Odds are multipliers that express the probability of a particular outcome in sports. To turn the odds into a probability in percent, you should divide a hundred by decimal odds. So, if a bookmaker gives 1.75 odds, the probability of such outcome will be 100/1.75 = 57 percent. Sometimes, a change in odds is instigated by external factors, independent on the probability of the outcome. Such an external factor could be a market overload, when a lot of players bet on the particular outcome. The odds usually are of three types: decimal, fractional and American..