How Accurate is the Point Spread at a Sportsbook?

A sportsbook is a website or a brick-and-mortar building that accepts bets on various sporting events. In some states, sportsbooks are legally licensed and offer a variety of betting options. However, starting one requires careful planning and a deep understanding of regulatory requirements and market trends. Additionally, operators must be prepared to invest a significant amount of capital into their operations.

The simplest way to measure how accurately the point spreads proposed by sportsbooks capture the median margin of victory is to compute the expected profit (on a unit bet) for matches with a given point spread so. To do this, we stratified a large sample of regular season National Football League matches and analyzed the distribution of their margin of victory across the different points spreads.

We then compared this distribution to the distribution of the estimated median margin of victory across all points spreads. We found that the expected profit was substantially lower when the point spread was closer to the true median. This indicates that if the point spread is too far away from the median, it will be impossible to make a positive profit on every wager placed. However, if the point spread is within 2.4 percentiles of the true median, then consistently wagering on the side with the higher probability will yield a positive expected profit. This result underscores the importance of ensuring that point spreads are accurate. This can be accomplished by analyzing the distribution of the median margin of victory across all points spreads or by using a more advanced statistical model to estimate the true probability distribution.