Baseball is so different than the other major sports in that when you try harder you often fail. Why? Because when kids get into a crucial game situation or just a regular youth game, they want to succeed so badly. When they hit, they grip the bat too tight, which slows down bat speed. Or, as a pitcher, you choke the ball, taking away the ball's movement and location.
Baseball is a relaxed-state game; the more relaxed you are the more you will achieve.
When you see major league hitters throw bats in the stands after swinging you know they have a light bat grip that promotes maximum bat speed.
We have a pitching ball drill where you walk behind pitchers that have their pitching hand down and try to knock the ball out of their hand. If we can't the pitcher is gripping the ball too hard and they choke their own velocity, movement, and location.
When you get into the heat of the game and want to throw the ball harder, lighten—don't tighten—your grip.
When coaches try to pump players up to improve their performance it often backfires because players try to do more than what they are capable of doing, and they fail to produce.
Teach relaxed concentration, not increasing players' adrenalin. We are teaching baseball, not football.