Thank You Jeff, I have been telling several bowlers not to use scotch brite pads on bowling balls because all they do is put scratches on them. There are several cases for both arguments about using S/B pads but I some of my colleagues agree that they aren't the best thing to use.
As far as the original topic goes, along with what's already been suggested, take into consideration the environmental factors taking place at your center. I've watched our league shot go through three different phases during the season while being fully aware that the same pattern is being put down.
At the beginning of the season, here in Orlando, fall is still summer time it seems, surface was on every rack from Dimensions to Black Widow Bites etc. Come december, when we finally get "fall" temps in the 60's and 70's we started to see people put the low grit balls away because they started burning up too soon, or in some cases as the bowlers like to say, "mah ball stopped hookin"..Last week we had a Florida freeze (40's) and I was playing the lanes with a tropical storm and we had a 300 shot with Power Groove Urethane...
Point is, sometimes the weather (depending on your center set up) can have an effect on the oil on your lanes which will effect your ball reaction. Clean your stuff on a normal basis and keep an open mind that sometimes is not just the ball..