With the core itself, the difference is if you take a symmetrical core and cut it in half from the pin down, both sides will be exactly the same. However, if you take an asymmetrical core and cut it in half from the pin down, one side will be different than the other. The "extra" core on the one side is the mass bias, as there is more "mass" on that side of the ball than the other.
You can also achieve a mass bias through different densities, but it does not creat an asymmetrical core all of the time.
Clint
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Clint Daley-Owner
Lets Go Bowling Daley
Inside Hunt Club Lanes
Salem, Ohio 44460
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