I always check a plugged ball for cg location, it usually ends up fairly close to the marked cg. I only check a new ball if the numbers appear to be suspect. If I'm drilling for someone that doesn't want a balance hole and using a layout that will be close on static legality I check the weights before drilling to be sure it will be OK. Side weight will be very close to the check, finger/thumb weight will depend on the size and depth of the holes drilled but will give a good estimate. -- JohnP