In my experience the opening and closing, especially in the WCWS, will depend on which pitch they are throwing. A RH screwball/riseball should have the pitchers hips the most open position, where as a curve ball, the pitcher will have a more closed (not always completely closed position).
The fastball is where this can get confusing. I am still torn as which way is best, as a has-been player and now a coach. There are benefits to both if taught correctly.
I personally learned to the stepping style fastball (closed style), and had some but little experience with the leap and drag (open style). By the time I got to college I had a weak screwball, but had a killer curve (which made me a suprise to teams in our conference) Everyone else was working on hitting the up and in pitches.
The fastball is where this can get confusing. I am still torn as which way is best, as a has-been player and now a coach. There are benefits to both if taught correctly.
I personally learned to the stepping style fastball (closed style), and had some but little experience with the leap and drag (open style). By the time I got to college I had a weak screwball, but had a killer curve (which made me a suprise to teams in our conference) Everyone else was working on hitting the up and in pitches.