First of all, we should be vigilant. Know where the ball is and where the ball is. Usually, you have to cover a person's ball and stay away from him. B research opponents. Before you start blocking shots, make sure he will make a shot. Be patient. Don't leave your defender for too long, or he will shoot like nobody's business.
Second, the timing should be right. Card your action time and get close to him before he moves. Get in place quickly. Rush to the shooter or the position where he wants to shoot. Identify the lens. The key is to know how he can shoot, and his position and body movements will show his shooting type.
Third, A gets up quickly. You don't have time to jump with your knees bent. You must take off quickly with your feet. Stand up straight. Be careful not to foul because of physical contact or thugs. Unless he returns to the jumper, he will hit you because of inertia. C is fully expanded. If you stretch out your arm to catch the ball, you will reach higher. Take off the ball. Spin the ball quickly with your wrist, but not too much. Remember, a flick can change a ball that may be hit. It's better to take risks before he throws it.