Standard sports wagers fall into one of four categories: straight bets, accumulators/parlays, proposition bets and future bets. Straight bets can be further broken down into money line wagers, over/under wagers and point spread wagers. This page will focus on point spread wagers.
Some sports require teams with very different levels of success to play each other, either because of scheduling or through an elimination process. If bookmakers were to try to make money lines on these sports, some games or matches would simply become unattractive betting propositions. To avoid this problem, bookmakers use point spreads to even teams up and create viable wagering opportunities. Point spreads are typically used on sports like the NFL, college football and basketball, Aussie Rules Football and the NBA.
The point spread lines will be stated as follows: the favorite will have a minus number and the underdog will have the exact opposite number. For instance, the favorite in an NFL game might be listed at -4.5. In that case, the underdog would be +4.5. After the point spread is posted, the bookmaker will allocate an associated money line of approximately -110 on each side.
Why? The bookmaker does not want a vested interest in either side of a game or match. They set the point spread where they feel they’ll get equal action on both sides. If the betting public favors one side over the other, they can move the point spread up or down until they get the desired effect. Here’s what balance betting would look like from the online bookmaker’s perspective.
If the betting public wagered $110,000 to win $100,000 on both the favorite and the underdog, the bookmaker collects a total of $220,000 but only has to pay out $210,000 to the winning side. They make $10,000 profit with no vested interest in the game. Theoretically, the bookmaker could allow up to 9% more to be bet on one side over the other before they have exposure. That’s the point they might decide to move the point spread.
Example: How Point Spread Works
In the 2018 Super Bowl, the New England Patriots were favored by 4.5 points over the Philadelphia Eagles. The Eagles won the game outright as underdogs, but let’s assume New England won by 4, 35-31. To determine the winner based on the point spread, the bettors who wagered on New England would take New England’s final score, subtract the 4.5 and see if New England still has a higher score. In this case, they didn’t, therefore, the New England side loses. Philadelphia bettors would add 4.5 to Philadelphia’s score to get the same result. If the game ends in a tie after the point spread is applied, the game is a push and all straight bets are refunded while accumulators or parlays are reduced one level.