Well, I guess this no longer matters. Against my better judgment, I used this ball in league for the first time at a different house that has old, shaky lane equipment. Sure enough, during practice, two balls got stuck in the ball return, and it was several minutes before it was realized they were there and could be gotten out by the lane people. You could smell a burning plastic type smell. My HRR was the one making the smell, and had a couple of deep, wide grooves burned into it with about 6 inches of melted resin hanging from each groove. Totally wrecked it. Even though this place has a "not responsible for ball damage" policy and signs on every lane, they stepped up and said that they will replace my ball with a new one. Bad luck for me that this happened to my best ball (and best fitting thumb hole), but I'm glad they did the right thing. BTW, I'm a 14 year multi-league bowler at this house, and have spent significant money there, and have brought in several new league bowlers over the years, so this may have been a factor in getting my ball replaced.