His grip and hand action is what causes the pitch to decrease in velocity .
As with any pitch , deception is key -- arm speed must stay as high as possible , which means the pitcher must throw it as hard as he can .
pitcher 's grip and hand action is what causes the pitch to decrease in velocity .
As with any pitch , deception is key -- arm speed must stay as high as possible , which means the pitcher must throw it as hard as he can .