Thank you. But I think I need to elaborate a bit.

Been using tape in the front for sizing as the warm weather makes the fit snugger and the cold weather looser.  Also when bowling more frequently or less frequently, and this occurs more in Spring and Fall, but pretty much thruout the year,

The thing about the textured (white) tape at the back of the thumbhole is that it only seems to happen once a year, and unlike the tape at the front, where a change in the the FEEL is very obvious, either dropping the ball or hanging up in it, the effect of the tape at the back of the hole is more subtle.

The last few weeks it didn't feel too loose or too tight, it just seemed that my timing was off and I was lifting or turning my wrist too early or too late.  Finally realized...  after removing the tape at the back... that it was probably cause I wasn't coming out of the ball cleanly.  But the difference was so subtle that it was kind of an act of desperation that I decided to remove the tape at the back.

I guess what I'm kind of asking is whether there is a way I can avoid this painful process next year.  Maybe an earlier sign that the thumb's fit is just slightly off -----before I bowl badly for several weeks.

Yesterday took the tape at the back of the hole out of 3 different balls and of course the scores were better, but the games were sooooo   easy.   Was back to throwing unconciously and not thinking too much while delivering the ball (or in between shots).