Physics Of A Softball Bat Explained

By Isaiah Laplant | Softball

Jan 27

There are a great number of questions regarding the performance of a softball bat and how much one bat varies from another. What are the best softball bats made of? That is one of the questions that have been around for years. To be able to answer it, a close look at the physics that goes into the engineering of a softball bat is required.

The basic act of a bat hitting a softball is one of a violent impact. Peak forces reach huge values in the process that enables the ball to reverse its direction and potentially gain speed. Do all bats react the same to the impact? No. During the collision, a phenomenon called “trampoline effect” takes place. However, it is only common to hollow bats (composite or metal) and doesn’t apply to the wooden bats. The phenomenon implies that the barrel of the bat compresses and expands during the contact, which allows the ball to absorb more energy in the process.

How much do the best softball bats weigh? It would appear to be common sense that the lighter the bat is, the easier it is to handle. However, there’s another thing to mention. The mass of the bat directly impacts the velocity of the batted ball. On one hand, faster swing speed leads to increased velocity of the impact. On the other hand, a heavier bat packs more punch and that affects the distance the batted ball travels just as well. Both of those facts are proven. To find the optimal middle ground, it is important to take into consideration another parameter: mass distribution. The closer the center mass is to the handle of the bat, the easier it is to swing. This translates into hollow bats having an advantage over the wooden bats. The hollow barrel allows the balance point to be located closer to the handle, which leaves room for the bat to pack more weight and at the same time swing at a faster speed. This is called moment-of-inertia and is commonly referred to in the sports world as “swing weight”.

It’s common knowledge in the world of softball that every bat has its own “sweet spot”. Physically speaking, the equivalent of that would be what’s called the center-of-percussion, the spot where the contact with a batted ball would produce the least amount of counterforce which is close to 0, experienced by the batter’s hands. However, it’s important to note that it has been demonstrated that the center-of-percussion does not create the maximum batted ball speed. Simply put, it doesn’t increase performance in any way as much as it generates the best feel to the batter.

Durability is another parameter where aluminum bats are superior to their wooden counterparts. They were introduced in college baseball in 1974 due to financial reasons and concerns that the wooden bats were breaking at a high rate. One of the most visible advantages is on the inside pitches, where a wooden bat is far more vulnerable to break at the handle than a hollow one. However, this doesn’t mean they can’t be damaged. Hollow bats, especially ones with thinner barrel walls, are exposed to cracking or denting. This eventually led to a different, short-lived type of softball bat: the Titanium. It allowed for a thinner single-wall than aluminum would, which increased performance without the risk of cracking so much that not shortly after they were introduced in 1993, the titanium bats were banned from the world of softball.

To add to the list of differences between the aluminum and wooden, we can go beyond anything related to performance, and mention that the two sound completely different at the contact with a softball. A wooden bat would go “crack”, while an aluminum bat would go “ping”. Even though the sound of the aluminum barrel is related to the trampoline effect that overall increases performance, this aspect is merely an aesthetic matter of personal preference.

Keeping everything mentioned above in mind, it’s time to summarize and conclude. While hollow and wooden bats respectively vary in everything from sound to weight and mass distribution, the optimum for each batter differs from one to another and the issue of finding the best possible softball bats is one of meeting personal strengths, physical attributes and preferences, more than anything.

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