A good BLOB play can be simple yet complex at the same time. There can be very little movement by the players but those simple movements can create a lot of different actions. This is one of those plays. The movement is simple. 3rd and 4th graders can understand the movement and run this play. But the complex nature of the play makes it hard for the defense to guard the BLOB play.
The BLOB starts in a standard box setup. The shooter is on the backside elbow. The forward(3) is going to be the shooter in this play. The backside block will catch the in-bounds pass. The guard(2) is cutting up through the lane to the ballside wing. The point(1) and center(5) are both stepping into the middle of the lane to set a double screen to get the guard(2) open.
The point(1) must get down into the middle of the lane. The point(1) cannot stay up on the elbow. The 2nd action of the play requires the point(1) to move down into the middle of the lane. The guard(2) should wait until the point(1) gets to the middle of the lane before cutting out to the wing. This movement makes the 2nd action that much more effective.
After throwing the in-bounds pass, the big(4) steps into the block area. The point(1) and center(5) are standing in the middle of the lane. This sets up a triple screen for the forward(3) to run through going to the corner. The point(1) passes down to the forward(3) coming off the triple screen for the open corner 3-point shot.
This BLOB play does not have a lot of moving parts. It has the two backside players running an X stunt through the lane using the frontside players as screeners. Even though it does not have a lot of movement, the defense still will struggle having to run through double and triple screens. This is the type of BLOB plays that are simple yet effective. It is a good idea to have a couple of these plays in the playbook.