Top traders using advanced strategies can achieve a situation where they will win around 90% of the time on each and every race.
Traders often trade more than one horse in a race as well increasing profits. When you consider there are races every 10-15 minutes or so every afternoon throughout the year you can instantly see the potential and why trading is a huge and growing business on betting exchanges.
Of course you can trade any sports event, not just horse racing, but anything you wish. The only prerequisite is that you know and understand how and why the odds move. To fail to do so would mean facing a loss-making situation for sure. Each event and the time at which you get involved and why radically changes the way you approach each market.