Are MLB Teams Undervalued After Losing the First Game of a Doubleheader?

Much like the work of Adam Savage and Jamie Hyneman on their fabulous television program, one of our favorite things to do at Sports Insights is play the role of Mythbusters. Very little gives us more pleasure than taking a popular, widely held theory and debunking it. In fact, that’s one of the core aspects to our contrarian philosophy.

The Latin phrase argumentum ad populum essentially says that if everybody believes something, then it must be true. However, our history of betting against the public tells us that the general population is typically wrong. We have also written at length about how it is profitable to bet against ranked College Football teams, fade NFL teams in “must-win” situations, take NBA underdogs after a blowout loss and pound the over in bad weather NFL games. All of these systems disproved largely accepted opinions that many bettors believed for years.

For years bettors have attempted to explain how teams that lost the first game of an MLB doubleheader would be undervalued in the second game. The idea was simple: teams would be hung over from their Game 1 victory and would therefore be more likely to rest on their laurels in Game 2.

Bettors have speculated that there are a number of factors playing into this theory:

  1. Bullpen usage: Teams are more likely to use their top relievers if they’re winning
  2. Sense of urgency: Teams who lost their previous game are likely to be more motivated
  3. Familiarity: Historically underdogs have been undervalued when teams are familiar with each other. This includes teams in divisional games or when facing an opponent for the second time in a season.
  4. Lineup strategy: Managers have to be careful with player fatigue and will be more apt to hold their star players out of the starting lineup if they have already posted a win.

If you’re familiar with our work, you already know that when a belief is almost universally held by the public, we will always go against the grain and take an opposing viewpoint. Since the general public believes that underdogs coming off a loss would offer value to bettors, we hypothesized that the exact opposite would be true.

Using our Bet Labs software, we found that MLB teams who lost the first game of a doubleheader have gone just 121-127 (48.8%) with -7.94 units lost in the second game. When you focused on dogs fitting these criteria, the system dropped to 53-78 with -8.96 units lost.

Clearly there is no advantage gained by betting on teams who lost the first game of a doubleheader, but another edge was clearly visible. Since 2005, favorites have gone 146-101 (59.1%) with +6.76 units won in Game 2 of a doubleheader. When that team was also favored in Game 1 of the doubleheader, the record improved to 112-68 with +11.78 units won.

Favs, Favs in Pvs Game

When teams fitting this criterion are victorious in Game 1, our units won remains almost unchanged (+11.59) but the return on investment nearly doubles from 6.5% to 11.1%. This provides further evidence that teams don’t bounce back from a loss in Game 1 of a doubleheader. Going one step further, we find that favorites have gone 41-13 (+19.93 units won, 34.4% ROI) after winning Game 1 by at least 3 runs.


Having disproved the theory that teams who lost Game 1 of a doubleheader are undervalued in Game 2 and discovered that favorites have been historically profitable when teams play two, we wanted to unearth additional trends that have been profitable in the second game of a doubleheader. Unfortunately, it’s very rare that favorites fit our betting against the public philosophy, so we’ll have to look elsewhere for lucrative trends.

  1. Road teams have gone 115-113 (+1.27 units won) & road favorites have gone 45-34 (+5.56)
  2. Favorites have gone 83-52 (+8.73 units) when the total is at least 9
  3. Favorites have gone 74-56 (-1.54 units) in divisional games, but 72-45 (+8.30 units) in all other games
  4. Game 1 winners have gone 49-34 (+14.00 units) when Game 2 is played at 8PM eastern time or later. In all other matchups, the Game 1 winner has gone just 78-87 (-13.26 units)
  5. Game 1 winners have gone just 42-55 (-14.84 units) in weekend doubleheaders, but that record improves to 85-66 (+15.58 units) during the week.

Have any questions for the staff at Sports Insights? Utilize our live chat to speak with a customer service representative or e-mail us at help@sportsinsights.com.

David Solar is the Content Manager for Sports Insights and can be reached directly at David@sportsinsights.com.

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David Solar

David Solar has been the Content Manager at Sports Insights for over four years. He specializes in sports betting analytics and has created several popular data-driven betting systems. He can be reached directly at david@sportsinsights.com or on twitter at @TheDavidSolar.

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