For most baseball bettors, the urge to bet the favorite is often too tempting to pass up. After all, the favorite is “supposed” to win, while the underdog is “supposed” to lose.
The key for sports gamblers is to determine if the price on the favorite is a true estimation of the team’s likelihood of winning the game. A favorite of -150 with a true probability of winning two out of three games is a good bet in the long run, while a favorite of -240 with a true probability of winning two out of three games, is not.
For the most part, baseball bettors are far more likely to see the second scenario, as opposed to the first, as the oddsmakers know that the majority of baseball bettors are going to back the favorite, and they will adjust for that fact.
A seven year study of baseball results produced the following winning percentages and betting results:
Underdogs: 6917-9644 -153 units
Favorites: 9619-6891 -641 units
Even though the favorites won at a healthy 58.3-percentage clip, bettors who backed only the favorites would lose four times as much as a bettor who backed only underdogs.
But since both scenarios will show a flat-rate loss, what we’re looking for are certain situations that occur, where we can take advantage of the oddsmakers’ tendency to inflate the line on the favorite, and look for value with the underdogs.
Favorable betting situations
The one area underdogs have performed the best is in divisional games, as during the study, the underdogs won 3414 games and lost 4513, but showed a profit of 191 units. On the other side of the equation, non-divisional and interleague underdogs were 4401-6434 and showed a loss of 341 units. So it obviously makes sense to give divisional underdogs a bit more consideration.
In the study, underdogs also performed better when coming off a victory, after scoring 10 or more runs, and in the first game of a series, but didn’t perform as well as the divisional underdogs.
Underdogs also showed a slight profit the game after being shut out, which makes sense, as the oddsmakers force the backers of the favorite to lay a little extra against a team struggling to score runs.
As the study shows, a bettor isn’t going to make money backing every favorite or every underdog, but it also shows the importance of looking for underdogs in the right situations. While you will probably win less than half of your underdog wagers, you can still show a nice profit, which is one of the great things about betting on baseball.