Arm Slots and the Pitcher's Grip

The human body can add a ton of variables to pitching. Sometimes our actions are exactly what we want, sometimes less so. And even sometimes we’re getting results out of shear dumb-doda-luck!

In any event, the following is to suggest thinking beyond the arm slot and the grips as independent agents and kind of think of them collectively add to or taking away some of your intended results.

You pick a pitch, grip the ball and deliver. Your visual witness says either the pitch is doing exactly what you want it to do, or, the pitch isn’t working at all, or sometimes the pitch works and other times it won’t.

What the heck is going on here?

Let’s take a look at few very simple grips, and what you witness the initial grip to look like in your hand prior to delivery, then what the arm slot can potentially do to that intended grip.

First, let’s look at the four seam fastball grip. Initially, in the hand your grip will probably look like this. Pretty standard stuff. You’d expect this pitch to go right where you want it with the greatest velocity that you can muster.

However, don’t be surprised if your arm slot delivers this pitch - which will give you a completely different report that what you’re expecting - 60feet away.
Something like this:

The two seam fastball is another pitch that might be giving you problems due to your arm slot. The two seam as shown below may look like this in your hand initially.


If you’re expecting this pitch to sink, or produce some other movement, you might be wondering why its not when your arm slot delivers this pitch. This delivery, by the way, can PLOW right through to swipe path of a bat. Gone!

The other pitch that might give you a problem is the slider. Initially, your slider grip might look like this:

However, your arm slot may produce this pitch as a delivery, hence, canceling out the slider’s signature approaching the plate. With this delivery, the ball tends to be slung from the hand, then flattens out during its flight to home plate. When that happens, the force from the release - fastball intensity, tends to have the seams orbiting the ball from side to side as appose to the desired spin of being elliptical.

However, some pitchers can actually make this work for them due to their releasing the ball far out in front of their stride knee.

So, take the time to experiment with different grips and what your arm slot does to that grip and its signature as it (ball) travels to the plate.

A video camera is a great asset here. Witness what’s happening and make your own judgements.
Coach B.

Good post, Coach B.

Pitchers really do have to become familiar with the specific movement on the ball that is generated by their individual arm-slot.

Spin on the ball gives rise to a small force (called the Magnus force) that moves the ball in the direction of the spin and at a right angle to the spin axis.

As you implied, arm-slot is what defines the orientation of the ball’s spin axis so there is an extremely important link between arm-angle or arm-slot at release and the character of movement you will get on your pitches.

This is only a problem for the pitcher if he doesn’t understand what kind of movement his arm-slot produces. If he does understand it, that would usually be more of a problem for the hitters. :lol: