The How and Why of Differential Command Balls
In 2017, we made many strides at Driveline Baseball in an effort to further our ability to help athletes develop. If you follow our social media, you’ve seen that one of those ways was through implementing structured pitch design sessions with the use of Rapsodo and Edgertronic cameras. The other, less glamorous, way has been to improve command through use of our weighted and command balls. Though not as talked about on social media, the differential command balls have helped athletes, both at Driveline and schools around the country, make significant strides.
In an effort to explain some of the science behind them and help provide a bit of guidance to those struggling with command, let’s break down the science behind our command balls and how we structure programming with them to obtain the best results.
When you first pick up a set of command balls, you’ll notice something is immediately different about them from standard baseballs: some are larger and some are smaller, 5% larger and smaller to be exact. Also, some weigh 4-oz, some weigh 6-oz. We refer to this size and weight difference as “differential command training.”
This chaos of change in size and weight immediately leads people to exclaim, “Ahh! Training proprioception!” And yes, that’s likely a major contributor of why this system helps improve command. After all, proprioception is the ability to unconsciously perceive movement and orientation from stimuli within the body, as it relates to motion, position, and equilibrium, and that’s exactly what we’re looking to have athletes feel. We want athletes to feel and make adjustments based off the different weights and sizes. In theory, this should help improve an athlete’s ability to be more aware of where and how the ball is being released.
Research supports this theory. There are several studies examining training proprioception and its effects on skill acquisition. One such study examined proprioception training through balance and its effects on soccer skills. The study showed a significant increase in several of the skills and noted the importance of having both diverse and complementary proprioception training programs (Bekris et. al. 2012).
The keyword in that statement is in the necessity for a diverse program. As baseball players, we’ve thrown 5-oz baseballs with a 9-9.25 inch diameter for our entire careers. There’s no diversity in the implement, so eventually our ability to improve that skill diminishes because our bodies have adapted to it. In order to further grow, we have to make changes, and one way to do this is through the use differential command balls to help provide a proprioceptive change.
Contextual interference (CI) is the second and far less understood piece regarding the benefits of differential command balls. CI is a motor-skill acquisition theory claiming that by randomizing the motor skills you are trying to teach, you improve skill retention and transfer.
For example, a study by Hall et. al. looked at the effects of CI with hitting. This study examined if a blocked, random, or control group would have better success improving an athlete’s ability to hit three different pitches solidly. The pitches were curveball, fastball, and change-up. The random group saw 15 of each pitch in a random sequence with no pitch being repeated more than twice in a row. The block group faced 15 of each pitch all in succession, and the control group received regular BP only. The results found an improved ability for the randomized group’s performance compared to the other two groups.
However, the randomized group initially performed worse than the blocked group. This is because the initial increase in randomization results in poorer performance early in training, which is potentially even worse than baseline performance with the understanding that over time the transfer and skill retention will actually be higher. This, however, brings up the importance of data tracking and monitoring skill increases over time, as it is possible to over randomize for an athlete’s skill level. If this occurs, the athlete will likely not be able to adapt to the stimulus.
How to Put it Together
Throwing the command balls is difficult, but it’s important to understand the challenge. We start by testing an athlete’s command with a 5-oz baseball to establish a baseline and then begin slowly randomizing the program to allow time for the athlete to adapt. We start with our 4 and 6 ounce weighted balls and then move onto the differential command balls.
We also require athletes to have a certain percentage of pitches thrown for strikes twice at each stage of the process before advancing in difficulty. Initially, we don’t even mix in the over- and undersize balls because most athletes haven’t ever tried throwing strikes with them. This on its own is a significant amount of randomization.
As athletes progress, we begin increasing the randomization or individualize the program based on what the athlete’s response to the training is. For example, if an athlete constantly misses arm side, the program can be tailored to correct for this by working through an oversized and overload focus. The inverse is true for an athlete who has a tendency to cut and pull the ball across the zone, missing low and gloveside. Regardless, when implementing the program, it’s important to keep it simple initially and then build as an athlete’s command percentage at each stage of the program meets the measured objectives.
Bekris, E., Kahrimanis, G., Anagnostakos, K., Ioannis, G., Christos, P., Sotiropoulos, A.(2012). Proprioception and balance training can improve amateur soccer players’ technical skills. https://www.researchgate.net/profile/Evangelos_Bekris/publication/262117331_The_effect_of_a_balance_and_proprioception_training_program_on_amateur_basketball_players’_passing_skills/links/5645df0908aef646e6cd7804.pdf
Hall, K., Domingues, D., Cavazos, R. (1994). Contextual Interference Effects with Skilled Baseball Players. https://www.gwern.net/docs/spacedrepetition/1994-hall.pdf