... I am still startled that a cue ball will become smaller but I’m presuming that it takes a long time to happen....
If you look at old red circle cue balls, some of them have become pink circle, or even pink crescent. I just ran into one of these in a pool hall that may have bought the balls in the 1980s.
At the room where I played all the time (Shoreline, Mountain View), they polished the balls every night. About 10 years after they opened, a friend proudly brought in his shiny, new measles cue ball. It was about 2mm larger than the object balls. In turn, the house cue ball was about 2mm smaller than the object balls. Wear is real. Maybe not by polishing, but remember that the pool cloth becomes emery cloth with the addition of the ground sand that is in the chalk.
My first experience with a worn-down cue ball was in 1967 on the tables in the day room when I was in the Air Force. I didn't realize it at first, but my game changed to use almost exclusively draw shots because the cue ball was worn down to the size of a snooker ball (more or less). I got a shot of reality when I went into town to try the local hustlers. The cue ball was strange. It was dull, as if someone had sanded it, and it seemed large. I couldn't draw that ball which meant I couldn't run three balls. It turned out to be a fairly cheap lesson.
