Betting on sporting events has long been the most popular form of spread betting. Whilst most bets the casino offers to players have a built in house edge, betting on the spread offers an opportunity for the astute gambler. When a casino accepts a spread bet, it gives the player the odds of 10 to 11, or -110. That means that for every 11 dollars the player wagers, the player will win 10, slightly lower than an even money bet. If team A is playing team B, the casino is not concerned with who wins the game; they are only concerned with taking an equal amount of money of both sides. For example, if one player takes team A and the other takes team B and each wager $110 to win $100, it doesn’t matter what team wins; the casino makes money. They take $100 of the $110 from the losing bet and pay the winner, keeping the extra $10 for themselves. This is the house edge. The goal of the casino is to set a line that encourages an equal amount of action on both sides, thereby guaranteeing a profit. This also explains how money can be made by the astute gambler. If casinos set lines to encourage an equal amount of money on both sides, it sets them based on the public perception of the team, not necessarily the real strength of the teams. Many things can affect public perception, which moves the line away from what the real line should be. This gap between the Vegas line, the real line, and differences between other sports books betting lines and spreads is where value can be found.
For beginning sports gamblers, moneylines (sometimes called money lines or American odds) can be confusing. Unlike point spreads, which are concerned with who wins and by how much, a moneyline is solely dependent upon who wins. Moneylines are used most commonly in low-scoring games like baseball or hockey, but they may also be used in boxing and other sports.
If a team favored by six points wins by exactly six points, the outcome is considered a "push" and the bettors get their money back, minus the bookmaker's commission. To reduce the number of pushes, oddsmakers often set spreads with half-points. So if the Cowboys are 3 1/2- or 3.5-point favorites over the Giants, they must prevail by four or more points to pay winning bets.
The team that has the minus sign, which is the favorite, has points deducted from its final score, while the dog, with the plus sign, has points added. The favorite must beat the spread, which means they have to win by more than the negative number to pay off. The underdog pays off in two instances—if they win outright or if they lose by less than the spread.