Position of Your Hands. Coaches always urge, “Hands up!” so their players will distract the offense and deflect passes, and players prefer to play with their hands at their sides. Because it is easier to move with hands at your side. (Sprinters don’t raise their hands until they cross the finish line.) In guarding the ball, there are times to play with hands down and times to play with a hand up.
If you are guarding a dribbler, your hands need not be up, they should be down faking at the ball or helping your body stay in good position, on balance. The important distinction regarding your hands comes when you are guarding a player who has the ball but has not yet dribbled. If that player is out of shooting range, your hands can be down at waist or knee level, one to the side and the other stretched out to the ball handler’s belt buckle. (The outstretched hand should be the same as whichever foot is forward. Left foot out, left hand out, and vice-versa.) The outstretched hand should be palm up, always prepared to slap up anytime the ball is held out in front.
If the player with the ball is in shooting range, you should have one hand up, almost touching your shoulder, poised to jab upward, so it is clear to the player with the ball that you are prepared to block his shot (though really all you want to do is distract him by getting your hand up near the ball and your arm in front of his face).
Never raise your body up to block the pass or shot of a player who has not yet dribbled. Stay low, keep your weight back, stay in that bubble and slap upward from the waist if he is out of shooting position, or shake your hand over your shoulder if he is in shooting position.