SPARTANBURG COUNTY, S.C. (WSPA) — Baseball is in the air and how the game develops is highly dependent on what that air is doing.
Wind has a direct impact on games, giving a long fly ball a push over the fence one day; stopping it well short the next.
Depending on wind speed, we can see an addition or subtraction of roughly 20 to 60 feet in carry.
The hidden gamechanger is the density of the air.
What’s that mean? Denser air means all the air molecules we breathe are packed together more tightly. Denser air puts up more resistance to anything moving through it.
There are a few things that can change that density.
The first is temperature. Warmer air is less dense than colder air. Fly balls fly longer in warmer air.
Studies differ on the amount of difference that makes, but it ranges from 2.5 to 4 feet of extra travel for every 10 degrees warmer it is. An easily catchable fly ball on a 60-degree night will carry another 7.5 to 12 feet on a 90-degree summer afternoon assuming all other conditions are equal.
Humidity plays a role, but it’s small. Water vapor is lighter than oxygen or nitrogen, so humid air is less dense. You might think that would boost home runs in the south, but the change in density is small changing the carry of the ball only a few inches.
Altitude makes a difference; air is less dense the higher up you are. In the big leagues, a 380-foot flyball in Fluor Field’s big brother Fenway Park in Boston could be expected to travel 400 feet at Coors Field in Denver. The difference between Fluor Field in Greenville and McCormick Field in Asheville? Not quite 5 feet in carry for the same hit.
Air density affects pitches, too. Denser air means more drag, which slows down the fastball. but only by a mile per hour or so.
The biggest effect is on breaking pitches. The spinning seams of a baseball grab the air and create higher pressure on one side of the ball. The ball then curves toward the area of lower pressure.
If the air is less dense, the spinning ball grabs less air, and the ball won’t curve as much. A flatter pitch is easier to hit.
Of course, the most disruptive effect from weather is rain. That means the tarp is on the field, and no one wants to see that.