Often horse races are won just by the tip of a nose or a body length or two. Factors such as the jockey's ability, nutrition, the track surface, and training all play a role in the outcome. But the mindset of a horse is the most important of all. When it comes down to it, what's going on in that horse's head often makes him a good runner. When we make a horse run on the treadmill in the lab, he'll often paw at the tread, like he's saying, 'hey, I want to go and have some fun. It tells that he loves running. So much of what makes a horse a good racer is up in the head.