Defending the Ball

...(略)

The defender whose offensive player is one pass away from the ball should be positioned between that player and the ball. The defender should also be slightly off of the offensive player. From this position, the defender decreases the offensive player’s quickness and gives himself more time to recover and contest the backdoor cut. The defender’s chest should face the offensive player, and his back foot should be positioned so that it cuts the offensive player in half. The defender’s front foot, outside arm, and hand should be in the passing lane.

Denied the ball this way, the offensive player is forced to go backdoor, where the help-side defense is positioned. This overplay position also allows the defense to continue to dictate and control the tempo of the game. But to do so, defenders must always see both the ball and their player while they are in the overplay position....(略)

Defending Two Passes Away

The defender whose offensive player is two passes away from the ball should have one foot in the foul lane. He should position himself to see both his player and the ball. This puts the defender in position to either stop the penetration on the ball side of the court or to react to the lob pass to his player.

Defending Three Passes Away

When a defender is guarding an offensive player who is three passes away from the ball, the defender should position himself in the lane. From this location, the defender is in the best possible spot to stop the ball-side drive.

http://www.humankinetics.com/products/showexcerpt.cfm?excerpt_id=3388

=====

Positioning Tips

...(略)
   6. If your man is one pass away, keep the hand closest to the ball in the passing lane. Do NOT let your man receive an easy pass. If the ball handler has an easy pass, he is never under any pressure. Do not lose sight of your man, ever.
   7. If your man is two passes away, keep one foot in the key. This will enable you to help if a teammate gets beat on a drive. Do not lose sight of your man.
   8. If your man is more than two passes away from the ball, put both feet in the key. Don't relax. As soon as the ball is passed, your man will no longer be 2 passes away!

http://www.akcoach.com/index.htm

=====

Deny Defense
If your man is one pass away, you should be in "deny", but not a complete dead-ball denial as seen at the bottom of this page. You should be a little up the line and a step or two toward the ball (see Diagrams A and B). This way, you are in position to steal the pass, and yet still be able to give help to the on-ball defender if the ball-handler tries to dribble-penetrate.
Helpside Defense
If your man is two passes away, you should be in "help-side". If the ball is above the free-throw line (Diagram A), the help-side defender should have one foot in the lane. If the ball is below the free throw line (Diagram B), the help-side defenders should be straddling the "help-side line".

http://www.coachesclipboard.net/DefenseShellDrill.html

---