Prior to the start of the NCAA Tournament, we submitted a betting system to ESPN’s Tournament Betting Guide which explained why bettors should be fading the so-called “trendy underdogs.” This analysis highlighted how bettors could find value by taking favorites receiving less than 50% of spread bets, but we also wanted to know whether we could also uncover historical value on the over/under.
Since the first two rounds are already behind us, we wanted to look at games played in the Sweet 16 or later. With fewer games scheduled during the later rounds, we surmised that each game would receive a higher number of bets. This would undoubtedly lead greater profits when betting against the public and tracking sharp money indicators like reverse line movement.
Our initial analysis revealed that there was limited value betting totals during late-round tournament games as both the over and under produced records of 74-74. Despite this .500 record, we believed that we could build a simple reverse line movement system to track sharp money.
For those who are unfamiliar, reverse line movement refers to line movement that contradicts our public betting trends. For example, if 80% of bettors are taking an under you would expect oddsmakers to lower the total in an attempt to encourage action on the over. If the total increases, it’s an excellent indicator that sharp money (typically large bets by wise guys or betting syndicates) is taking the over.
Using our Bet Labs software, we focused on the performance of unders when more than 50% of bettors were taking the over. Although this only improved our systems record to 70-68, our return on investment (ROI) skyrocketed when the total dropped at least a half-point. As you can see from the screenshot below, this basic reverse line movement system has produced a 33-22 record with +8.99 units won since 2005.
After finding this profitable reverse line movement system on the under, we wanted to know whether the same strategy would prove to be effective when taking the over. Unfortunately, it’s extremely rare that a majority of public bets take the under which makes any sort of reverse line movement system exceedingly difficult. In fact, there are only ten games in our database in which less than 50% of bettors took the over. Moreover, there hasn’t been a single late-season tournament game in which more than 60% of bettors took the under.
Knowing that we would be unable to use our public betting trends to create a profitable betting system, we instead chose to examine how line movement impacted our system’s record. We quickly found that in games in which the total either remained unchanged or increased, the over had gone 49-39 with +7.13 units won and an 8.1% return on investment. When the total rose at least 1.5-points the ROI jumped to 10.7% and when the total increased by at least 2.5-points the ROI jumped to 20.4%.
Essentially, our breakdown of Sweet 16, Elite 8, Final 4 and Championship games is quite simple: If the total goes up, take the over and if the total goes down, take the under.
Bet Labs utilizes opening and closing lines from Pinnacle, so make sure to check out our free College Basketball odds page for the latest lines and betting trends.