Indeed interesting, and it does not surprise me that a human can beat a animal carrying a heavy load (a human) in an endurance event given we are hairless sweaty mammals optimised for endurance rather than speed. Adding a proportional burden for humans (maybe 10kg) would give horses a huge advantage.<p>It seems the race is also long-term optimised for humans to win. There are a lot more human competitors (> 10:1 ratio). The prize fund increased by 1000 pounds per year until a human won, no doubt attracting faster and faster athletes in increasing numbers.<p>The course has also been varied making year on year comparisons difficult.