How the point spread works - When two teams meet on the playing field or on the basketball court, one team is typically better than the other or in a more favorable position because of factors like playing at home. If all you had to do were pick the winning team in a game, everybody would simply wager on the best team or the home team in a even matchup and bypass all the lines and collect their winnings at a high rate.
Several additional states such as Louisiana, Connecticut, Mississippi, Maryland, Massachusetts, Missouri, California, South Carolina, Iowa, Illinois, Kansas, Kentucky, Indiana, Michigan, Minnesota, Oklahoma, Ohio, New York, and West Virginia, began drafting bills to legalize sports betting soon after New Jersey and Delaware. Pennsylvania, Rhode Island, and West Virginia were able to pass legislation legalizing sports betting within their states.
Before I go on, let me clarify some terminology. Despite it being probably the most popular way to bet, there is no particular term for a bet against the spread. Many people call this a "straight bet." However, this term can also be used, and is printed on tickets for, money line bets, total bets, and any other bet involving just one game. For purposes of this page, I call such bets a "point spread" bet, and invite the rest of the world to adopt this terminology.
Often big games will have "proposition" bets on things not directly related to the final score of the game. These are usually abbreviated to "prop" bets. For example, in football whether or not the first score will be a touchdown. In baseball whether a run will be scored in the first inning. In hockey/soccer, whether anybody will score a hat trick. The odds on these are expressed like point spread bets. For example, as I write this the Golden Nugget has the following proposition bet on Super Bowl 49:
You can also bet straight winners and losers -- with no point spreads involved -- with money line wagers. When there is a minus number you bet that amount to win $100 in profit. When there is a plus number, that is your winning profit for every $100 wagered. So if the Cowboys have a money line of -250, you would have to bet $250 on them to win $100 in profit on any Dallas victory. If the Giants had a money line of +150, you would win $150 in profit with a winning $100 bet. If a money line is posted as even, you would win a $100 profit on a $100 winning bet.
The concept of betting on totals, or Over/Under (O/U), is quite simplistic. The bettor wagers on whether the TOTAL points scored in a game will fall over or under a pre-determined number set by the sportsbook. Much like the point spread, game totals can be swayed by public opinion. The example below, from the SI Archive, shows the opening totals line for Superbowl XLV:
Say the Bears are a six-point favorite over the Lions and the total is 42. To bet the Bears, you must "lay the points," meaning they must win by seven or more to cover and give you the win. Betting the underdog Lions, you are "taking" six points, and they can lose by five or fewer, or win the game outright, and you have a winning bet. If the Bears win by exactly six, both sides "push" and all bets are returned. It's also a push if the final score equals 42, otherwise the over or under will win.
There’s only one DFS style game in Las Vegas casinos today. US Fantasy Sports can be found in about 14 casinos and it continues to grow. In this type of football betting, you wager on which player will rank 1st, 2nd or 3rd from a pool of players in specific positions. The wagering style is similar to horse racing where you can wager on win, place, and show. You can also make exacta and trifecta wagers. There’s also an option to place a $1 wager and pick winners from all pools to win $1,000,000.
Major League Baseball (MLB) Commissioner Rob Manfred has also advocated the league changing its stance on sports betting, with both Manfred and Silver noting that the scale of illegal sports betting makes opposition to betting meaningless. He also stated a willingness to "try to shape" any future legislation at federal level. This was noted as a marked contrast to former Commissioner of the MLB Bud Selig, with Manfred going beyond tacit approval and stating, "There is this buzz out there in terms of people feeling that there may be an opportunity here for additional legalized sports betting."
In this example the Jets are listed as four-point favorites (-4) over the Bills and the 49ers are three-point underdogs (+3) against the Seahawks. So, if you bet $110 on the favored Jets, they must defeat the Bills by more than four points in order to win $100. If you bet $110 on the underdog 49ers you will win $100 if they win outright or lose by less than the three-point spread. If the final score happens to end up exactly on the number it's a tie, or 'push,' and you get your money back.
The most important thing you can teach yourself early on is: "Just because the books assign one side to be the favorite (even large, -200 or -300, favorites), does not mean that they will win." We have all seen favorites get upset, and it is important to avoid the temptation of finding comfort in the fact that the lines makers put one team as a favorite.
In addition to the spread bet, a very common "side bet" on an event is the total (commonly called the over/under or O/U) bet. This is a bet on the total number of points scored by both teams. Suppose team A is playing team B and the total is set at 44.5 points. If the final score is team A 24, team B 17, the total is 41 and bettors who took the under will win. If the final score is team A 30, team B 31, the total is 61 and bettors who took the over will win. The total is popular because it allows gamblers to bet on their overall perception of the game (e.g., a high-scoring offensive show or a defensive battle) without needing to pick the actual winner.
For those that live outside the United States, this may look even more strange since -110 is in American odds format. In Decimal odds, which is common in Europe, -110 translates to 1.91 odds. I'm not going to dive into Decimal odds (or other formats) since this article is about American odds, but the Decimal system is pretty straightforward. The odds listed represent a bettor's total return for a winning wager as you simply multiply the odds by the amount you wish to risk. If someone risks $100 at 1.91 odds and win, they receive $91 plus their initial $100 risked ($91 + $100 = $191).
Sportsbooks also offer wagering on the total or Over/Under – the cumulative number of points scored by both teams in a game. You can bet on if the final score will go either Over or Under that set total. For example, in a game pitting Team A vs. Team B, the total is 48. A wager on Over wins if the total points scored exceeds 48, and a wager on Under wins if the total points scored falls below 48. If the total lands on 48, it’s a push and wagers are refunded.
When you see a moneyline value associated with the point spread, it is the percentage amount you must pay in order to book the bet. Also known as the juice or vig, if you see -11.5 (-115), it means you have to bet $115 to win $100 — a 15 percent commission for the sportsbook. The underdog may see a value such as +11.5 (+105), which means you’ll have to bet $100 to win $105 if your team successfully covers the spread.