How is the point spread calculated?

If you’re new to sports betting and want to learn more about one of the most common types of wagers made by bettors, read below to learn what a point spread is and how it is calculated.

What is a point spread?

The point spread is one of the most popular types of bets at a sportsbook, particularly on football and basketball.

The point spread, or spread, is a number set by oddsmakers to even the playing field. It’s a way for the sportsbook to balance a matchup between two unequal teams by either giving points to the underdog or taking points away from the favorite in the final score.

In the NFL, where spread betting is the most common way people bet the sport, oddsmakers might set the point spread for a game between the New England Patriots and Tampa Bay Buccaneers at 3.5 points.

You will find a plus or minus sign listed in front of each team's point spread, depending on which team is the favorite (minus sign) and which is the underdog (plus sign).

If you bet the favorite, Tampa Bay, to win at -3.5, the Buccaneers will need to win the game by four points or more to cover the spread.

New England, the underdog at +3.5, will get 3.5 points added to their score by the sportsbook. In order to beat the spread, the Patriots need to win outright or lose by fewer than three points.

If the final score is Tampa Bay 31, New England 28, then New England covered the spread, since 28 plus 3.5 is greater than 31.

If the final score is Tampa Bay 35, New England 28, then Tampa Bay covered the spread, since 35 minus 3.5 is still greater than 28.

Often, a half-point is added to the point spread to avoid a push, or a tie between the bettor and the sportsbook. If the point spread was set at three, and Tampa Bay won by exactly three points, neither team covered the spread.

At TwinSpires Sports, you can also bet alternative point spreads. Simply click the “show list” button or use the slider to create your own custom bet or teaser, as seen in the example below, featuring a matchup between the Boston Celtics and Brooklyn Nets.

How sportsbooks set the point spread

To understand how a point spread is set, let's first look into the line listed next to a point spread on the odds board.

In the example above, with the Patriots and Buccaneers, both teams have -110 odds next to the point spread.

This is the most common betting line for a point spread. With -110 odds, bettors pay a 10% commission, also known as the juice or vigorish, to the sportsbook for taking their wager and, therefore, must risk $110 to win $100 on the point spread.

As bets are taken on a matchup throughout the week, sportsbooks often reduce the juice on one team so the line is, say, -105, which gives bettors the chance to win $100 by risking less money. Sportsbooks might also increase the juice if more action is going to a particular team, which forces bettors to risk more money to win $100 on the point spread. 

Sportsbooks raise or lower the juice — or increase or decrease the point spread — because their ultimate goal is to keep action on both sides balanced. 

When sportsbooks set the initial spread released to the public, they calculate the point spread using a variety of factors that are examined by both computer algorithms and human oddsmakers.

Among the factors are team records, key statistics, game location, whether a team plays well at home or away, public perception, and circumstances such as weather, injuries, or the result of previous games between the two teams in a matchup.

The farther apart teams appear based on these factors, the greater the point spread will be.

The spread can also shift based on any of these factors changing ahead of the game. For example, if a team's quarterback is ruled out midway through the week, the sportsbook will move the point spread accordingly to reflect the new imbalance in the matchup.

Why the point spread changes

When a point spread is perceived by bettors as accurate upon initial release, bettors will put equal action on both teams.

This is rarely the case, so sportsbooks often move the line to balance unequal early action.

Let's say the Memphis Grizzlies open as an 8.5-point underdog against the Utah Jazz, but a large number of bettors think Memphis will beat that spread.

If more money goes to Memphis early on, the sportsbook might adjust the line, either by raising the juice to -120 or greater, or by shifting the point spread to eight points.

As the spread becomes smaller, bettors eventually will find Utah a more attractive bet and begin placing more money on the Jazz, which balances out the action.  

Sharp money, or money wagered by professional bettors, will often shift the point spread, too.

If a sharp bettor places a large wager on one side of a matchup, it could move the point spread by as much as two points or more, so the sportsbook can attempt to even out the action and reduce its risk of a loss.

Now that you know more about the point spread, head to TwinSpires Sports and check out all the lines available on a variety of sports and matchups!