Any fantasy baseball owner who has had a night ruined by rain showers, rain delays and other weather concerns knows the importance of checking the forecasts before the first pitch. This is especially true for those who play MLB DFS, but avoiding deferred games is only part of the climate equation. You can use weather conditions such as heat, wind and humidity to your advantage, and The nightly MLB weather forecasts from RotoGrinders and exclusive WeatherEdge tool are the best ways to gain that advantage and dominate your matches.
Here’s a brief overview of how different weather elements can affect MLB games, as well as an example of what I do every day at RotoGrinders to help you avoid the ugly weather and target the games where the weather can help.
MLB Weather: Rain predictions
The first step in making a winning line-up is to avoid the zeros associated with cancellations. I start the day at RotoGrinders with a general color-coded prediction for each game based on how things look, then I gradually refine that prediction as we get closer to the first roll. In the early afternoon, I look at high-resolution hourly forecast models that help me get a little more specific about the timing of potential storms. The most important time frame is the last hour to roster lock. At that point, it is more about reading / analyzing radar and less about looking at prediction models. Throughout that process, we also have an automated forecast tool, so you can see an updated forecast at any time of the day.
If you know which games can rain, which games are delayed in the game and which games play well after a late start, you can avoid the donuts and find gems in other games people might be too scared to play.
Rain is the most crucial part of MLB forecasts, but other factors such as wind, heat, altitude and humidity also play a key role in the outcome of games.
MLB Weather: wind forecasts
It doesn’t take a degree in meteorology to figure out: if winds blow from the home plate to the outfield, that wind will literally help the ball carry the ball on a deep fly over the fence. When wind blows, it has the opposite effect. Certain parks are very sensitive to wind and the results can be extreme. In Wrigley Field, a wind blowing at 10 mph or more increases home runs by about 50 percent, while a wind above 10 mph decreases HR by 33 percent. That’s a huge fluctuation in results based purely on wind orientation.
To make it even more interesting, each stadium responds a little differently to wind. Let’s use Wrigley’s 10 mph example and apply it to Oracle Stadium in San Francisco. Here the result of a wind of 10 plus mph wind represents only a six percent increase in HRs. This margin is purpose built to minimize wind impacts from this direction, so the results make sense. Each park has its own microclimate, and we looked together with WeatherBell (a weather data company) to see how each park is affected by different weather conditions. You can use the MLB WeatherEdge tool to try it out for yourself.
MLB Park Factors
The higher you are, the thinner the air becomes and thus the further a ball goes. Thinner air at height can also affect fields. When there is less air resistance on the ball, it is more difficult to break a breaking ball. There’s a reason Coors Field is on or near the top of baseball fields to score every year.
MLB Weather: temperature influences
The best way to explain this is to simply say that hot air is thin air and cold air is dense air. The warmer it is, the better it is for hitters, as the ball continues to carry in hot, thin air. In the following examples at Yankee Stadium, wind is not a significant factor in either data set (just four miles per hour in the first game and blowing across the field in the second game), but the hitting conditions are still very different. The first game was played in warm weather and expected HRs were up 14 percent. The second game was played in 35 degrees cooler weather and the expected HR percentage dropped by 30 percent.
MLB weather: impact on humidity
There’s a reason this is the fourth on the list because it’s not as big a factor as the others, but it still matters. Contra-intuitive as it is, moist air is actually less dense than dry air. We already know that less dense air helps a well-hit ball travel further, so that means a warm, humid day has some of the best hitting conditions out there (see: Arlington).
I prefer to use dew point as a measure of humidity and consider dew points around 50 or lower as dry and dew points above 70 as very humid. Again, we can view these parameters on the RotoGrinders MLB Weather page or my new one WeatherEdge tool. Below is a heat / humidity combination in St. Louis, another game where wind is not a significant factor at just four miles per hour, but the high heat and humidity increased the HR rate by 20 percent.
That’s a fair overview of how and why the weather matters for MLB DFS scores. Thank you for reading. If anyone has any questions I am always ready to chat so call me on Twitter, @KevinRothWx.