This page is intended to be a layman's guide to the mathematics of betting . The principles apply equally well to any event from a horserace to the Election to Provostship of Trinity College Dublin . Live betting shows for today's Irish and British horse racing can be found on the WWW .
Bookmakers quote prices as odds ratios.
The potential return is known when the bet is struck. For example, a dividend of 4 for a 1 stake means that the punter makes 3 profit. The potential return depends on everyone else's bets and is not known with certainty until after the event. Mathematicians , statisticians and economists think of prices as probabilities. For bookmaker betting, the overround has been found to depend on the number of runners .