The ball goes into the post. The two players above him on that side of the floor then screen for each other and cut. Whoever is open gets a handoff or a pass back out, and whoever is not has still pulled a defender away from the post.
Why coaches use it
A post entry on its own is a two-on-two at best, because the moment the ball goes inside two more defenders start to dig at it. The split gives the post something to look at while he works and gives those diggers somebody to worry about.
The rule of thumb is old and still right: pass to the post, screen for the man above you, then open up to the ball. Both cutters end up facing the passer, so the post always has a target if the double comes.
It is also the cheapest way to make a switch cost something. If the two splitters are a guard and a big, any switch on the split leaves the post one-on-one in the middle of an empty lane, which is exactly where you wanted him.
How it is guarded
- Switch the split. Easiest answer, and the one that hands the post his matchup. Make the switch happen between two very different players on purpose.
- Stay attached and fight through. Correct and hard, and it is why the second cutter is usually the one who scores.
- Dig from the corner. A defender leaves the corner shooter to swipe at the post. That is the read: kick it out before the dig recovers.
Space the weak side wide. If two of your players are standing on the other block watching, the split does nothing and the post is guarded by four.