Many sports bettors are attracted to underdogs because they offer plus-money payouts. The idea is that occasional big wins can offset the lower win percentage.
But does this strategy actually work in the long run?
To answer this question, we analyzed all MLB underdogs since 2004.
Historical Results
SU: 20,882–29,390
Win Rate: 41.5%
ROI: -3.2%
Profit/Loss: -$160,917
Underdogs win about 41.5% of games, but betting every underdog historically results in a negative return on investment.
Why Bettors Like Underdogs
Despite the negative historical ROI, underdogs remain extremely popular among bettors.
Reasons include:
• Higher payouts
• Potential for contrarian betting opportunities
• Public bias toward favorites
However, sportsbooks typically adjust odds to account for these tendencies.
Key Takeaways
• MLB underdogs win about 41.5% of games
• Blindly betting underdogs produces negative ROI
• Betting markets appear to price underdogs efficiently
Long-term profitability usually requires identifying specific situational edges rather than broad strategies.
