It is customary with fixed-odds gambling to know the odds at the time of the placement of the wager (the "live price"), although this category also includes wagers whose price is determined only when the race or game starts (the "starting prices"). It is ideal for a bookmaker to price up a book such that the net outcome will always be in his favour, i.e. the sum of the probabilities quoted for all possible outcomes will be in excess of 100%.

 The excess over 100% (or Overround) represents profit to the bookmaker in the event of a balanced book. In the more usual case of an imbalanced book, the bookmaker may have to pay out more winnings than what is staked, or he may earn more than mathematically expected. An imbalanced book may arise since there is no way for a bookmaker either to know the true probabilities for the outcome of competitions left to human effort or to predict the bets that will be attracted from others by fixed odds compiled on the basis of his own personal view and knowledge.

With the advent of Internet and bet exchange betting, the possibility of fixed-odds (Arbitrage - See below) actions and Dutch books against bookmakers and exchanges has expanded significantly. Betting exchanges in particular act like a stock exchange, allowing the odds to be set in the course of trading between individual bettors, usually leading to quoted odds that are reasonably close to the "true odds."

Asian Handicap (named so simply because of its Eastern origins) is a gambling term used to describe spread betting in soccer that has gained popularity over the years. The handicaps typically range from one quarter goal to several goals and can be described in terms of half or even quarter goals.

Most importantly, Asian Handicap betting reduces the possible number of outcomes from three (in traditional 1-X-2 wagering) to two by eliminating the draw outcome. This simplification delivers two betting options that each have a near 50% chance of success.

Asian Handicaps are both good and bad for bookmakers. On one hand, they help bookmakers minimize risk by facilitating trading with parity or balancing the amount of wagering on each side of the match. This enables bookmakers to take larger positions on major matches. On the other hand, Asian Handicap markets are typically low margin offerings that do not contribute as significantly to the gross win as other betting options.

Arbitrage

Betting arbitrage, surebets, sports arbitraging is a particular case of arbitrage arising on betting markets due to either bookmakers' different opinions on event outcomes or plain errors. By placing one bet per each outcome with different betting companies, the bettor can make a profit. As long as different Bookmakers are used for arbitrage betting the Bookmakers do not have a problem with this. Each Bookmaker will still make profit due to their calculations.

In the bettors' slang an arbitrage is often referred to as an arb; people who use arbitrage are called arbers. A typical arb is around 2%, often less, however 4%-5% are also normal and during some special events they might reach 20%.

Arbitrage Betting involves relatively large sums of money (stakes are bigger than in normal betting) while another variety, betting investment, means placing relatively small bets systematically on overvalued odds most of which will lose but some win thus making a profit.

The best way of generating profit, which has been established in Britain via sports arbitrage, consists of 'key men' employing others to place bets on their behalf, so as to avoid detection and increase accessibility to bookmakers. This allows the financiers or key arbers to stay at a computer to keep track of market movement.