Roundabout way of getting under 10k tris

[Zamattsu]

I first used the instructors method of applying the Surface Subdivision modifier and a bevel to add the white rings around the holes as shown in the video. However, the tri count was over 10k so I did some research and experimentation to figure out how to lower it.

I selected just the holes and split them off into a different mesh object, to maintain their detail, and I used the Decimate modifier on the rest of the ball to lower its tri count significantly.
I then joined the two separate objects back into one, deleted the wonky edges formed from varying levels of detail, and stiched the two together

The materials for the white rings got kinda weird when I filled in the triangular holes, but I thought it looked cool and went with it

[Miss_B]

Well that’s certainly a different look. I like it too, especially around the single hole for the thumb.

This gives the bowling ball a real “face”.

[NP5]

Nice work to the lower verts aim.
It has left a ‘flat’ cone ring round the finger hole as we can see via the reflected light.

Why lower the count? Low poly for a reason like a game use is fine. But low poly is not a ‘good’ on its own. The scene is unlikely to stress any machine unless making a huge amount more than the course directs.