Baseball Science 101: The Physics of Hitting a Home Run
Science Tips and Tricks to Hitting a Home Run
Don’t worry! We know that when you are heading up to the plate, the last thing on your mind is the physics equations needed to calculate the best home run hit. However, we are going to give you some basic scientific knowledge that you can apply to your hitting to maximize your chances of hitting home runs.
First, we turn to the expertise of Professor Alan Nathan at the University of Illinois. He is an expert in the physics of baseball, as well as the interactions of subatomic particles – but we’ll leverage his baseball science expertise. In a recent Washington Post article, he said that there are two basic elements of a superior home run:
- Exit speed – the speed at which the ball leaves the bat.
- Launch angle – the optimal angle is between 25 – 30 degrees.
Of course, a number of other factors can also impact the hit including air density (elevation, air temperature, air pressure, humidity) and wind speed. However, let’s look at the basic elements the hitter can control. We’ll focus on increasing exit speed.
Boost Exit Speed with Two Factors: Bat Speed and Mass
To add distance to the hit, it is a priority to increase exit speed. This can be done in two ways:
- Increasing the speed of the bat (swing speed) – For example, doubling the swing speed of a 30 ounce bat can raise batted ball speed from 62 mph to almost 84 mph, which represents a 35% increase. A 1 mph swing speed increase can extend the distance of the hit by 8 ft.
- Increasing the mass of the bat – Although research shows that the maximum ideal bat weight is 41 ounces, most pro players prefer 31-32 ounce bats as it allows greater maneuverability with minimal power loss.
Mastering the Spin
When confronted with a pitch, the batter needs to think quickly – assess and react to compensate for (or work with) the spin on the pitch to maximize the likelihood of a home run hit.
- A Curveball – With topspin of 1,900 rpm, the batter can build on the pitcher’s topspin and create 45% more backspin off the bat, resulting in curveballs being easier to hit farther.
- A Fastball – With backspin of up to 1,800 rpm, the batter must try to counteract the spin to reverse the rotation of the ball to give the ball lift with backspin. Clearly, this is a more difficult task than the curveball’s topspin, which is already working with the hitter’s goal.
Speed Thinking
Popular Mechanics does a great job of analyzing the milliseconds between a pitch and a hit. The basic principle is this: a hitter has mere milliseconds to analyze the pitch, decide what to do and then actually follow through with the hitting plan. Not much time, so get that brain trained up so you reaction is second nature and you can think fast.
Good Vibrations?
When the ball hits the bat, the bat vibrates and the energy can be transferred back to the ball instead of through the bat and into the player’s hands – otherwise known as “sting”. The deciding factor as to where the energy is transferred is the location of the hit on the bat. A hit in the “sweet spot” or zone (as identified by Physicist Rod Cross, University of Sydney in Australia), produces minimal vibration and delivers more energy to the ball vs. the hitter’s hands.
How Can This Science Help Me Hit More Home Runs?
The reality is that the old saying, “Practice makes perfect”, is true. Understanding the science and factors behind the ultimate home run can guide you on what to work on during your practices:
- Increasing bat speed and perfecting launch angle resulting in extended distance
- Quickly identifying pitches and making instant decisions to conquer spin
- Targeting hits in the “sweet spot” for optimal energy transfer
If you want to read more about the science behind baseball, check out The Physics of Baseball Bats.