Ball moving above the critical speed. Flow necessarily symmetrical.

The boundary layer now clings much further round the ball. The wake is now narrower, but the pressure in it immediately behind the ball is higher than in the first diagram, with the result that the retarding force (coefficient) is much less.

The boundary layer can also be extended in this way (for lower speeds) by slight surface roughness on the first half of the ball, and the resistance force similarly reduced.

(The drawing is not to scale : the thickness of the boundary layer is exaggerated in order to show it.)