I leave these every week or so, i bowl on mendez pin which have magnets on top of each pin. Plus they screw with the oil's they use every couple of months, usually the kegel oil that is heaviest. I had a 230 pro shop friend a few weeks ago sub for me and he told me after struggling with a 628 that this house is death too shoot. I laughed because balls never roll the same here as any where else in town, the new pyro from storm is virtually a spare ball in another friends hand to is 500 rpm's plus. He told me the ball was pretty straight which in his hands is almost not believable except when you bowl at this hole. Maybe you were on mendez magnetic pins and did not realize it lol