Ball Flight Dynamics

Your throwing motion creates the velocity and spin that determine how your ball moves through the air. After release, the flight of the ball is determined by gravity, lift and drag. Let’s discuss the effect of each force on your pitch.

The effect of gravity is the most familiar and is sometimes referred to as ballistic flight. When an object is thrown, it follows a ballistic path similar to the one in the picture below. In outer space without any gravity to change the flight of the ball, it would go straight over the head of the catcher. Since we do our pitching on earth, gravity causes the ball to fall towards the ground as it moves towards the pitcher. We can control this path to some extent with the speed of the pitch; the faster the throw, the flatter the curve.

 
F5 Image_Gravity_v_No_Gravity.crop.png
 

The drag force on a ball is very simple and, again, familiar. The resistance of the air causes the ball to slow down as it moves towards the catcher, as much as 12% of your speed is lost to drag, so if you throw a 70mph pitch, it may only be going 63 or 61mph when it gets to the catcher. This is one reason why radar guns are not consistent. The exact location of the pitch where a radar gun takes the measurement will vary, so even identical pitches will usually have slightly different readings on a radar gun. This is one of the strengths of the pitchLogic system: your speed is measured at the exact moment it leaves your hand, so the reading is always consistent with the pitch. Furthermore, the speed will typically read slightly higher than a radar gun because pitchLogic measures the speed before drag has taken noticeable effect on the speed of the ball.

The third force acting on the baseball pitch is lift, which causes the trajectory of a fastball to be flatter than ballistic flight and a curve ball to break. Consider how the wing of a plane uses lift to fly and maneuver. The direction of lift is perpendicular to the axis of the wing, so if the wing axis is horizontal, upward lift is created. If the plane banks to the left, the lift direction shifts accordingly, affecting the path of the plane.

 
F5 Image_Plane_Lift.3.png
 

In the same way, the Spin Direction determines the direction of the lift. Spin Direction is set by the backspin and sidespin components of the spin axis. Sidespin creates sideways lift, much like a plane banking to the left or right. Topspin creates downward lift, causing the ball to dive more quickly than it would with other types of spin. While the idea of downward lift may not seem to make sense, lift is a technical term used in aerodynamics. In this case, lift does not only mean force in an upward direction.

Once you grasp the basics of how to use spin to generate lift and ultimately the break you want, you can begin to practice pitching motions to create your desired spin. pitchLogic gives you an unprecedented understanding of whether you are achieving the spin, lift and break you want so that you can adjust your pitching motion until you do. 

Please be careful and recognize that improper technique or excessive repetition can cause injury. Follow your coach’s advice about how to practice controlling speed, spin and lift safely.