Ball at top of key with coach or player, 2 wing players on court.
D1 plays 3/4 post defense, feet on either side of O4's, deny the easy pass to post.
Coach pass to wing, D1 now has to front the post on strong side.
D1 should take 1 big step over O4 and "sit" on his leg/knee.
As the ball is swung round 3pt line, D1 to should return to 3/4 post, then help defense.
As the ball is sung to oppisite wing, D1 should revert to help defensive stance.
Help defense should should see both ball and his man. the split line is use as a guide. never cross it if your man and ball ar on oppisite sides.
O3 should square up and then drive to basket forcing defender D1 to help, take charge.
Take charge, make sure your there early, plat feet, bent knee's.
You can either at this point rotate the defender or if the drive is stopped continue play, O3 dribbles back out and swings ball back round.
This gives the defender more time to practice the principles of post defense.