Probability is the chance of a particular event occurring. For example, in tossing a coin, there are two possible outcomes: heads or tails. If the price offered on an event occurring is equal to its probability, then the price can be deemed fair (in the above example, Evens either event).In attempting to predict the outcome of football matches, an approximation of probability can only be made by looking at historical evidence, along with any other influential factors. For extended events, unknown factors (e.g. weather) can affect the chance of a particular event occurring. `Fair` prices are educated guesses of the expected probability of an event occurring, since exact calculations are impossible. Bookmakers form an opinion on the probability of an event occurring and price it accordingly. There is a potential for profit if they are wrong, assuming, of course, that the punter notices the error.

Fixed Odds

`Fixed odds` betting has its origins in the fixed prizes offered by late nineteenth-century newspapers for forecasting match outcomes. Bookmakers still offer `fixed odds.` The term applies more to high street betting offices, who publish a long list of football matches and their odds for the coming weekend several days in advance. This is an expensive process and cannot be repeated if mistakes are made or if the bookmaker needs to alter a price. Once the list goes to print, the betting odds become fixed. An Internet bookmaker has more flexibility and can change a price to manage his projected liability. However, even for high profile matches, with a large turnover, the odds available for the standard home/draw/away market do not change by more than about 10%.

Rating Systems & Value Bets

For football betting, determining such probabilities involves the analysis of previous events. Some punters use a numerical approach to historical analysis, known as ratings systems.

The traditional approach to beating the bookmaker has been through forecasting and prediction techniques in an attempt to reveal errors by the bookmaker. The punter approaches an event in exactly the same manner as the bookmaker, namely estimating the probability of a particular result and giving it a numerical value. This leads to both bookmaker and punter calculating their own price for a particular outcome. If the bookmaker`s price is greater than that of the punter, this constitutes a value bet.

Popular Betting Events

English football is without doubt the most significant betting medium. Since its inception in 1992, betting on the Football Premiership has increased in every season. The domestic cup competitions, predominantly the F.A. Cup, also attract vast numbers of online wagers. As a result of television coverage, top European players in the Champions` League have become household names. The Champions` League is also a source of many online football bets, even when there is no British team involved. The same can be said of Euro 2008. Despite all the `home` nations failing to qualify, online betting interest has been lively. World Cup 2010 has also seen some online betting action, even at this early stage.