Three-Quarter Delivery | Henken [Baseball Pitching Lab Japan]

The three-quarter delivery is considered the most natural pitching motion.
The term "quarter" means one-fourth, so "three-quarter" refers to three-fourths.
If lowering the arm toward the ground is considered 0 and raising it straight overhead toward the sky is considered 1, then the arm passes through approximately the three-quarter position.
In reality, the boundaries are not strict, and the range can vary widely from angles close to overhand to those closer to sidearm.
The three-quarter delivery makes effective use of centrifugal force, allowing pitchers to generate high velocity for reasons different from the overhand delivery.

Breaking Balls from a Three-Quarter Delivery

The three-quarter delivery is often considered the most natural way for a human to throw, resulting in relatively lower stress on the shoulder, elbow, and lower back.
Of course, even within the three-quarter category there are many variations, so it cannot be said that the stress is always low, but compared to other pitching deliveries, it is generally less demanding.
One important point to note is that when an overhand pitcher becomes fatigued and their arm slot drops, this is not the same as a true three-quarter delivery.
Unlike intentionally pitching from a three-quarter arm slot, this situation can be dangerous.
When the body continues to move as if throwing overhand while only the shoulder angle and elbow position drop, it creates excessive stress and can lead to serious injury.