MLB Betting Against the Public 2003-05

  • MLB Betting Statistics

This is an update to last year’s baseball article on MLB betting statistics. will update key statistics for MLB to include the 2005 season.  This gives us three seasons’ worth of data instead of two: a nice 50% increase in “reliability of results.”  Interestingly, the results are now an even closer match to the results we have seen in other major sports.

These robust results strengthen our conviction that Betting Against the Public” and “Smart Money Methods” are powerful approaches for any sports investor.  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 (Betting Statistics from 2003-05 Seasons)

Our database for baseball covers almost 6,500 games over the past three seasons.  Our study includes all MLB regular season games, as well as playoff games (but excludes spring training).  We used rules similar to those used in other articles and studies to clean the data and ensure the integrity of the results.

  • Did not use data if Public % was 0% or 100%
  • MLB data from 3/03 – 10/05 (6,480 games)

Baseball is a slightly different animal because it uses a “money line” for betting purposes – as opposed to a “point spread.”  As a result, we show the actual number of “units won or lost” over the past two seasons – as well as average units won per bet.

Betting Against the Public

First, let’s take a look at the cumulative results for the three seasons from 2003-2005.  Table 1 shows the results of Betting Against the Public at various levels of “Public Betting Percentage.”  Results are positive at every level of public “disfavor.”

Table 1:  Betting Against the Public and MLB (Three Seasons 2003-05)

Public % (X% or lower) # Games Units Avg Odds Units/Game
50% 6,317 +40.0 +133 .007
40% 4,380 +38.3 +142 .009
30% 2,393 +78.0 +149 .033
25% 1,555 +49.9 +151 .032
20% 842 +7.5 +151 .009
15% 369 +11.2 +147 .030

Some interesting points to note:

  • The maximum “number of units won” is at the 30% (or lower) threshold.  Note that these figures take into account a reasonable “vig.”
  • Many experienced baseball bettors like to take the “underdog” in baseball.  As usual, the public loves to take the winners (and thus, the favorites).  Fading the public leads to taking the “dogs” and receiving odds of about +150.  Note that this approach doesn’t win 50% of its wagers – but wins enough to make it a profitable proposition (given the odds received).

Although cumulative (2003-2005) results are positive at various levels of Public Betting Percentage, 2005 saw the “50% and 40% levels” suffer losses.  By various measures, 2005 was a difficult year for baseball underdogs.  We would note, however, that the “30% and 25% percentage levels” achieved decent gains.  In addition,’s Square Plays were positive.

Perhaps, most telling, MLB results now falls in line with the results we have seen in the other major sports.  That is,“Betting Against the Public” gives you an edge – particularly in the 25%-30% range.  This robust result increases the potential reliability of much of our research.

Smart Money Approaches also updated our results for “Smart Money” methods.  “Line Moves” – with Public % in the Opposite Direction of the Line Move – are a proxy for where the Smart Money is going.  This approach reduces the number of games (and units won) – but improves significantly: the winning percentage, and units won per game.

Table 2:  Public Betting Percentage and Line Move (>=10) in Opposite Direction

Public % (X% or lower) # Games Units Avg Odds Units/Game
50% 1,247 +48.3 +124 .039
40% 870 +44.6 +130 .051
30% 478 +39.2 +137 .082
25% 307 +33.8 +140 .110
20% 164 +18.9 +143 .115

Note that even with 2005 being a difficult year for MLB dogs – every “Public %” bucket in Table 2 saw gains.  Smart Money methods are indeed powerful methods that help SportsInsights’ members gain an edge.  Now, let’s “Play Ball!”


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.