What Are Spreads in Betting?

One of the more interesting aspects of sports betting is that, although some consider it to be a form of gambling, it actually isn’t. The spread in betting is the difference in the point-spread between the favored team and the underdog team. The spread indicates the amount of points the sportsbook thinks the game will come down to. In other words, it’s the amount of credit (or debit) the bookmaker is willing to risk on the game. The spread is usually expressed as a percentage, but it can also be expressed as the number of points separating the two teams. For example, if the spread is 3.5, this would mean that the point-spread is 35 points in favor of the home team. Let’s take a look at how this works in practice.

How Do Bookmakers Calculate Spreads?

The process for calculating a spread is fairly straightforward. After the points for the game have been determined (usually by the point-spread equation, which depends on the number of points scored in each quarter and how many minutes have been played in the game), the sportsbook will use the following formula to determine the point-spread for the game:

  • The amount of credit (or debit)
  • The amount of credit (or debit)
  • The amount of credit (or debit)
  • The points scored in each quarter
  • The quarter the game is in (i.e., first, second, or third quarter)
  • How many minutes have been played in the game so far (i.e., 1st quarter, 2nd quarter, or 3rd quarter)

For example, if you were to bet $100 on the Arizona Cardinals (CAR) to win the Super Bowl, and the over/under is set at 51.5 points, the total bet amounts to $105 ($100 + $5 for the over/under). Before the game even starts, you’ll need to place a bet of $5 on the Cardinals to win the Super Bowl. If they do in fact win the Super Bowl, then your total profit (i.e., the amount you made after taking your original bet, in this case, $105) would be $100 ($105 minus $5). As long as the Cardinals win the Super Bowl, you’ll win your bet. However, if they lose the Super Bowl, then you lose your $100.

Keep in mind that many books will round down any winning bets to the nearest half-point, so if you’re taking a risk and the Cardinals do in fact win the Super Bowl, you might lose a little money. Still, it’s probably wise to bet on the underdogs in football (i.e., the teams that are typically considered to be worse than their record might indicate). After all, as we know from past history, sometimes underdogs don’t always play fair, and sometimes they even win the big one.

When Do Bookmakers Set The Spread?

There’s no set rule as to when a sportsbook will set the spread for a game. It really depends on a variety of circumstances. For instance, if a team is playing a game in a couple of hours and the spread hasn’t been set yet, it might make sense to guess that the bookmakers are waiting until closer to the scheduled playing time to set the point-spread. Similarly, if a team is close to half-time and the score is close to balanced, it might make sense to guess that the bookmakers would like to lock in a point-spread as soon as possible because there’s less of a chance that the half-time score will dramatically change the final result of the game. Of course, sometimes the spread will be set well in advance of the game even taking place. Usually this is the case with close games or games that have a lot of importance to one or both of the teams (i.e., conference championship games, divisional fights, etc.).

Why Are Spreads Set So Widely?

If you’re unfamiliar, the spread in betting is actually measured from a ‘neutral’ point-spread. That is, if you’re betting on a team from the Atlantic Coast, then the spread is usually set to favor North teams. This is because most people in the U.S. are more familiar with the scores of North football teams (i.e., the Bears, the Packers, and the Giants), and so a bookmaker wants to give the impression that these teams are more dominant than they actually are (i.e., the point-spread is frequently wider than it needs to be, for the fear of an upset). This is also why most spread bets are placed on games that are closer to even than one might think, as too many upsets have happened in history, particularly in the early years of the National Football League.

How Does The Point-Spread Influence My Chances Of Winning?

The point-spread is important because it influences your chances of winning. For example, if you bet $100 on the Arizona Cardinals to win the Super Bowl and the point-spread is 0.5, this means that your chances of winning are actually 50% (half + half = half). In other words, there’s a 50% chance that your Cardinals will cover the spread and win the Super Bowl (50% = (1 – 0.5) + 1). Similarly, if the point-spread is 4, which is a fairly extreme point-spread, this means that your Cardinals are almost assured of winning. In that case, setting the spread at 6 would be foolish, as the odds of your Cardinals winning would dramatically decrease to 33.3% (4 + 6 = 10, and 10 ÷ 2 = 5, or 50% – 66.7%). In essence, setting the spread too low will dramatically decrease your chances of winning and vice versa.

What Other Factors Influence The Spread?

Besides the team that you’re betting on and the point-spread, a number of other factors influence the final result of a football game. These include the quality of the teams, time of year, and the weather. With that in mind, let’s take a quick look at some of the variables that could drastically change the result of an otherwise close game:

  • The teams
  • Time of year
  • Weather
  • Head-to-head matchups
  • Individual players

In the table below, you’ll see the four categories above (teams, time of year, weather, and head-to-head matchups), along with an overall ‘overall favorability’ score for each team. This overall favorability score is based on a variety of factors, including each team’s recent performance, whether or not that team is playing at a prestigious venue (i.e., ‘ESPN Factor’), win-loss records, and so on. Naturally, some books will give greater weight to some categories over others, but in general, this score serves as a good indicator of which teams are the most likely to win, and it does so based on a variety of factors.

Keep in mind that these scores don’t always align with the perceived ‘quality’ of the teams. As we just mentioned, you’ll frequently see books put the New York Yankees at a ‘neutral’ (-150) rating due to their extensive roster of stars and legendary seasons (they’ve won 27 World Series titles). However, even diehard baseball fans might have a hard time arguing that the Boston Red Sox are anything but a notch below the Bronx Bombers (they’ve won 26 World Series titles themselves).

As for the weather, if you live in a relatively humid area with lots of rain, then it will be tough for teams from the South (and vice versa). Similarly, if the game is played in snow, then this will make it difficult to execute any kind of defensive scheme, regardless of how talented your team’s athletes might be. This is why you don’t see many indoor sports played in cold weather, especially not football.

How Is The Spread Used In Practice?

One of the more interesting things about the spread in betting is how it’s actually used in practice. As we mentioned above, the point-spread is usually set rather wide, for the fear of an upset. However, this doesn’t mean that it’s always the same way. Sometimes, depending on circumstances, the line-maker will decide to set the point-spread very narrowly (i.e., closer to zero). This is done to increase the odds that their own team will win, since a narrower spread makes it easier for them to cover (i.e., if their team wins, then their winnings will be relatively high).