My journey to creating this blog actually began over a decade ago, after reading this article in Sports Illustrated. To summarize, the article basically explains what goes into setting lines in Vegas, and the skills and knowledge required to be a quality oddsmaker. What I was surprised to discover when reading the article was that the oddsmakers chronicled within were not necessarily concerned with making accurate predictions about the outcome of games; rather, their main aim was to set a line that would ensure even action on both sides of a given competition. This makes sense from a financial standpoint: If there is equal action on both teams involved in a given game, the casino will simply collect their commission (or juice/vig), and not have to risk exposure to losses based on the outcome (Sidenote: There is some research that suggests bookies actually do not set a line to ensure equal action on both sides, and instead attempt to set up a scenario in which one team will have both more action and a less likely chance to cover). This was interesting to me, in that it meant bookies would essentially have to predict how the betting public would allocate their money in order to determine the correct line; it meant that bookies are just as much social psychologists and sociologists as they are sports experts.
In order to explain a little more deeply what I’m talking about, consider the following scenario between two fictional basketball teams: The Brighton Bombers are scheduled to play a Monday night home game against their rivals, the Revere Redcoats. The Bombers are having a terrible season, and their record sits at 6-21. On top of that, they are playing their second game in consecutive days, and their star player has a wonky ankle. The Redcoats, on the other hand, are having a fantastic season. Not only are they off to a 19-8 start, but they are well-rested and healthy. Without any influence from the betting public, the line would stand at Redcoats -9.0. However, the Bombers have a rabid fanbase who will typically place bets on them out of sheer loyalty alone. Not only that, but the majority of bettors are unaware of the fact that so far this season the Redcoats have performed significantly better on the road. Due to these factors, an intelligent bookie has correctly set the line at Redcoats -7.5 in order to encourage more action on them.
Another facet of this discovery that intrigued me was that in order to consistently win bets, an informed gambler does not actually have to outsmart Vegas (a daunting task), but simply has to outsmart the aggregate masses of people placing money on a given contest.
The next question was this: Could I discover a consistent flaw in the betting habits of sports bettors? Was there some trend that the general population almost always overlooked, and that was taken into account by Vegas when setting their lines? Possibly due to the fact that I was in the mindset of envisioning oddsmakers as social psychologists, or more likely due to the fact that I already had some knowledge of it as a result of my time as a college Psychology major, I decided to use SPSS (or Statistical Package for the Social Sciences) software to analyze historical betting data in an attempt to spot statistically significant trends.
Sidenote: Why did I choose to analyze NBA games you might ask? In all honesty I am actually not a fan of the NBA, but I wanted to pick a sport that people frequently bet on and that had a large enough schedule to provide an adequate sample size.