Below is an example of how prices are set based on the nature of the event. Let’s take two horse races, same venue, same type of race.
Race 1: Big well-known race, well-known names competing, high stakes spread across the various player. Bookmakers can then compile odds easily and without much adjustment.
Race2: Small race, with unknown participants. Is unlikely to generate as many stakes, so betting a high amount on 1 horse causes more headaches for the Bookmakers than race 1. To secure the Bookmaker’s margin, the odds per horse will go down, to have a higher ‘over-round’ percentage overall, so this acts as a buffer for the Bookmaker.