Throwing a baseball in general with sound mechanics can be a difficult task. The function of the throwing motion requires the physical understanding of how potential kinetic energy moves through the body after ground reaction force or the lead landing foot is applied.
If too much tension happens when potential kinetic energy reaches a specific muscle out of sequence to the specific task of throwing you will create drag. In other words you can’t throw without the flow of energy from the ground and have it hit stiff muscles before that chain is linked up.
For example, the arm cannot be stiff prior to kinetic energy moving into that area or it won’t flow through the body to the next body part (the wrist and fingers) without being slowed down.
So, can we throw a baseball farther with or without a batting glove?
We first have to let the ball get all the way to the finger tips to get the most out of the exchange of energy from fingertips to ball.
Having said that, the next thing we have to consider is the freeing of energy into the ball from the release point. My first initial reaction to this question is NO, you cannot throw a baseball further simply because the glove acts like a small parachute for the hand.
The batting glove simply adds more drag on the hand which decelerates the hand before reaching maximum velocity.
Now, we have to add one more element - grip. Adding grip to the equation adds some hesitation. If the batting glove allows for a better grip then we may get a higher spin rate which can result in high velocities if relative hand speed is achieved.
As long as the fingers have some moisture on them, without being too dry and slick, getting the most out of that exchange of energy should afford you maximum velocity without a batting glove. Moisture can be a misleading term so let’s clarify. Moisture isn’t visible to the eye - you won’t see water or sweat.
Those two things will hinder grip. Making a fist and breathing air fast through the small hole of your fist will heat up the air in your hand. It will add the necessary moisture to maximize your grip.
You will find baseball players all over the country breathing into their hands on those early morning cooler games to keep the hands warm and ready to go. Or at times you’ll see pitchers lick the fingers and wipe off the visible moisture.
Some youth kids will wear their batting gloves to help maintain grip. I think this answer depends on multiple factors that varies with each individual player.