 If you had to bet on a horserace without knowing anything about any of the horses, which one would you bet on? It probably wouldn’t matter to you: each horse is as likely to win as the others, so you’d be indifferent between the available wagers. If there are 3 horses in the race, each has a 1/3 chance of winning; if there are 5, each has a 1/5 chance; etc. This kind of reasoning is common and is often attributed to the Principle of  Indifference:[5]