I spiral wedge (kikumomi). The spiral aligns with the wheel's axis.
Think about what direction the flat clay platelets are tending to be aligned (flat sides) in the spiral wedging process...... what surface they are parallell to. Then think about what direction the platelets are aligned when you compress ( align actually) the walls.
That's why. Makes a difference.
If you are getting S cracking when throwing on the wheelhead .... it is other stuff causing it.
Off the hump S cracking is fixed by how you actually DO that process. There are some tricks... learned them in Japan....... listed them in other threads.
The 'center tall and then open' is a Korean/Japanese technique that I sometimes use. As is the 'pound open the cylinder before ever using water' one.