There are three variations of the baseline runner zone offence - high-low posts, double low posts, and double high posts.
a) High-low posts
3 runs the baseline on the pass to 1, 4 moves up to the wing for a pass from 1 (5 will stay inside).
5 can screen in for a skip pass to shooter 2.
On a pass to 3 in the corner, 4 cuts to the ballside low post, 1 and 2 rotate behind.
On a pass out of the corner, 5 flashes to the ballside high post and 4 goes to the weakside low post (post rotation).
Iowa continuity on ball reversal (there is no post rotation on the pass out of the corner).
b) Double low posts
On ball reversal both posts stay low and screen for the baseline runner, who can cut up the middle of the lane.
See Zone offence - Dave Odom rover.
c) Double high posts
There is always a double high post when the ball is at the point. Ball reversal can be by pass to the high post (shown), or using a high-post ballscreen. 5 dives to the middle on the pass to 4.
4 passes to 3 and dives low.
3 runs the baseline on a pass to 2, 4 comes high.
2 reverses the ball using 4's ballscreen, 4 and 5 go low.