I think that you may have not done this yourself or you would more easily understand.
If you go up in sequence, say 500 grit, then 1000 grit, then 2000 grit, then 4000 grit (using the available grit levels of Abralon), each succeedingly finer (higher numeric) pad would smooth out the rougher sanding lines created by the previous pad, which is numerically below it. So, in general, and if properly done, once you apply the 1000 grit pad, you would no longer see the 500 grit lines. Once you apply the 2000 grit pad over the 1000 grit lines, you would no longer see the 1000 grit lines. And so on.
However, if you apply a 500 grit pad, then apply a 4000 grit pad (as is done with balls like the Storm VG Nano), you would definitely see the 500 grit lines under the 4000 grit lines. In order to remove the 500 grit lines, you need to go through 4 or 5 4000 grit pads and sand for maybe 3- 5 minutes and even then, you might see be able to see them.
This situation, 500+ 4000 grit pads, vs the full sequence of 500 + 1000 + 2000 + 4000 grit pads, is a common differentiation in bowling. Many balls are done each way.
The 4000 full sequence ball usually goes longer with a smoother backend/beakpoint and handles and requires less oil than the 500/4000 grit ball.
The 500/4000 grit ball hooks earlier, breaks sharper and handles and requires more oil to perform.
On oil that the full sequence 4000 grit performs properly (if these sandings were put on 2 versions of the same model ball, drilled the same and thrown by the same person) then the 500/4000 grit ball would probably lose too much energy in the midlane and either hit the pocket weakly or not hook enough. This difference is more easily see on sport conditions than house oil patterns.
"None are so blind as those who will not see."
