This is because bookmakers are in business to make a profit, so they effectively charge a commission for taking wagers. This commission is known as the vig, short for vigorish, and it's one of the ways that bookmakers stay profitable. They don't charge it just for points spreads and totals either, as it's built into the odds for every wager that they offer.
According to an article in The Times dated 10 April 2009, approximately 30,000 spread bet accounts were opened in the previous year, and that the largest study of gambling in the UK on behalf of the Gambling Commission found that serious problems developed in almost 15% of spread betters compared to 1% of other gambling. A report from Cass Business School found that only 1 in 5 gamblers ends up a winner. As noted in the report, this corresponds to the same ratio of successful gamblers in regular trading. Evidence from spread betting firms themselves actually put this closer to being 1 in 10 traders as being profitable, with a high number of clients suffering from the volatility that is supposed to be one of the benefits of spread betting.
Above, you can see several numbers to the right of both teams. These all represent the different lines that are available on the San Francisco vs. Los Angeles game. The first set of numbers for both teams is the point spread, the second set is the moneyline, and the third set is the over/under (a.k.a. totals). We'll explain each of these lines more in-depth below.
The moneyline works differently. With this type of wager whichever team wins outright pays off. There is no spread. How does the line work? The favorite is listed with a minus sign and a number. That number is the amount of cash that must be bet in order to win $100. The underdog is posted with a plus sign in front of a number. The number is how much a sports bettor wins on a $100 wager.
The general purpose of spread betting is to create an active market for both sides of a binary wager, even if the outcome of an event may appear prima facie to be biased towards one side or the other. In a sporting event a strong team may be matched up against a historically weaker team; almost every game has a favorite and an underdog. If the wager is simply "Will the favorite win?", more bets are likely to be made for the favorite, possibly to such an extent that there would be very few betters willing to take the underdog.
Wagering on the NFL revolves around the point spread in which one team is designated the favorite and the other team is called the underdog. The NFL point spread sets a specific number of points that the favorite must win by in order for a person betting that particular team to win their wager. Lets use an example from last week's NFL slate to demonstrate the art of NFL point spreads. This past weekend the New England Patriots played the Seattle Seahawks. The Patriots were four point favorites in that game. So in your local newspaper, you might have seen something similar to this illustration.
One of the first rules of gambling is that nothing is ever certain. There's one thing that's almost certain though; you will make mistakes as a beginner. This is nothing to worry about, and in fact making mistakes is an important part of the learning process. That doesn't mean you need to make unnecessary ones though. There are a few mistakes that are routinely made by beginners, and it pays to be aware of these.
In Asian betting markets, other frequently used formats for expressing odds include Hong Kong, Malaysian, and Indonesian-style odds formats. Odds are also quite often expressed in terms of implied probability, which corresponds to the probability with which the event in question would need to occur for the bet to be a break-even proposition (on the average).
Sometimes with NFL odds you’ll see a spread posted as a whole number. Decimals or fractions are usually utilized to ensure there won’t be a tie. If in our example the spread was reset to 10 with the Colts favored and they win by 10, then the game is considered to be a tie, which in betting terms is called a push. If there is a push all bets are off and the sportsbooks return all wagers back to the bettors.
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.
So the sportsbooks and bookies created a point spread to make both teams equally attractive in the eyes of bettors. Carolina was installed as a 6-point favorite, which is commonly written as Carolina -6. Denver, the underdog, is commonly written as Denver +6. In other words, Denver would be credited with whatever points they actually scored — plus six. If you bet the favorite, the Panthers would have to win by 7 points or more for you to win your wager. And remember, the Panthers are favored by 6 points, so we have to subtract 6 points from their final score for betting purposes.
For example, in NFL wagering you’ll have a pool of 12-14 quarterbacks, running backs, etc. and you can choose who will have the most fantasy points, 2nd most fantasy points, 3rd most fantasy points. Each player starts the week with certain odds that change as money wagered on different players. Your payout is based on the closing odds like parimutuel horse wagering.
Because the spread is intended to create an equal number of wagers on either side, the implied probability is 50% for both sides of the wager. To profit, the bookmaker must pay one side (or both sides) less than this notional amount. In practice, spreads may be perceived as slightly favoring one side, and bookmakers often revise their odds to manage their event risk.
Apply the money line. It's easiest to think of money lines in relation to $100. A minus sign means you have to bet that much money in order to win $100; a plus sign means that a $100 bet will return that much money. If you bet on Chicago at -110, you'll have to wager $110 in order to get back $100 (plus your original $110). If you bet on Detroit at +145, then a $100 bet will give you $145 (plus your original $100).
Total: Also called the over/under, it is a number set by the sportsbooks that proposes a number of points that will be scored in the game by both teams combined. Then, fans predict whether there will be more points or less points than the Â‘total.Â’ If you bet the under 41.5, you are hoping for a tough defensive battle with lots of running game. Pick the over, and presumably you feel this will be a high-scoring game. In short, you are predicting whether the combined total score will be more than (over) or less than (under) the total.