While live in-game wagering and fantasy-style prop betting have gained ground in recent years, its still the good old football point spread that dominates each weekend. Why? Its traditionally the most fun way to bet football and its simple and easy to understand.

But how is the point spread set and what do all the numbers on a football betting odds screen mean? NationalFootballPost.com takes you through the basics of the football point spread.

Known as the line or the spread, it is sometimes (wrongly) thought of as what the oddsmaker thinks will be the margin of victory by one team. In reality, the point spread is set by betting experts, tested against real professional bettors and then refined based on what number they believe will encourage the same number of people to bet on the underdog as the favorite. Check the example below in an all-New York game.

 NY Giants -9 NY Jets +9

The negative value -9 indicates the Giants are favored by 9 points. The positive value (+9) indicates the Jets are underdogs of 9 points. To place a bet on the favored Giants means they must win by at least 10 points to cover the spread. The underdog Jets can lose by eight points and still cover the spread. If the score is 21-10 for the Giants, they won by 11 points, which is more than nine, so they have successfully covered the spread and you have successfully won your bet. If the score is 30-24 for the Giants, they have won the game by six points, which is less than nine points so they failed to cover the spread and you have lost your bet (even though the Giants won the game).

Current football odds boards will usually include the â€˜juiceâ€™ component of a point spread as well, which is traditionally -110. This is the standard commission charged by a sportsbook for booking the bet. It means you pay a 10 % fee to make your wager. You get that \$10 back if you win (along with your profit), but you lose it if you lose. Basically, you wager \$110 to make a \$100 profit. Or for smaller bettor, you wager \$11 to win a \$10 profit.

A typical game line would look like this:

 NY Giants -9 -110 NY Jets +9 -110

### How is the point spread set?

There is a little bit of art, a little bit of science and a little bit of math that goes into setting the point spread each week. And if the oddsmaker is being honest with you, heâ€™ll tell you its a little bit of guesswork too.

As soon as Saturday NCAA games and Sunday NFL games are over, you can usually find point spreads for next weekendâ€™s games. These are â€˜opening linesâ€™ and are posted for a) early birds who want to get action right away for the following week and b) oddsmakers to get an early reading on how the betting public will react to the odds.

### Do pro bettors help set the line?

In the old days and during the heyday of early online sportsbooks, a linesmaker would meet with his team and come up with a point spread. They would then offer that point spread to some of their regular bettors and allow them to place a \$5,000 wager on the favorite or underdog. Depending on how those regulars bet the game, the oddsmaker would revise their initial point spread and release it to the public.

### Why does the NFL or college football point spread change during the week?

If the opening line in the Cowboys-Eagles games is -7 Dallas and it moves quickly to -5, that tells you that a lot of early bettors jumped on the Eagles at +7. The oddsmakers â€“ who are trying to get equal amount of betting dollars on each team â€“ moves the line downwards in hopes of encouraging more Dallas betting. By Tuesday or Wednesday, enough betting has happened that the line has settled, maybe at -6, maybe lower at -4.5. After that, its reports from practices, the weekly league injury update and maybe some weather considerations that move the line up or down.

And then on gameday, the public comes in looking to make their last-minute bets on their favorite teams so a bunch of money comes in and this can move the line as well. So, a line that opens on Monday morning at -7 might get bet down to -3 by kickoff. Conversely, it could get bet up to -10 if bettors really love the Cowboys and the Eagles have a bunch of injuries.

So you might get a better point spread early in the week or you might get a better line later in the week. You need to watch the football line moves and figure out if you should bet early or bet late.