I'm sure the pin setting machines have little or nothing to do with it as opposed to other variables. More likely the lane surface, oil condition, channel depth, pin curtains, etc.
I have bowled in houses where pins bouncing out from the curtains was routine, and others where it rarely happens. There is also a minimum and maximum channel depth to remain legal. Of course where the channels are more shallow, the 6 pin taps the 10 pin (opposite for leftys) more frequently instead of staying in the channel.
There are various types of pins, too. I'm no expert in this area, so maybe there's an experienced mechanic who can answer, too.
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Lane Carter, Strike Zone Pro Shops - Salt Lake City, Utah
Brunswick Amateur Staff