Spread Betting Explained – How Does it Work and What Does -2, -3.5, -7 Mean?
What is a Point Spread?
A point spread is a type of bet ultimately based on the margin of victory of a game or match. It is a function of sports betting used to make every matchup one of nearly (or exactly) equal probability by setting the margin of victory by the favored team.
Very rarely do sportsbooks see games as 50-50 coin flips, or as commonly referred to in bettors’ language: pick em’s. When the matchup is not one of equal probability, it would not be profitable for sportsbooks to take bets on the predicted winner (favorite) and the predicted loser (underdog) at the same price.
For example, during Week 14 of the 2021 NFL season, the 8-4 Tennessee Titans played the 2-10 Jacksonville Jaguars. If the sportsbooks had been taking bets on each side to win the game at the same exact odds, it would be a no-brainer for the bettor to place a wager on the vastly superior Titans. Common sense and analytics alike say the Titans will win that game well over half of the time, so it would be an extremely profitable bet if the teams were priced equally.
How Does Spread Betting Work?
Spread betting is bet used when sports bettors are wary of betting on a moneyline, or rather a team to win the game outright.
Say, for example, a team is a huge favorite and the moneyline is above -200. That’s typically not worth risking, for the payout won’t be very large. Instead, betting said favorite to cover the spread, or win by a determined margin, can net you typically around -110 odds.
On the contrary, spread betting is very useful when betting on underdogs. Sometimes, an underdog line might be too risky for them to win outright, but if bettors feel the game may be close, the spread is a great option.
Bettors can typically also bet custom spreads. For example, if the spread is set at -6, but a bettor feels the favorite team is going to win by much more than that, they can bet -10 for increased odds.
What Does -2, -3.5 and -7 Mean in Point Spreads?
First off, any spread that’s a – is a favorite. A + means that team is bet is an underdog. Therefore, -2 means that a team must win by more than two points in order to cover the spread. If they win by exactly two points, the bet would push and the stake would be returned with no winnings.
Similarly, -3.5 means the team must win by more than four. When there is a half point, there is no pushing bets – it either wins or loses. Bettors must pay attention to these spreads based on which sport they’re wagering on. For example, 3.5 in NFL betting means that a team winning by a field goal would be a loss.
-7 is another important prop line in football betting. Your team winning by exactly seven points means they push, whereas over would be a win and under would be a loss.
Examples of Point Spreads
To even out the wagers the sportsbooks receive on the game, oddsmakers set a point spread favoring Tennessee to win by 8.5 points. The spread can and will vary slightly across different sportsbooks, but 8.5 was the general consensus. That means when a point spread wager on the Titans is placed, Tennessee would have to win the game by 9 points or more, i.e. to cover the 8.5 point spread.
On the other hand, if a bet is placed on Jacksonville, the wager wins if the Jaguars were to win the game or lose by less than 8.5 points.
Tennessee ended up winning the game by 20 points (20-0), so point spread wagers on the Titans cashed, while bettors who took the Jaguars point spread lost.
How to Read Point Spreads
When a point spread is listed on a sportsbook, it is accompanied by a “+” or a “-” sign. The “-” sign means that the team is the favorite, so Tennessee was listed as “-8.5.” Jacksonville, as the underdog, was listed at “+8.5.”
The logical way to think about this format is to imagine that Tennessee is beginning the game with -8.5 points. If that were the case, according to the oddsmakers, the Titans and Jaguars would have a near-equal win probability.
While the chances of the bet hitting may be about equal in the eyes of the sportsbook, the general odds for a point spread are still -110 on both sides of the bet, meaning a bettor must risk $110 to win $100. That extra risk is called the vig, and is how sportsbooks ensure they make money.
However, sometimes the book doesn’t view the spread as exactly equal so will have the prices at something like -115/-105. Generally speaking, the two numbers add up to -220. If not, that probably means the book is taking more or less vig than is standard. As always, please use the OddsJam’s Odds pages to easily find which sportsbook has the best line and price for your bet.
How are Point Spreads Made and Calculated?
Sportsbooks calculate point spreads using a combination of data-driven computer formulas and human input. Statistical power ratings (such as KenPom for college basketball) are taken into account, as are injuries, travel, matchup history, and of course home field advantage. For example, the home team generally sees a two to three point edge in the NFL. So if the Titans and Jaguars had been playing on a neutral field, the spread would have been about six. If it was at Jacksonville, it would have been about three points instead of the 8.5 at Tennessee. This can vary depending on the home team and circumstances. When the Seahawks were at their peak playing in front of the 12th man, bookmakers would give more of an advantage than in the past few years when the Chargers would play games in front of largely visiting fans in a soccer stadium.
Like all betting odds, point spreads can and will move based upon a number of different factors. For example, the Titans/Jaguars spread opened at Tennessee -9 but by kickoff on December 12th it was 8.5 at most books. This was a small line movement, but sometimes lines can move several points in one direction or the other due to action the books take in from bettors. If a substantial amount of money comes in on one side of the line (called a steam move), the sportsbooks will have to adjust the line to entice bettors to take the other side. Sportsbooks always want to have as close to equal amounts of money being bet on each side as possible so they are not at risk of taking a huge loss. Another factor that can change the line is sharp bettors. If one sharp is well known for winning consistently and bets a large sum on one side, that alone could compel the sportsbook to move the line.
Since point spreads are volatile, the timing of a bet can be crucial. If a bettor sees an opening line that they predict will move significantly, they want to get in early before it shifts. Once it changes in the predicted direction, not only does that bettor have a positive EV bet, but it also opens up opportunities to middle the bet or place an arbitrage bet.
When to Bet Point Spreads
A bettor should bet the point spread when they think that the team will cover the spread. If someone was thinking about betting on Tennessee but thought it would be a close one possession game, it would not be advisable to place a bet on the point spread. However, if the person thought the Titans would really dominate Jacksonville, betting the -8.5 point spread would make a lot more sense than taking a risk-heavy moneyline at a much steeper price.
How to Bet the Spread
When betting a point spread, it’s always a good idea to look around at various books to try and get the highest value bet possible. For example, DraftKings may have had the line at -8, while FanDuel was at -8.5 and Caesars at -9. A person interested in betting on the Titans would have DraftKings as their best option, since eight points is less for a favorite to cover than nine.
Meanwhile, someone betting on Jacksonville should go to Caesars and take advantage of the nine point cushion on the underdog.
As always, be aware of the price of the wager as well.
Point spreads in Baseball and Hockey
Baseball and hockey are a little bit different because of how few runs and goals are scored in each game, as opposed to football and basketball. Many games in these two sports end up being decided by just one run, or one goal.
What is a Run Line?
In baseball, the point spread becomes the “run line.” In the vast majority of Major League Baseball games, the run line is set at -1.5 for the favorite and +1.5 for the underdog. On a very rare occasion, perhaps where an ace like Jacob deGrom is starting against a struggling pitcher on a bad team, the run line can creep up to -2.5 but for the most part, MLB teams are evenly matched enough (and playing a fairly unpredictable sport like baseball) where the line will always be -1.5.
In the final game of the 2021 MLB season, Game 6 of the World Series, the Astros were -125 to win the game (moneyline) while the Braves were +115. The run line was Astros -1.5 at a +150 price, and Atlanta was +1.5 at -175.
What is a Puck Line?
Likewise in hockey, the “puck line” is set at -1.5 for the favorite and +1.5 for the underdog. Whenever betting the puck line, always remember the strong possibility of an empty net goal in the final couple minutes that could flip the outcome of the bet.
Since these two sports have far less scoring, it is uncommon for the run or puck lines to be of equal probability and have an equal price. Here is an example of a puck line:
When Anaheim visited St. Louis on December 12th, St. Louis was a slight favorite on the moneyline (just to win the game) at -130, while the Ducks were +110. Since St. Louis was the favorite, their puck line was -1.5, and Anaheims’ was +1.5. However, the oddsmakers saw this as a tight game, so a bettor on the St Louis puck line at -1.5 got a price of +170, while a bettor who thought Anaheim would win the game or just lose by a single goal took the Ducks +1.5 at a price of -200.
Factors to Consider When Betting Run Lines and Puck Lines
While MLB doesn’t have goaltenders being pulled to increase the probability of an outcome decided by over one goal/run, it does have extra innings where any number of runs can be scored. In hockey, overtime is sudden death so a -1.5 puck line bet is never going to win in NHL overtime.
Learn also, how does line shopping works!