Many people watch horse racing videos in order to refine their techniques in either racing or gambling. Some watch the videos in order to observe which horses sufferered inteference or were disadvantaged in some way during a race and may be able to improve at their next start with more luck on their side.
Some jockeys also watch horse racing videos in order to strategize their races. They try to improve their techniques in order to gain the advantage in a race. You see, horse racing is not just about speed, it is also about finesse. A jockey needs to be able to plan out his or her moves while riding at breakneck speeds.
Improving these techniques, of course, will help jockeys win. By watching horse racing videos, they can observe their old mistakes and make improvements. They are also able to observe their opponents and study their techniques. Through this, they can find the best way to finish ahead of their rivals.