MLB Baseball Betting–The Impact of Weather


On balance, there may be no factor discussed in sports betting circles more overrated than the weather. It’s far more significant in horse racing where some horses simply don’t want to run in bad weather, other horses are indifferent and some actually take to the mud and the slop. Ask Calvin Borel how that works—he guided Super Saver to victory in the 2009 Kentucky Derby as a 50/1 longshot with the rest of the field seemingly bothered by the muddy track at Churchill downs.

In sports, it’s a completely different matter. Every player on both teams is dealing with the same weather—it plays no favorites. In baseball, if the weather gets too bad they quit playing. At one point, football was different and they’ll still play in the rain and snow but if there is a hint of lightning they act as if a nuclear blast is imminent. The playing field and stands are cleared and the game halted until conditions improve.


Weather does have some bearing on handicapping sports. It likely plays a more significant role in baseball than football or any other sport. Here’s some of the things to look for when checking the weather for the day’s MLB card:

RAIN: Major League Baseball rules provide for the stoppage or postponement of a game due to weather or ‘field conditions’ but provide little guidance beyond that. That’s why you’ll sometimes see a game suspended for a light sprinkle and other times see the players trying to solider on through a veritable deluge. Before the game, the home team manager is responsible for making a decision on the weather and/or field conditions. Once the home team manager hands his lineup card to the umpire it becomes the sole discretion of the umpire-in-chief about whether a game should be postponed or delayed due to rain or other weather conditions. Umpires are required by the rules to wait at least a half hour to see if conditions improve. In general, they’re encouraged to complete games if at all possible which results in the interminable rain delays familiar to any baseball bettor. A game is official after 5 ½ innings of action except as all baseball bettors know that doesn’t apply to totals. MLB totals aren’t official until 9 innings of action (8 ½ innings if the home team is ahead).

WIND: Wind is arguably the most important weather information for the baseball handicapper. The old adage is that playing ‘Under’ the total is advised when the wind is blowing ‘in’ while the ‘Over’ is the play when the wind is blowing ‘out’. The problem with that is that wind has a tendency to be very uncooperative and change direction and velocity without regard to your baseball bet. Another problem is that the weather report for a given day at a specific stadium isn’t exactly a ‘state secret’. That means that any wind issue significant enough to impact totals betting has already been ‘baked into the line’. It also means that every ersatz ‘wise guy’ from here to Australia is betting ‘Over’ if it’s blowing out and ‘Under’ if it’s blowing in. That means that you can often find value by being a contrarian and going the other way. The moral of the story is that sports betting and handicapping isn’t as easy as just betting one way or the other due to the direction of the wind.

Serious baseball betting enthusiasts are more nuanced in their use of weather. They become familiar with the dimensions and other characteristics of individual stadiums. They also become familiar with the tendencies of a team’s starting pitchers. A starter that throws a lot of ground balls will be less affected by wind than a fly ball pitcher. There’s also a matter of how the wind is blowing—a steady wind of any velocity is easier to deal with than gusty winds that make it difficult to judge foul balls.

HUMIDITY: Understanding the role of humidity in a team’s local weather can also be valuable. Generally speaking, a hit baseball travels a greater distance in low humidity conditions (dry air) than in high humidity conditions. The air is literally ‘heavier’ in one extreme as anyone that has traveled from Las Vegas to Atlanta in the middle of the summer can tell you. Of course using humidity as a handicapping factor puts us right back where the wind blew us—we’re basing a play on ‘public information’ available to the linesmaker and any bettor with the initiative to look it up. Much like the wind, you should be mindful of humidity but not to the point that it is your sole reason for making a bet.

SUN: Sun isn’t a huge problem for players, nor is the lack of sun on a cloudy day. What can be difficult is partly cloudy days. Even more difficult are situations where players have to go from sun to shadow and back again to play the baseball. Another similar situation—a batter in the sun with a pitcher throwing from the shade or vice versa. Major League Baseball teams usually schedule games to avoid these situations but keep an eye out for unusual start times—particularly in the late afternoon. To properly leverage this information a bettor must be very familiar with the sight lines and lightning at a specific stadium. Properly applied, this is a good way to find very strong over/under bets in baseball.