A good defensive stance allows you to react in any of the four directions: left, right, forward or backward. You should keep your knees bent and feet about shoulder-width apart from each other. One foot should be a little in front of the other.
Do not reach in to steal the ball. Reaching in is not a good way to play defense, because it can make you get beaten on a ball fake, put you off-balance and force your teammates to leave their players to help. Just partially raise your arms out in front of you to be prepared for the ball if your opponent miss handles it.
How to pressure
One of the best ways to contain your opponent is leading him to dribble with his weak hand. For example, say he is a right-handed, you have to put your left foot forward and close in aggressively, so you can pressure him to dribble with his left hand or change his direction. Keep your head below your opponent’s, preferably level with his chest.
How near should you be to your opponent? It all depends on the time left, the score, the d your team is trying to play and whether or not your opponent is quicker than you.
Head start wins
If you are guarding a player who does not have the ball, it does not mean you can slack off. If he is a good player, he is thinking about getting into a better position to catch a pass. So get a head start and try to guess what his next move will be.
To score, your opponent will need two things: the ball and in good position. It’s your job to keep your eye on both. If the ball is over on the right side your opponent probably wants to cut from the left into the middle, go ahead and get a third of the way between him and the ball. Be faster than he is and frustrate him. Use your size and strength to block his way. Keep your hand closest to the ball outstretched.
Keep your foot closest to the ball in the passing lane that you think a potential pass would go. If there is multiple spots open to cut try to defend the spot with the better shot first.
How to defend an inside player
If shot blocking as a defender down low is your biggest priority you may find yourself on the bench with multiple fouls. You need position first. Get to the low position before your offensive opponent and do not let him post up or back in where he wants to. If your inside opponent is bigger than you, you should play in front of him. Be a royal pain in the butt to him and the passers. Make it very hard for them to pass it in low. If the opponent is smaller than you play behind him.