FYI...
source:http://www.bowlingfans.com/jeff/ballreactionbasics.html
One note about the mass bias - On asymmetric core bowling balls, the mass bias is marked on the ball. Each company does this in different ways. Storm uses an "MC2" while Ebonite uses a little picture of a bomb. They are not difficult to find when they are marked. However, balls with symmetric cores do not have a marked mass bias. These balls still have a mass bias, but it will not be as strong with respect to reaction effect.
To find the mass bias in non-marked balls, draw a line starting at the pin in the direction of the CG. Draw the line through the CG. Once you get to 6 3/4" from the pin, stop. This is the mass bias point. It is helpful to weigh the ball on a dodo scale before you do this because the CG is often marked inaccurately on bowling balls.
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"You've got to be very careful
if you don't know where you're going,
because you might not get there."
--Yogi Berra
Edited on 3/20/2006 1:39 PM