Bat Compression Test Results

Bat compression test results describe the pressure required to compress the barrel of a bat. A higher compression result (usually in pounds per area) means a barrel’s walls are more rigid. A bat with lower compression means the barrel walls are more flexible or elastic.

Some believe that a more elastic barrel wall can produce faster exit speeds. According to every manufacturer and bat engineer we spoke to, that belief is invalid. We discussed the topic with every major manufacturer and compiled their sentiment, as we understood it, below.

Baseball and Softball Bat Compression

Bat compression can be a valuable tool to estimate the performance of a given bat construction, but taking the compression value without reference will rarely provide an accurate measure of actual bat performance.

~Kyle Hodge, Product Engineer, Axe Bats

Accurate compression testing has historically been a slightly useful indicator of ball exit speeds. But non-linear designs, standard in performance bats, make compression tests less helpful in predicting exit speeds. Also, quick and accessible compression measurements, made possible by field-level compressors, lack the precision required to directly correlate to ball exit speeds.

Measuring only how loose the springs are in your trampoline tells you virtually nothing about how high you can jump.

~Brian Duryea, Bat Digest

We asked several industry experts from a major manufacturer to comment on the usefulness of bat compression. Read below what they had to say about bat compression tests’ predictive power of ball exit speeds.

Bat Compression Test Results

Here is a sampling of compression tests we took on bats at Bat Digest. As we say in this article, making full-on determinations about ball exit speeds based on these numbers doesn’t mean very much.

Comparing BBCOR, USA, and USSSA Compression Test Results

The Trampoline Thought Experiment

Non-linear bat designs, like this 4-piece Rawlings BBCOR Quatro, can have an exception with certification labs for a lower compression value than other bats in the same class. The lower allowed compression says more about the unique design than it does about ball exit speed. (Although, we do love its ball exit speed.)

One useful way to visualize how easier compression is not always better is to consider the trampoline in your backyard.

Can you jump higher or lower as the springs become looser on the trampoline?

The answer depends. Specifically, how much does the person jumping weigh? How much elasticity is retained in the springs as they loosen? We could imagine an equation that optimizes the trampoline’s effectiveness. That equation, based on factors like the jumper’s weight, leg strength, and the quality of the spring’s recoil, would set the optimal amount of tautness in the springs.

Much like the perfectly dialed-in trampoline, a bat’s effectiveness is not always maximized by merely making the barrel walls more flexible. Instead, the right elasticity depends on factors like pitch speed, bat and ball weight, and the quality of the barrel’s material. Optimal compression is one factor in ball exit speeds, but it is far from the only one.

In other words, measuring how loose the springs are in your trampoline tells you virtually nothing about how high you can jump.

When measuring within the same class of bat (BBCOR, USSSA, USA), our bat compression test results provided little predictive power for exit speed.

Measuring the Life of a Single Bat

One general theme we gathered from the experts was that bat compression test results are useful in monitoring the life of a bat. As a composite bat is worked in more, its compression becomes easier.

We also spoke with some engineers at DeMarini who felt, much like everyone else, that bat compression done at the field level (with devices like the one you see in the video above) isn’t reliable. Most bats in a particular classification sit very close to each other on a compression test scale. Small changes from one bat to another aren’t predictive enough, nor is the device accurate enough, to determine ball exit speeds.

Compression doesn’t matter to me; I’m hitting bombs either way. Hitters should focus less on barrel compression and more on swing mechanics, timing, and approach at the plate. Blaming your bat for a bad AB is counter-productive.

~Former Oregon Duck, Hailey Decker

Here are some notes we took from our conversation, paraphrased as we understood them.

Anyone who has swung DeMarini’s top-shelf fastpitch line generally loves it. Fastpitch players are much more familiar with compression tests than baseball players. Although many significant tournaments use compression tests to disqualify bats, compression is not a foolproof indicator of exit speeds.

• Lower compression does not necessarily mean better performance, especially when considering tee work, soft toss, and game speeds.
• Incoming pitch speeds matter when considering the optimal barrel compression, which isn’t always the lowest.
• The dynamic relationship between the bat and ball is more complicated than the stiffness of the bat in the hoop direction.
• Compression is measured but not used for performance testing certification for a reason.
• Barrel compression results in certification testing come from precise lab equipment, not on-field testers, which can lack accuracy.

Bat Compression Testing: Industry Experts Take

Axe Bats builds the backside of their bat’s barrel differently than the front, which is made possible by the ergonomic handle that ensures hitting on one side of the barrel. In turn, the compression numbers for an Axe barrel do not align with those of other manufacturers. It’s just one of many non-linear designs that make today’s barrel compression results less useful.

An Easton engineer shared a similar view, noting that the difference between compression and exit speeds is uncorrelated enough to diminish the value of compression tests alone.

“In the current landscape of many associations/leagues, there seems to be a misconception that bat compression is the end-all, be-all of performance. Compression is the easiest outer-most layer that can be easily measured, but many factors beneath that compression figure impact the bat’s performance…”

Henry Fitzpatrick, Bat Engineer

Those factors include, among other things, the material’s quality and durability.

Rawlings expressed a similar sentiment. Compression made more sense as a stand-alone performance test long ago. Now, with non-linear construction, bats aren’t designed with a single set of characteristics throughout the barrel. As such, measuring pressure at one point and calling it a performance comparison is not accurate.

When do Compression Numbers Matter?

Easton’s Ghost X is a great example highlighting the value of factors other than barrel compression. People love this bat not just for its ball exit speeds but also for its feel on hits and mishits and the durability of the composite.

Compression numbers matter in a few specific instances.

1. Some leagues (mostly in softball) require your bat to be above a specific compression. These field-level tests attempt to remove bats that are too hot. Although leagues can enforce these standards, it is far from a pure performance test. Some bats removed due to compression measurements have passed standard tests.
2. If you’re looking to buy an illegal/doctored bat that has been shaved or rolled, then pre- and post-procedure compression tests can confirm if the bat was manipulated. Compression tests are standard among those who sell illegal bats.
3. Compression test results can tell you how well your bat has been worked in. Our intent at Bat Digest is to provide parents and players with a compression number and how many hits it takes to improve a bat’s compression. You’ll find that data on our raw exit speed page.