The offensive player will come from the opposite side of the lane to post up on the block on the ball side of the court.
To get around the defensive player the offensive player will lift their arm over and step around the defensive player.
Once the offensive player is in front they will have a very wide stance, showing a hand target where they want to receive the basketball.
This drill is to work on getting around a defender to establish post position on the block.
Good team defence is five players guarding the ball, not five separate one-on-ones. The shell drill is where that starts, so here is how to teach help-side positioning and rotations from the first week of the season.
Rebounding is the least glamorous thing in basketball and one of the most decisive. It is also almost entirely a habit, which means it is entirely coachable.
Good spacing is only the start. The best modern offences teach players to attack the defence's rotations and play in a permanent 4-on-3 - here is how to coach that read.