On the jump ball circle, you don’t often hear about the importance of good blocking out, but it is crucial as well as very easy. Many times, it is obvious to both teams where the ball is going to be tapped. If one team has a much taller player jumping, he will tap to a pocket where he has two men together. However, often, even though the ball is tapped between the two, a smart player from the other team will cut in between and steal the tap. He can easily be blocked out since he has no time to fake and jockey at all, but it is necessary for the players on the circle to realize that he must be blocked out. This is a perfect example where technique means almost nothing. Getting the ball is simply a matter of realizing that an attempt to block out must be made.
In a second situation, on the free throw lane, many players merely step into the lane instead of stepping against the man beside them. To be sure you get the long rebound, you have to step against your man and clear out some space for the ball to fall into. Many players get good block out position, but the only ball they can get is one that is falling through the net.
From Dick’s book Stuff