All that is necessary to create lift is to turn a flow of air.
The airfoil of a wing turns a flow, but so does a spinning
baseball. The details of how the force is generated are fairly
complex, but the magnitude of the force F depends on the radius
of the ball b, the spin of the ball s, the velocity V of the
pitch, the density r of the air, and an experimentally
determined lift coefficient Cl. F = Cl * 4 /3 * (4 * pi^2 * r *
s * V * b^3) where pi is the number 3.14159 .. the ratio of the
circumference to the diameter of a circle. As the force acts on
the ball, it is deflected along its flight path. If we neglect
the viscous forces on the ball, which slow it down and change
the magnitude and direction of the force, we have a constant
force always acting perpendicular (at a right angle) to the flow
direction. The resulting is a circular arc. On the figure, we
see the trajectory of the baseball as it moves from the pitching
mound to the plate from right to left. Each white dot is the
location of the ball at .05