strategies ranging from pacing recommendations to ideal racing distances.
