You should already know that the Eagles are the favorite to win and that you should expect less than even money on a correct pick here. You should also know that the Falcons are the favorite, and you should expect better than even money on a correct pick here. Having this in mind every time before you start your calculations will protect you from making a mistake and calculating the completely wrong direction.
"Winning Margin" (aka Result Betting) is where it is possible to bet on the final result of a game or event and select the correct ‘band’ of points between the winning team and losing team. For example, if you think the Patriots will win, but the game will be close, pick the New England Patriots 1-6 Points Winning Margin (where the Patriots winning by 1, 2, 3, 4, 5, or 6 points results in a winning selection).
Here in this point spread example for the NFL, the Falcons are playing the Panthers. Atlanta has been set as a three-point favorite on the betting line. That means that for Atlanta to cover the spread that has been set, they will need to win by at least four points. And for Carolina to cover the point spread, they can do so with a loss by two points or less, or obviously a win straight up. If the Falcons win by exactly three points, the bet would result in a push with no payouts.
To counteract this, the sportsbook decides by how many points they think the Mavericks will win. In this case, they think the Mavericks should win by 4 ½ points. On the same token, they think the Celtics should lose the game by 4 ½ points. 4 ½ points is known as the line or the spread. If you bet on the Mavericks with a spread bet, they have to win by MORE than 4 ½ points for you to win your bet. If they win by 5 points, you win. If they win by 20 points, you win. If they win by 4 points, you lose.
When a betting line is listed, it will contain the moneyline and spread information. If there are two teams and there is a spread of +6 and -6, betting on the favorite, which is the – spread, the score must be greater than the underdog’s score to win. For example. The score between the Patriots and Bengals is 20 to 10. So, 20-4 is 14, which is greater than the 10 points earned by the underdog, so the bet will win.
One important assumption is that to be credited with a win, either team only needs to win by the minimum of the rules of the game, without regard to the margin of victory. This implies that teams in a winning position will not necessarily try to extend their margin—and more importantly, each team is only playing to win rather than to beat the point spread. This assumption does not necessarily hold in all situations. For example, at the end of a season, the total points scored by a team can affect future events such as playoff seeding and positioning for the amateur draft, and teams may "run up" the score in such situations. In virtually all sports, players and other on-field contributors are forbidden from being involved in sports betting and thus have no incentive to consider the point spread during play; any attempt to manipulate the outcome of a game for gambling purposes would be considered match fixing, and the penalty is typically a lifetime banishment from the sport, such is the lack of tolerance for gambling in sport.
This highlights a notable advantage of the moneyline wager. You get to control, to some extent, the risk versus reward. For example, you might be quite certain that the Cardinals are going to win this game, but not convinced that they're going to cover the spread. So a moneyline wager is the safe option. There's less money to be made, but less chance of losing. On the other hand, you might think that the Packers are going to cause an upset. Rather than betting on them to cover the spread, you can bet on them to win outright. There's less chance of winning such a wager, but the potential returns are much greater.
Futures betting also is offered on the major events in horse racing, such as the Kentucky Derby and Breeders' Cup. In horse racing futures, if your horse does not start the race due to injury or any other reason, you lose the bet -- there are no refunds. On the other hand, the odds on your horse racing futures bet also are "locked in," regardless of the horse's odds on race day.
That was all before Charles McNeil, a math teacher from Chicago, invented the concept of the point spread. An avid gambler, McNeil created what he called “wholesaling odds” and started his own bookmaking operation in the 1940s. He started out offering this new style of betting on football, but his business model grew to include basketball. McNeil changed the way sports betting was done, and his legacy lives on today in what we now call the point spread.