Sports betting is one of the oldest and most simple forms of wagering. Wagering on sporting contests goes back almost indefinitely into history. Broadly speaking, there are three main approaches to winning at this form of gambling.
This depends on constructing a statistical model of a team or an individual’s chances in a contest. For example, in a game of American football, you might weigh various factors in the assessment of a team’s chances. You might add 1 point if the team is in good form, 3 if they are playing at home, 2 if they are without a star player and so on. You measure their score against the opponents and determine the chances of either winning.
Note this is exactly what bookies do. However, the formula the bookies use is quite crude and may not reflect the true odds (see below).
It is possible to design a superior model to the bookies. If you can design a model which has a statistically significant degree of success over the bookmaker’s model, then you will be able to identify situations in which the bookmaker’s assessment of the odds is incorrect and place winning wagers consistently.
Sometimes the bookmakers will have wildly differing opinions about a game. You can take advantage of this by betting with the bookmaker who is out of line with the consensus and offers over-generous odds. An extreme example of this is a method known as arbitrage: this is when the bookmaker’s lines overlap, so an astute bettor could bet with both and profit whatever happens. NOTE: In practice, this is very difficult to do, as such opportunities are quickly exploited. If the odds change before you have “closed” both sides of the wager you render yourself open to substantial liability.
Sometimes bettors do not bet in accordance with a rational assessment of their team’s chances. To give the most obvious example of this, in international soccer matches the home team is always heavily backed for patriotic reasons. The resulting odds are almost always poor, while the foreign team usually has quite good odds. The bookmakers must do this in order to balance their books and get a sure profit.