Here is an outline from SportsLine for understanding basic terms and concepts in the sports wagering industry:
How to read the point spread
Perhaps the most common question newcomers have when they see sportsbook odds is, "What do the numbers mean?"
While the plus and minus signs might look confusing at first, they are easily explained. Take the following listing you might see in a sportsbook:
457 Giants -3
In this example, the Giants are three-point favorites against the Cowboys. The spread is essentially a mathematical formula used to bridge the talent gap between teams and incentivize potential bettors into considering both sides.
The spread is a handicap that requires the favored team to win the game by an ascribed number of points in order for the bettor to win his wager on the team.
So if you wish to wager on the Giants in this game, you'd be giving up or "laying" three points with them. This means they would have to win by four or more in order to cover the spread and make your wager a winner.
Those who wish to support the Cowboys are betting on the underdog, and thus "taking" the points. Their tickets would read: Cowboys +3.
This means, in order for the wager to win, the Cowboys would need to lose the game by fewer than three points, or win it outright.
In the above example, the Giants winning the game by exactly three points would result in a push for bettors on both sides, and all wagers would be refunded.
The number to the direct left of the teams is called the "rotation" number. This is simply the universal record-keeping system for sportsbooks to track bets on each team. When you place a wager, you give the sportsbook ticket writer the rotation number of the team you are selecting instead of announcing the team name.
What is the over-under?
In addition to picking a side against the point spread, bettors have the option of wagering on the over-under or "total."
The total is mathematic formula created by oddsmakers to determine the approximate number of points that will be scored in the contest. The formula essentially boils down to taking the average of what both teams score and allow per contest, along with other mitigating factors such as the venue or key injuries.
In the above example, along with seeing the point spread on the betting menu, you will see a large number near the spread. It might look like this:
456 Cowboys 46
457 Giants -3
You'll see the spread is almost always delineated with the minus symbol and spread number corresponding directly to the favored team. The over-under or total is usually noted on the same line where the underdog is listed, but with a bit of separation from the team name so that it is not confused with the point spread.
In the above example, 46 points is the posted total between the Cowboys and Giants. If you wish to wager on the total, you would pick the rotation number of either team and inform the sportsbook writer that your intention is to bet the Over or Under only on the posted total.
What is the vigorish or "juice"?
If you have dabbled at all in the sports wagering industry, you've likely heard the terms juice, or vigorish, thrown around quite a bit.
If you've heard the terms but don't know what they mean, fret not. They might sound complicated on the surface, but they are relatively simple to explain.
In short, the vigorish is essentially a tax the sportsbooks charge per wager. Their role is the primary factor in turning a profit for bookmakers, and also a crucial factor for bettors to learn and respect.
The standard vigorish is 10 percent on each wager. In other words, you have to wager $110 in order to win $100 on your bets.
The manner in which this benefits the sportsbook is easy to explain. In the above example, let's assume Bettor A wagers $110 to win $100 on the Cowboys, while Bettor B wagers $110 to win $100 on the Giants. The sportsbook has taken $220 in wagers on this game, but will pay out $210 to the winner (the amount of the wager and the win combined). The $10 the sportsbook keeps is basically collected from the losing wager, and this is the most significant house edge it holds over the players.
Most experienced customers have factored the vigorish into their wagers, and plan their bankrolls accordingly in the interest of simple math and convenience. For example, a $100 bettor who wishes to make five wagers in a day will likely use $550 of his bankroll to finance five separate bets of $110 to win $100.
What is the difference between the money line and point spread?
In addition to wagering on either the point spread or total, sportsbook patrons almost always have the additional option of placing what is called a money-line wager.
A money-line wager simply removes the point spread from the equation, and notes that you are wagering on a specific team to win the game.
Money-line wagers are absent of the standard 10 percent vigorish -- $110 to win $100 – and instead simply involve a "price" on each team to win. The money-line price on each team is usually noted on the wagering menu to the far right of each team listed. A typical example would look like the following:
456 Cowboys 46 +150
457 Giants -3 -170
In this example, the Giants are not only three-point favorites against the spread, they are -170 favorites to win straight up on the money line. So if you were confident they would win but it might be close, you would pay $170 to win $100 on the Giants to win absent the point spread. To place this bet, you would tell the ticket writer you wish to place a wager on rotation number 457 and state the desired amount.
Conversely, money-line wagers on the underdog are popular because sportsbook customers can get a return that exceeds in the original wager. In our above example, the Cowboys are +150 underdogs to win the game outright.
If you wish to place this wager, you would be passing up the option of taking the points and winning the bet if the Cowboys lose by fewer than three. They must win in order for your bet to cash, but the incentive is the handsome payout. In this example, a $100 wager would win $150 for a total return of $250, instead of the standard point-spread bet of $110 to win $100 with a return of $210.
What is a parlay?
Parlays are popular wagers among bettors because of the appeal of potentially winning a good sum of money with a minimal investment. It's a widespread belief that parlays are mostly done by novice bettors, but experienced handicappers are known to play them as well.
Parlays involve the selection of two or more propositions on a single wager, and all of the teams must win for the bet to become a winner. For instance, if you pick five teams on a parlay and four cover the spread, the bet is a loser.
Sportsbooks welcome parlays because of their significant house edge. For instance, the true odds on a two-team parlay are 4-to-1, but most betting outlets pay 2.6-to-1 on the wager. The true odds on a three-led parlay are 9-to-1, though the standard payout is 6-to-1.
Even so, the potential for winning more than the initial investment have proven to be an irresistible lure for most sports bettors, regardless of experience level. If you put $100 on a two-team parlay and win, your profit will be $260 for a total return of $360.
What is a teaser?
Teasers are a popular variation of standard point-spread betting, as they give the customer an advantage by increasing the point value for their selected team.
For example, the six-point teaser is an extremely popular bet in professional football, where a high percentage of spread outcomes fall very close to the sportsbook's numbers. To combat this uncertainty, teasers provide a discount on the spread.
Let's say you believe two seven-point favorites will win the game outright but you are unsure whether they can cover the sizable touchdown spread. Using a six-point teaser would reduce each team to a -1 favorite, meaning they only have to win by two in order to cover the reduced spread.
Because of this advantage, teasers pay much lower odds than a parlay, but many handicappers still find them profitable. In the above example, a two-team teaser on professional football is likely to carry a price of -120 (bet $120 to win $100), or steeper depending on the wagering outlet.