Failed Experiments: We Tried To Learn Something New About Triple-A Balls


Image credit: (Photo by John McCoy/Getty Images)

It was a very interesting, promising idea.

As Baseball America editor Josh Norris watched multiple Triple-A games during the first two months of the season, he noticed something different about the new Triple-A baseball.

It’s obvious that the MLB ball now used in Triple-A carries further than the old ball, leading to more scoring and more home runs.

But Josh noticed something else. On multiple occasions, he noticed pitchers throwing harder than they had thrown last year. See one pitcher throw a little harder and you write it off as a pitcher adding a tick of velocity. But when you see pitcher after pitcher throwing 1-2 mph harder than they have in the past, it starts to raise questions in your mind. Those questions become stronger when interviews with some of the pitchers found them at a loss for why they were throwing harder.

So that led Josh to ask: was the new MLB ball in Triple-A leading to velocity gains for pitchers in addition to power gains for hitters? After all, a ball with less drag could affect pitchers as well.

To try to find out, we developed an experiment in partnership with Durham, N.C.’s Baseball Rebellion training facility. The idea was that we would test six of the traditional MiLB balls (which are used in all levels of the minors below Triple-A as well as six of the new Triple-A baseballs, which are identical to MLB baseballs with the exception of the names that are stamped on them. Both types of baseballs would be fired from a three-wheeled pitching machine with the same settings, equipped to match the velocities of a Triple-A pitcher. We would measure velocity and movement to see if there were any difference.

Before beginning, it was clear that the baseballs are quite different. Baseball Rebellion pitching instructor Dave Shinskie noticed clear differences in the feel of the leather, the seams and the construction of the different balls. The Triple-A balls just felt harder and more compact.

“(The minor league ball) feels a little bigger. You can tell the difference between the big league ball and this one,” Shinskie said.

But that was anecdotal. We wanted hard data. So we set up the experiment and quickly found that Rapsodo 2.0 pitching units cannot measure data on a ball coming off of a three-wheeled pitching machine.


The Baseball Rebellion staff figured out a quick workaround, Baseball Rebellion founder Chas Pippitt set up a HitTrax unit to measure the velocity and movement of the ball coming across the plate. Each pitch was also measured by a fixed-receiver remote Pocket Radar unit for a second measurement of the velocity.

What we found was the Triple-A balls did seem to register higher velocities. Over a span of 38 pitches with the Triple-A/MLB balls and 38 pitches with the traditional MiLB ball, the Triple-A ball averaged 92.4 mph while the MiLB ball averaged 91.86 mph. The Triple-A ball also had less horizontal and vertical break.

But there was enough variance in how the ball came out of the pitching machine (our fastest pitch was 97 mph and our slowest was 89) that we could not state confidently that our findings were because of anything more than random chance. A paired T-test (a statistical test to see if an experiment with a single variable finds a statistically significant result) found a result of .20. A result of .05 or less would have indicated statistical significance.

So in other words, we couldn’t say we found anything significant.


We attempted the experiment with a much larger sample. This time, what we really discovered was that these baseballs are not designed to be repeatedly fired from a three-wheeled pitching machine at high velocities. 

In our second test, the MiLB ball recorded higher velocities than the MLB/Triple-A ball. It may be that our hypothesis was simply incorrect. It may have been random chance with no statistical significance. But the result may have also flipped because the MiLB ball seemed to handle extreme use better than the MLB/Triple-A ball. The leather on the Triple-A ball became much rougher after multiple trips through the three-wheel pitching machine while the MiLB ball remained relatively smooth and consistent with its original condition. Considering that MLB balls are quickly thrown out of the game at the first sign of significant wear, durability is not a consideration in the performance of the ball in real-life conditions.

Do the new Triple-A balls help pitchers throw harder? We tried to find out, but unfortunately, we still do not know.

In science and baseball, you win some and you lose some.

Thanks to Baseball Rebellion’s Chas Pippitt, Dave Shinskie, Tyler Zupcic and Spencer Smith for their assistance with the experiment.

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