I guess you want a mathematical answer. I also have to guess or try to remember what a baseball bat resembles mathematically, since I don't possess one.
You can check out if what I say applies to your bat.
I believe it has a circular cross-section. The longer part I think is cone shaped and the end is hemispherical, half a sphere.
In terms of mathematical functions, a cone is a straight line rotated in 3 dimensions. The straight line passes through the origin (0,0) and has a steep slope.
The spherical part is the result of spinning a circle about an axis. The cone at its base has the same radius as the hemisphere.
Does that sound about right?
When the bat strikes the ball they come into contact at a single point, because both have round surfaces, so that the forces are concentrated at a point.
I hope this helps.