Two Fundamental Topics on the Baseball Swing

For eons hitting coaches have focused on mechanics, bat position, elbow position, among other topics related to hitting. As technology has weaved its way into many aspects of the game, it’s now apparent that there are two fundamental topics on baseball swing that are essential in developing a player’s ultimate potential at the plate:

    1. Bat Speed and Acceleration (Power)
    2. Being on plane w/the ball

The first attribute is trained outside the nets, while the other is done inside, and each has many components. It might sound simple, but it isn’t. Delivering on these two topics requires extensive knowledge and execution across a broad spectrum of disciplines, from exercise science, to bio-mechanics to hitting mechanics, and the ability to parse through data, analyze it and prepare a very specific game plan for each athlete.  So, let’s cover all this in some depth.

1. Bat Speed and Acceleration (Power)

Everyone knows hard contact is important. Exit velocity (EV) has become a hot topic. But, here we’re talking about bat speed (the precursor to EV).  It’s important to understand what drives it and how it’s created because it is a function of two different but related topics, including:

    • Power and Explosiveness
    • Kinematic Sequence

Remove either of these two attributes from the player and you’re leaving potential on the table.

A. Power and Explosiveness – How do we create POWER and EXPLOSIVENESS?  It involves 2 different elements:

    • Mobility / Stability
    • Power

Mobility / Stability – You can’t do much without mobility and stability in all the right places for very long and that definitely goes for explosive movements like hitting. Stability, which is often thrown in together with mobility is the ability to maintain or control joint-movement and/or position.  It is achieved by coordinating the actions of surrounding tissues, the neuromuscular system and getting stronger in the weight room. Here is a summary of the many components that go into attaining optimal mobility / stability at the plate:

    • Back Hip Mobility – Back hip IR is paramount for getting full rotation during the loading phase without creating a “negative move” away from the pitcher.
    • Ankle Mobility – Without proper ankle mobility, a player can find it difficult to maintain a stable foundation from the back leg, or a stable base of support at heel plant to swing from.
    • Oblique, Rib-cage and T-spine Mobility – Limitations in either boney, fascial or tissue restrictions can make it difficult to achieve adequate hip/shoulder separation which allows the upper body a strong stable support system to rotate from. It’s also THE major player for transfer of power up the kinetic chain.
    • Leg Strength and Power/Stability – This gives the athlete the ability to laterally stabilize both the front and back sides helping to both create and transfer ground reaction forces from the ground to the bat. Without it, the torso will go early, possibly preventing a proper kinematic sequence (discussed further below).
    • Shoulder Mobility/Stability – Shoulder limitations can have a negative effect on lower body stability and ultimately bat path.
    • Core Stability – Other than being the center of everything, a strong core also has a positive effect on the body’s ability to rotate and re-coil.
    • Forearm /Wrist Mobility – This is crucial in order to allow to set and release properly. It also allows for hitters to adjust later in their swing.
    • Scapular Mobility – Limitations in back side scapular mobility can prohibit good separation of the hands from the body. Scapular retraction also plays a major role in hip/shoulder separation.

Power – While everyone is focused on strength, it’s important to note that strength without explosiveness is the wrong kind of strength for baseball players. We’re not talking about the Olympic lifting type of strength. We’re talking about explosive strength or the ability to create force quickly over a short distance.  When it comes to making hard contact it all comes down to basic physics and the body’s ability to create maximum power:

Force = Mass * Acceleration

Power = Force * Velocity

Power = Mass * Acceleration * Velocity

Said differently, EXPLOSIVENESS is about Power as defined above. In this case you can think of:

    • Mass as the weight of the bat
    • Acceleration as the rate of change in Velocity of the bat at the point of contact between the bat and the baseball.
    • Velocity as bat speed at the point of contact

The good news is that all of this can be measured and improved with the right type of training.

So, how do we do it? As mentioned earlier, developing strength, speed and explosiveness in athletes is purely physics. Applying these traits to basic anatomical attributes can get a bit complicated but at the end of the day it’s all about the relationship between Force, Velocity and Power.

Traditional strength training increases our ability to apply a maximum amount of force which takes care of force and distance. But for power to be maximized the time component must also be optimized. This is the aim of training for power – to reduce the amount of time it takes to apply a set amount of force over a specific distance. This involves understanding the interaction between force and velocity and their influences on prescribing exercise selection and specific strength zones. This is VITAL for any strength and conditioning coach seeking to optimize peak power production in their athletes.  Here is a chart explaining different training zones and associated parameters:


One advantage to using these training zones and monitoring their associated bar and body velocities is to hone in on the trait the athlete is trying to develop to help improve performance at their specific sport. Every zone is associated with a specific bar speed (velocity) and thus produces a different stimulus and corresponding performance adaptations that are proprietary to the zone itself. This is where VBT comes in.

Velocity-Based Training (VBT) is a training method in which bar speed is monitored via a Tendo unit or a linear transducer such as the PUSH Band that we have been using here at RPP with great success. These devices help an athlete target and train in these specific strength zones more precisely to help better create the specific training adaptation we/they are chasing.


To sum it up, we can optimize power production better and quicker by knowing where our athletes are on the force -velocity curve through testing and then utilize VBT to pinpoint the special strength zones as well as using external cuing to get better “buy-in” from the athlete. All in all, it’s all about giving each individual athlete what they need.  You can click here for an extensive article on training with VBT.

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B. Kinematic Sequencing – Not all throwing motions are created equal. Some guys rely more on strength, some guys elasticity (facial tissue) and some are simply genetic “outliers”. But close analysis, in not only numerous studies but also from our own experience at the facility with our K-Motion sensors reveals that there is one common denominator among power hitters, a proper sequence up the kinetic chain.

This pattern is referred to as the “Kinematic Sequence” and can be only viewed through motion capture sensors that we place on the athlete’s body during the swing. The sensors measure angular velocities up the kinetic chain demonstrating when each part decelerates and the next accelerates.

Players can be out of sequence which leads to inefficiencies and lower bat speed. Motion capture technology allows you to measure all these movements along the kinetic chain and even hone-in on areas that can be improved during training to bring about a higher level of kinetic chain efficiency.  Net Result of all this is as follows:

It shouldn’t be a surprise that power generation improves as you move up the ranks.  Below is a summary of several metrics relating to power generation from high school all the way to the pros, as provided by sensor company Blast Motion:

(Courtesy of Blast Motion)

2. Being on Plane w/the Ball

A lot has been written on this topic but it’s important to highlight the value of being on plane with the ball, and doing so for as long as possible. It’s not rocket science. The pitched ball has a downward descent angle and if you want to improve the likelihood of a solid hard contact you’d want to be on plane with that pitch for as long as possible.

From the moment the baseball is released by the pitcher to the moment it’s hit, a 90-95 mph pitch takes approximately 400 ms to reach the batter. If you zero in on the actual point of contact, it’s a fraction of that. We are talking about 7 ms, that’s 7 thousandths of a second! The whole thing happens way too fast for the human eye. Luckily, with use of technology your swing plane can be measured with what’s referred to as the Attack Angle.

Many confuse the term Launch Angle and Attack Angle. They are not same (click here). Attack Angle is the angle of the bat’s path, at impact, relative to the horizontal. In order to stay on plane with the ball for as long as possible and given the downward descent of the pitch, you will want an upward path for the bat, or a positive Attack Angle:

There are numerous sources highlighting the benefits of a positive Attack Angle (AA). However, late last year we did our own internal study, where we collected data from several player’s batted balls into 5 categories:

    • AA < 0 degrees
    • 0 =< AA < 5
    • 5 =< AA < 10
    • 10 =< AA < 15
    • AA >= 15

We then evaluated the outcomes using a metric we call “Well Hit Balls” (WH Balls), defined as follows:

    • Balls hit at 90% or better of Peak Exit Velo
    • Launch Angle > 6 degrees (Rapsodo definition for a min. low line drive)
    • Launch Angle < 24 degrees (Rapsodo definition for a max. high line drive)

The chart below provides a spread by “% of WH Balls” at different ranges of Attack Angles. As an example, in the first column below, approximately 25% of balls hit with AA < 0 were WH Balls. Similarly, with Attack Angle between 10 and 15, nearly 40% of balls were WH Balls. Even though limited in scope with only 500 data points, the chart does show a bell curve peaking between 5-15 degrees.

Blast Motion, with access to a much larger data set than ours, summarizes ideal ranges for different levels of play as follows:

Averages are helpful.  However, it is our internal conclusion that even though “Average” Attack Angles may direction-ally represent the swing plane of a player, the standard deviation says you would need to look beyond the average. Consequently, we look at ranges vs. averages to get a better sense of a player’s swing path. For example, a player with a 5-degree average AA might have a range of -5 to +10 degrees.  A positive 5-degree AA may sound ok, but not if the low end of the range is -5 degrees and the players spends most of his time below a zero AA, with a few outliers above it.  You must look at the range.

An incoming fastball generally has a downward descent angle in the mid- to high-single digits (obviously a curve ball would be higher).  It is our general belief that your swing plane must be, at the very least, level with the ground (a zero degree AA) and up to as high as 15 degrees on the upper end of the range.

Hitting is about many things.  It’s hard to do well and do it consistently.  But you can put yourself in a better position to succeed by getting more explosive to improve your bat speed and being on plane with the incoming pitch descent-angle for as long as possible to optimize timing and contact.

By Bahram Shirazi (BSEE, MBA) and Nunzio Signore (BA, CSCS, CPT, NASM, FMS)

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