Softball Pitching – The 4 Forces of Flying

By Clayton W. Souders, Jr., Pitching Coach
Lehigh University

I started flying when I was 14 years old. It always fascinated me how an object, like a plane, could defy gravity. I also love the thrill of leaving the planet and returning when and where I desire. The forces that keep the plane airborne are the same forces that keep the ball in flight.

Thrust

The plane’s propeller takes a large mass of air and accelerates it rearward, resulting in the equal and opposite reaction of the plane moving forward. When pitching “thrust” is a force and when you exert a force against a smaller object it moves. Pitching force is wrist snap, arm whip, and trunk rotation.

Lift

As explained by Bernolli’s theorem – the faster a fluid moves past an object the less sidewise pressure is exerted on the body by the fluid. The fluid in this case is air and the body is the ball. With a plane the wing creates lift as the air passes over it. With the ball, the raised seams and their motion create lift. “More rotation – More Lift.”

Drag

Anytime a body is moved through a liquid, such as air, drag is produced. Drag acts parallel to, and in the same direction as, the relative wind. There are 2 types of drag. Parasite drag and induced drag. The plane wings, fuselage, landing gear, etc. cause parasite drag. When pitching, the ball surface causes parasite drag. Induced drag results from lift being produced.

Weight

Gravity always acts “downward”, toward the center of the earth. If a plane engine fails, the plane comes down. When pitching, the quick forward rotation of the ball (drop) will cause the ball to come down.

Now that we understand the four forces we can realize why wrist snap is so important. If a pitcher wants good movement on a particular pitch she must create as much rotation in that direction as possible. The faster the rotation, the more movement. To accomplish this rotation the pitchers grip is all important. Each pitcher may find a grip that works for her, but be assured, each pitcher is using the seams as a snap-off point. Some pitchers prefer a 4 seam rotation while others prefer a 2 seam rotation. I believe the more seams the more “lift”.

The “thrust” of course is relevant to the speed the pitcher can throw the ball (m.p.h.). Arm whip and trunk rotation (the closing force) are the important factors here. The push-off is very important, however after many years of studying pitching I believe resistance (throwing against the stride leg), will create more “thrust”. When we combine “thrust and lift” to its maximum, we now have a ball that moves. (Rise, Drop, Inshoot, Outshoot).

Generally speaking, a pitcher that has trained properly for strength, agility, and endurance will be more successful than the pitcher who has not. This is where “drag and weight” come into play. In the late innings drag and weight cause the less conditioned pitcher to fatigue resulting in less movement and slower ball speed. This of course allows the ball to be hit more easily.

Fastpitch will always be a disease for me, but my favorite saying is: WILL FLY ANYTIME – WITH OR WITHOUT A PLANE!