The Myth of the Pendulum: Insights into Barrel Acceleration in Baseball Swings
By Ken Cherryhomes
Barrel Acceleration: In this series of frames, we can observe the acceleration of Yordan Alveraz’s swing along three common points of contact: Outside, middle, and inside. To qualitatively assess the rate of barrel acceleration, we must first establish a fixed point from which to measure from. That point is the front edge of home plate, in this scenario.
The first collision point is the outside point of contact for this swing’s arc, which is approximately 8-1/2” behind the front edge of the plate. The barrel’s final velocity at this point of impact was 75.7mph.
From there, the barrel arcs to the middle position, where the barrel is parallel or equal to the batter’s hands, directly above the front edge of home plate. Here the barrel’s final velocity was measured at 85.1mph, an increase of 9.4mph over 8-1/2”.
Finally, we arrive at the point of contact which is 12” in front of the front edge of home plate, where the final barrel velocity was measured at 94.1mph, an increase of 9mph over a distance of 12”.
Contrary to the common beliefs among many baseball experts that maximum barrel velocity is achieved at the point where the bat’s arc levels with the hands, the barrel’s sweet spot directed toward centerfield—akin to the apex of a pendulum’s swing—data from this swing shows the barrel continues to accelerate even after passing this point. This suggests that the rate of acceleration, while diminishing, does not halt or reverse immediately. The barrel velocity increases beyond the parallel point, indicating that the bat’s swing dynamics allow for continued acceleration beyond the hands, challenging the conventional understanding of when peak velocity occurs in a baseball swing.
Empirical evidence from baseball statistics aligns with this assertion in that the hardest-hit balls and the longest home runs are pulled ones. Now, thanks to the Hawkeye system, we have more data to support this.
Deceleration Misconception: The common misconception is that once the bat is no longer being actively accelerated (when it’s equal to the hands), it must be decelerating due to gravity and air resistance. However, what’s crucial to understand is that deceleration isn’t immediate. The bat, having mass and momentum, will continue to travel forward at an almost constant speed for a brief moment, even potentially accelerating slightly if the batter is still applying force, albeit less effectively.
When the bat passes the hands, the direction of force changes. Instead of the hands pulling the bat forward, they start to resist the forward motion of the bat.