The one who galloped furthest

Two herds of very rare breed of wild Thoroughbreds roam freely about in their beuatiful wild land. Both herds have colts, the colts are raised hpily together in the wild, only to be stolen from their herds. And put on the race track. The two go to different stables, living far away from eachother, but both training to become the super horse of the century. Who will be super horse.