The jumps at these things are taller than the average human, so even a rider as experienced as 65-year-old Ian Millar can't always will a horse over top without incident.
So it was in the medal round of the Olympic individual equestrian jumping event, where Millar's mount Star Power clipped the second obstacle in a triple jump combination to squelch any hopes Canada's Summer Games Ironman had of winning an individual medal.
"I felt needed a little more power in his body, and when I did that I ended up getting length, that's what put me into the front rail," Millar said after a final round that saw him hit two fences - only one rider, gold medalist Steve Guerdat of Switzerland and his horse Nino des Buissonnets, managed two penalty-free rounds in the final.
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So Millar goes home with a ninth-place finish, and dreams of attending his 11th Olympics in 2016 in Rio de Janeiro.
"If Star Power wants to go, which is very likely because he should be the right age, he can't go without me," he said, " so therefore I'll go."
Earlier in the day Canada's Eric Lamaze, the gold medalist from the 2008 Games, fell out of contention when his horse, Derly Chin de Muze, knocked down two fences and stepped into a water jump during the initial phase of the final round.
In the second-place jump-off, the Netherlands' Gerco Schroder won silver - aboard the appropriately named London - and Ireland's Cian O'Connor won bronze atop Blue Loyd 12.