MLB Betting Against the Public 2010 Midseason Review

  • MLB All-Star Break Update July 2010

The All-Star Break is here, so the team at SportsInsights decided to see how “Betting Against the Public” has fared during the 2010 Baseball Season so far.  Half a season of baseball means that almost 1,400 baseball games have been added to our database. Let us see how the additional games did with respect to out contrarian sports investing philosophy.  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 (2003-2010 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, SIs’ proprietary “betting percentages,”  Our research team also “cleans” our data with various systematic techniques — as well as “by hand” — to ensure our historical data is useful for our research articles and our Members.  SIs’ 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 18,000 games over the past 7-1/2 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

At the start of the 2010 baseball season, we presented the following table based on the previous seasons, as noted.  We showed the split between Home teams and Visitors and noted that Home teams performed better using this simple contrarian approach.

Table 1: MLB and Betting Against the Public (2003-2009 Seasons)

Betting % Home Visitor Total
50 +92 units -110 units -18 units
40 +71 -43 +28
30 +52 +8 +60
25 +50 -34 +16
20 +12 +17 +29
15 +17 -7 +10

Using the Table

  • In addition to overall “Bet Against” results, we have broken down how Betting Against the Public works for Home teams or a Visitors. 
  • 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 +52 units.
  • On the other hand, Visitors with less than 30% of the bets (more than 70% of bets on Home team), resulted in +8 units.
  • Some members may try using Home teams at the 25% level and Visiting teams at the 20% level.

2010 MLB Results, to Date

Now, let us fast-forward to the present and see how this season has progressed for “Betting Against the Public” in Major League Baseball.  The results for Home teams continue to stand out.  Visiting teams continue struggle, except for extremely lopsided-bet games in the 20% range.

Table 2: MLB and Betting Against the Public (2010 Season ONLY, up until All-Star Break)

Betting % Home Visitor Total
50 +12 units -34 units -22 units
40 +22 -25 -3
30 +12 -21 -9
25 +2 +5 +7
20 +9 +10 +19
15 +1 +8 +9

A Look at Volatility in Sports Investing

As our Members know, sports investing has ups and downs just like the stock market.  We pulled up a quick graph of this season’s performance for betting against the public — on home teams in the 30% range.  If you look at the chart, you can see that this method earned +12 units this season, to date.  There are fairly wide swings of -7 units or so, even though the equity curve is generally positive.  Sports investors must be aware of the ups and downs of any marketplace and stick with their system.

Graph 1: Equity Chart for MLB – Betting Against the Public on Home Teams Only

30% level (2010 Season through All-Star Break)

MLB Cumulative Results

For your convenience, we tabulated the cumulative results for betting against the public in MLB from 2003 until the present.

Table 3: MLB and Betting Against the Public (Cumulative 2003 until All-Star Break)

Betting % Home Visitor Total
50 +104 units -144 units -40 units
40 +93 -68 +25
30 +64 -13 +51
25 +52 -29 +23
20 +21 +27 +48
15 +18 +1 +19


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.