MLB Betting Against the Public 2003-08

  • Article — MLB and Betting Against the Public (Includes 2003-08 Seasons) March 2009

As a leader in sports information services, SportsInsights is pleased to update our research on baseball statisticsand the recent performance of “Betting Against the Public.”  Contrarian “sports investing” worked particularly well in Major League Baseball last season.  With almost 14,000 data points over six seasons, baseball continues to show impressive statistical results.  In addition, with many sports winding down just as baseball is starting up, baseball will soon be the “only game in town” for some sports investors.  But what a game it is: with a 162 game season and 30 teams, there are plenty of profit opportunities!  The information on this site is for entertainment and educational purposes only. Use of this information in violation of any federal, state, or local laws is prohibited.

MLB Database (2003-2008 Seasons)

SportsInsights (SIs) has collected betting data for every major U.S. sport since the 2003.  We collect the opening and closing lines (and “line movement,” for various sportsbooks) as well as final scores — and perhaps most importantly, Sports Insights’ betting percentages.  Over the years, SI has put together software and systems that minimize downtime and collect data more regularly and cleanly.

Our research team also “cleans” our data with various techniques “by hand” to ensure our historical data is useful for our research articles and our Members.  SI’s historical database for each sport is an important part of our research and value-added for our Members.  It is the backbone for our contrarian sports investing  methods and you can’t find this kind of data and information anywhere else!  

SportsInsights’ database for MLB now includes almost 14,000 games over the past six seasons.  For the purposes of this article, we include the playoffs, but exclude spring training.  Similar to hockey, baseball is a “moneyline” sport, so that we emphasize “units won” (and not winning percentage).

Betting Against the Public

Similar to last year, we present results for “Betting Against the Public” at different thresholds of betting percentageAND for home teams and visiting teams.

Table 1: MLB and Betting Against the Public (2003-2008 Seasons)

Betting % Home Visitor Total
50 +103 units -54 units +49 units
40 +91 -30 +61
30 +64 +13 +77
25 +67 -46 +21
20 +20 -4 +16
15 +28 -5 +23

Using the Table

  • In addition to overall “Bet Against” results, we have broken out how Betting Against the Public works if a team is either a Home team or a Visitor. 
  • For example, if a Home team has less than 30% of the public betting on them (Visitor has more than 70% of the public), this scenario resulted in +64 units!
  • On the other hand, Visitors with less than 30% of the bets (more than 70% of bets on Home team), resulted in +13 units.
  • It’s important to note that the Betting Percentage data used in our articles comes from Sports Insights’ propriety betting percentage data. We collect betting data from seven online sportsbooks. No other site in the world offers a more complete picture of the sports betting market.

Contrarian Investing, Odds and Psychology

Like most major sports studies, there is “value” in selecting underdogs.  In a moneyline sports such as baseball and hockey, historical data shows that picking underdogs — that pay out more than you risk — is the best way to “keep the wind” at your sports investing back.  This may result in winning only 40%-45% of your selections, but the long odds means you’ll have positive Units Won.

Why does this work?  Psychologically, contrarian sports investing makes a lot of sense.  Most casual bettors like to watch a game and say that they “picked the winner.”  This is why many fan favorites or championship-caliber teams are over-valued and do poorly “against the spread.”  Most sports fans like to bet on heavily-favored teams like the Yankees or Red Sox and happily watch their team win 55% or 60% of the time.  However, they forget that they might be laying -200 moneyline odds (or betting $200 to win $100).  Many of these fans who lay heavy odds (or in other sports, lay a lot of points) shrug their shoulders if they see themselves losing money because they know that their team seems to be winning around 60% of the time (even as their bankrolls dwindle).  In the long-run, if you continue to lay heavy (-200) odds and win even 60% of the time, you will lose your hard-earned cash.  

On the other hand, SportsInsights’ proprietary betting percentages can help you see which teams the Public loves too much.  We can then “bet against” these over-valued teams and seek out contrarian value.  On average, SI’s methods such as betting against the public or smart money methods have our Members betting on undervalued underdogs.  “Sharp bettors” and our Members often find value on underdogs that are ugly — but with moneyline odds and point spreads — can be profitable over the long-run.

Some Notes

  • The contrarian “30% bet against level” continues to be the largest profit-maker in terms of units won.  The “30% level” also results in more consistency between Home and Visitor plays; that is, both Home and Visitor selections have been positive over the entire six-year dataset.
  • Last year, we noted that Home teams seem to be undervalued in major league baseball when “betting against the Public.”  After last year, this “trend” is even more evident.
  • Higher or lower “Betting Percentage” thresholds will increase or decrease the number of plays respectively.
  • MLB Square Plays had a good 2008, winning more than 45% of the Square Plays and picking up +36 units.
  • *It’s important to note that the Betting Percentage data used in our articles comes from Sports Insights’ propriety betting percentage data. We collect betting data from seven online sportsbooks. No other site in the world offers a more complete picture of the sports betting market.

We do not guarantee that the trends and biases we’ve found will continue to exist. It is impossible to predict the future. Any serious academic research in the field of “market efficiencies” recognizes that inefficiencies may disappear over time. Once inefficiencies are discovered, it is only a matter of time before the market corrects itself. We do not guarantee our data is error-free. However, we’ve tried our best to make sure every score and percentage is correct.