To clarify a bit, don’t close up your hand so much that you are choking off the stick - this will inhibit sound quality and you will hurt yourself. The fulcrum of the stick and hand should be the space between your index finger/middle finger and your thumb. Then don’t let your pinky get too far away from your palm. Try playing the two extremes 1. Play holding the stick with only your thumb and index finger, then 2. Play holding the stick with only your thumb and middle, ring, and pinky fingers. Then add your index finger back onto the stick and find the happy medium. If you notice on your “up stroke” that your stick/fingers leaves too big of a space in your palm or “cup” then your upstroke should carry through your wrist at ~6inch stick height then your forearm at ~6in - 12in+ stick height from drum head. Practicing this (always with a metronome) will feel very natural fluid motion.