Dating back to the 17th century, the science behind a baseball’s movement can be attributed to the natural laws determined by Sir Isaac Newton.
An object in motion, as stated in Newton’s first law, will continue its movement in the same direction, provided an external force doesn’t counteract it. By the same token, an object that’s standing still won’t move unless there’s an impeding external force. For baseball purposes, a baseball won’t budge its position until a pitch propels it. Once the ball is live, it will continue on its path at the same speed until a force–be it gravity, friction, or the connection of a bat–alters it.
Newton’s first law, though, can quickly become confounding in relation to the sport of baseball. Gravity’s force invariably pulls downwardly on the ball–it also creates the arc as the ball leaves the ballpark. A force known as drag takes place once the pitcher releases the ball, causing it to slow down. This friction is a byproduct from air thrusting against the moving ball.
The fraction of a second when the ball and bat collide registers either success or failure for a hitter. The batter wants to make sure that the head of the bat gets to the right place at the right time, with as fast a bat speed as possible. The outcome of the baseball is largely predicated by how fast the bat moves at the precise moment of the striking contact. This instance perpetuates energy.
The moving baseball and the swinging bat both contribute energy to the collision. While they each are going in different directions, the ball has to end up in a full stop before roving again in the adverse route, when the bat clashes with it. The energy winds up in two places: transferred from the bat to the ball and increasingly more functions to stop the ball’s movement. Some of this energy that compresses the ball turns into heat. Such energy cannot be manufactured or dispelled; it’s all one in the same before or after the collision taking form.
Momentum, too, is another quantity that’s evident in this baseball scenario. This matter denotes the moving subject as it pertains to speed, mass, and direction. It’s the total momentum of the respective entities that has to be equivalent preceding and after said collision. The conservation of momentum for the batter can be translated insofar as the faster the pitch and swing–despite its difficulty–the farther the ball will go, or vice versa for the inverse.
In the 21st century, consequently, the hitter’s swing and bat utilized remains a physics problem, one in which Diamond Kinetics, another Pittsburgh-based startup, dissects in order to solve it.
The baseball swing, at its core, is the interplay between a player and the bat. The player performs the force to the bat that makes it maneuver at the desired time and place.
Dr. William Clark, Founder of Diamond Kinetics, mentions to SportTechie that although the physics angle isn’t immediately thought of when a player swings the bat, the mathematics used to analyze swing motions are virtually identical to a “robotic paint sprayer” or “carnival ride”–forces are applied to move items at certain speeds. Hitting, however, is different due to each player being distinctive to one another. Of course, every baseball player’s physique is slightly different in size and physical ability.
Correspondingly, the instance of a ball affecting the bat is a physics problem. Hitting the ball with a heavier bat at a higher speed, for the most part, will make it go faster and further. At the same time, though, not every batter can swing a heavy bat at the same speed, declining speed once the bat proves to be too heavy. Searching for the optimal bat inclines to be a physics issue, especially since each user has their respective bat weight and weight distribution that’s tailored to handle what they can.
There’s inevitable trade-offs to keep in mind, with respects to finding the right bat: swinging early once the pitch is recognized, swinging the bat for improving chances to make good contact, and swinging bat to direct the ball to preferred orientation.
The education to enhance a bat swing for performance stands as a physics problem that can be explained with data via Diamond Kinetics’ SwingTracker sensor product that mounts on the knob of a bat.
The actual motion of the bat, prior to and after the swing, represents the initial measurement that leads to what’s beneficial for baseball players. Dr. Clark explains that inertial sensors quantify acceleration and angular rotation rates of the bat, where a series of computations are processed to reconstruct the bat motion. Thousands upon thousands of pieces of information are involved to reveal the complete path of the bat, which is showcased as a 3D rendering for players and coaches to analyze. Several of the features that diagnose the swings can also be presented numerically, like how far the bat moves away from the body and the bat’s upward or downward strike right before its impact with the ball.
“From a training perspective, this is important because how one’s performance is changing with practice is more important than any single swing’s metrics,” says Dr. Clark, with regards to trends within these numbers being trackable.
To synthesize these physics equations to make sense to users, that’s a real challenge and an ongoing education process for Diamond Kinetics. Their approach is to provide high-level summary data along with the specific metrics that coaches tell them are important. It’s an open dialogue, where anything can be taught lucidly–from simple analogies to actual equations that the youngest player can comprehend to the analytical pro, respectively
While everything starts with the sensors, there’s an entire hardware and software system that unifies the information that players receive.
Inside the sensor, a circuit board houses the sensors, Bluetooth, and the microcontroller that runs it all, in addition to the battery and charging hardware. The firmware is written to operate the product appropriately–primarily to continually monitor the sensors, identify swings, and push the data the mobile device. The mobile platform functions in a sense like a middle-man; given that it receives data from the sensor, computes swing information from data for the user’s display, and delivers it to the cloud for storage and more in-depth analysis. And the web app serves as a secondary interface for users to access all of their data and connect with others.
“Ideally, to measure the motion of a bat we could directly measure the positions of all of its points as it moves,” Dr. Clark states for SwingTracker’s intended functionality.
“Actually, since it is a solid body, we need to know only six pieces of information–its three locations in space and its three angular orientations–at each instant in time during the swing. There are no practical sensors to do that effectively in a batting cage or on field, however, so inertial sensors are used,” continued Dr. Clark.
The algorithms in the sensor are used to spot when a swing happens, then transferring the data to the mobile device. It’s worth noting that the swing calculation algorithms don’t actually live inside the sensor whatsoever–they’re in their proprietary physics engine within the accompanying app. The sensors, thus, work as a data collection and transmission module. Diamond Kinetics knows it collects the right data because it collects “ALL” the data–more than 11,000 data points per second, to be exact. It’s the physics engine that changes the raw data to discernible swing metrics.
Accordingly, the SwingTracker measures 15 different aspects of a swing, 11 of which are more granular metrics for the four summary components: Speed, Power, Quickness, and Control. The numbers under each of the summary components delineate its respective score calculation.
Jeffrey Schuldt, Diamond Kinetics’ Chief Commercial Officer, explains the key takeaways the user should get from these analytics: “The swing is a very complex set of movements. There are both complementary relationships and trade-offs between the summary components. For instance, Speed is directly related to Power. As a player increases the Speed of their swing, they will typically see an increase in Power. Conversely, if a player is focused entirely on Power, they may sacrifice Control.”
Power–in it by itself–proves to arguably be the most complicated to understand, yet the lone statistic that’s coveted but not covered by other sensors out there. So, Diamond Kinetics breaks down its three pertinent metrics in SwingTracker with an analogy of a sports car and a dump truck.
The Average Swing Power is equivalent to the “horsepower in the engine of a sports car or dump truck.” Max Acceleration means “both a sports car and a dump truck can use the horsepower to move from 0-60 MPH, a sports car can do it more quickly.” And Impact Momentum suggests “once the sports car and the dump truck are each going 60 MPH, which one do you want to be driving if you are going to run into a brick wall?”
By expressing these numbers in this fashion, they hope it gets the point across to users and teaches a couple core tenets of science and physics. Dr. Clark asserts that the ability to generate power in the swing is “really, really important.” The degree in which the ball is hit and distance traveled are a function of the transfer of energy from the bat to the ball at collision. Power serves as a gauge of the build-up of that energy.
While part of Diamond Kinetics’ core values is to enable user’s performance improvement through precision and accuracy–finding it instrumental to integrate power and its facets to this system–however, “if we can slip a little STEM education in along the way–all the better,” exclaims Schuldt.
Baseball players just have to interpret their respective swing data two-fold: comparing metrics versus fellow peers as well as monitoring their own trends over time.
On top of that, users have the ability pair video with data–somewhat similar to action sports tracker Trace–in SwingTracker. Someone else, though, has to use the smartphone to click the video button and then record it during the hitting session. The app will instantly stop the video after the swing, synchronize the metrics to the video, and attaching it to the swing, with a small icon for reference later. This feature is critical since a swing, in effect, starts with, and mostly driven by, body movement and the kinematic cycle. It’s important to know what the hands and bat are doing, but users need to see how the entire body reacts and how that translates into the hand and bat motion for clearer inspection of the swing.
Up to this point, Diamond Kinetics has managed to secure $1.1 million in funding from private parties and fellow Pittsburgh-based Innovation Works. They’re in the early stages of tapping into complementary technologies that would allow them to interconnect the output from the physics of a pitcher’s throw with SwingTracker’s data, where quantifying motion in baseball becomes that much more comprehensive. Also, building up the user base for their DiamondCLUB online community for players and coaches to cross-reference, create custom sets of data, and data visualization examples.
Diamond Kinetics, therefore, is determined to defy the fundamental natural laws that science compacts with a hitting a baseball, powering the sport’s offensive production forward through physics.
“We are an ‘inch wide, mile deep’ in baseball, just like the players and coaches we serve,” states Schuldt.