You Know Who Has to Deal with Rio’s Toughest Event? Horses

Of all the grueling events at the Summer Olympics–the marathon, the crash-prone cycling road race, open-water distance swimming–maybe none is as technically demanding as the cross-country portion of equestrian “eventing.” On Monday, the course decimated the field during the event: Only three riders out of 65 completed the course within the time allowed, and 18 didn’t finish at all, making it one of the toughest courses in modern eventing history.

At the Olympics, cross-country courses are typically designed to be “just right” on the Goldilocks scale: difficult enough for the world’s top riders, but not so challenging as to be impossible for those who are less prepared. Because it’s a sport controlled by elite riders from a handful of countries, the competitive gap can be huge–and when the course is so hard that it shakes up even the most skilled horse-and-rider pairs, the rest of the field doesn’t stand a chance. Cross-country is the most dangerous discipline at the Games: If something goes awry in how well the riders are matched to the course, it’s not an issue of national pride, it’s an issue of safety.

One of the best things about the Olympics for viewers is the phenomenon of relatively unpolished athletes competing against world champions (see: the Jamaican bobsled team, Eddie “the Eagle” Edwards, Eric the Eel). But when it comes to horses, there’s even more of a gap. A regional tradition of excellent breeding, the quality of training available in a country, and the money a country is willing to put into backing their team all have huge bearing on how well a rider may perform. And that gap can actually be hazardous in cross-country, which forgoes the well-groomed arena sand of eventing’s other two phases–show jumping and dressage–for an outdoor course, where the turf is less stable and more weather-sensitive.