Hello everyone. This is my first post here on the forum. I saw this challenge and decided to give it a shot. I think it's a really good challenge that seems simple but in reality can be a bit difficult to accomplish. I think I came up with a really good way to do it that is simple and quick. Hope you all like it. After a few attempts, I realized that the curve around the ball has a certain symmetry to it and can be divided into 8 equal parts. My process is based on that idea. Here we go!

First I made a sphere, and erased all but 1/8 of it. I made that section into a component. I then copied and flipped that component to reassemble the sphere. Next, I rotated 1/2 of the sphere 90 degrees.

I then opened one of the components and drew the curved line freehand on the surface. I began at the point marked with the red dot. This point is the center point of this arc.

After tweaking the line by eye to make sure it flowed smoothly around the ball, I offset the line twice on each side. I attempted to use the "offset on surface" plugin, but it produced unfavorable results, so again I did this freehand.

At this point, I exploded all of the components and smoothed the lines where they connected.

After scaling the recessed white line a bit to add some dimension, I continued to add materials and soften all remaining edges.