That may be true, but why does it change from from practice or the middle of the first game ? What I’m wondering is how long does it take for that new sanding to start changing.

Some studies have shown that 1000-1500 grit becomes 4000-4500 in 3-6 games.
4000 grit balls also tend towards 4500-5000 grit after the 3 games.

The more worn the lane surface, the faster the ball becomes rougher.  Even synthetics are not as smooth as you might imagine. DOn't the ball is not only going down the lane fairly rapidly, it is also revolving depending on your rev rate. That's a lot of friction.

Remember how much the ball speed changes when the ball hits the breakpoint and starts it hooking!! That's a lot of friction and it's hitting the ball surface.

Based on this, it's not too much to hit the ball with the a damp abrasive pad of the grit you have the ball, by hand after every 3 game set. It takes maybe 30 seconds; then wipe the ball off with a damp paper towel to remove the dust/slurry.

I have seen this with a few different balls. Most recently a Storm Alpha Crux and a GB3. Both need oil, you cant stay in the same place for long with an Alpha crux at 3000 or lower. GB3 is the same way. I have learned this over the last few months, not from stupidity, but by experimentation. I like to see how much versatility I have in my equipment. Once you blow up the lanes, also depending on who you bowl with/against, you will need to move in and catch the oil or ball down and stay close to where you were.