A good defense is a mix of a pure willpower combined with some simple rules. I really can't do much about the motivation of your players but I can help you teach them how to play defense the right way.
We will start the drill by putting 2 attackers on the wings, and 2 defenders slightly below the elbows. One foot is in the paint. Point Guard will pass the first ball on one side and the defense will react.
The on ball defender will sprint to the ball handler, with the active arms in the air while lowering hips in the defensive stance. The goal is to cut of the MIDDLE of the court and to OPEN the baseline. The top foot of the defender should be above the top foot of the attacker. The help defender should go towards the middle of the paint.
Then, we have a cross court pass to the other wing, and we have the same defensive activity.
One of the most important things when we talk about the defensive positioning regarding the movement of the ball is: the player should start to move in the same moment as when the ball leaves the hands of a passer. If the player is starting to correct his position in time the attacker is receiving the ball - then it is too late.
For the final play, both attackers will get the ball and play 1 on 1 for the basket. Defense should try to get a stop, make contact with the lower body while being aggressive with the hands.
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