Price Over Round
If you don't know how the betting shops etc make money from offering gambling markets to punters, it is via the "over round". Prices are offered on a horserace, these odds have a mathematical advantage built in when added together. Over a long period of gambling, almost all bettors lose. The over round, (vig or vogorish) is the culprit.
Over Round Related♠ 1x2 Betting Over Round Explanation
♠ The Over-Round - Never A 100% Fit