Is there any approximation/chart so we can know in general by how much, these values change, after drilling ? And if they are very different depending on layout, how do they change in relation to some popular layouts.

Not fully what your asking for, But I think goes with it and just to get this started, MO posted this one time:


Suggestion for using the undrilled ball #s to help anticipate ball reaction.

1) Take the min. RG # and add 70% of the total diff to it. That'll give you the approximate RG of the PAP for about 80% of the layouts. The RG of the PAP is the only RG that matters to the motion of the drilled ball.

2) Divide the int. diff. of the undrilled ball by the total diff. of the undrilled ball. That'll give you the diff. ratio. That tells you the potential of the ball to respond to friction.

Diff. ratios (using the drilled diff.):
>.45 is strong reaction
.25 to .45 is medium reaction
<.25 is smooth reaction

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"REMEMBER, it isn't how much the ball hooks, it's where."

Thank you. The manufacturers though mention the min RG on which location?

In any case let's take a ball as an example and do the math, to see if i got it right :

Mako Attack. At 15lbs. it has
RG: 2.48 (i think they post the min RG when not specified, right? ),
Diff: 0.053
Intermediate Diff: 0.014

So 2.48 + 70/100 x 0.053 = 2.51 So after drilling, for 80% of layouts, the RG of the PAP will be 2.51

Then 0.014/0.053 = 0.264 Does this mean that the "intermediate diff" or "mass bias" that manufacturers mention, gives no real info by itself? (like higher = stronger reaction) ? Because even if it is high, if the total Diff is also very high, the ratio will still be not so high.

Minimum RG is at the pin. RG of the PAP affects ball motion.

_________________
Benchmark Bowling Pro Shop
Byron

RH
PAP: 5.625" x 0
REVRATE: 360
SPEED: 17mph at release
AR: 55º
AT: 7º

In a core related video (see below), i saw that, in general, when you drill a ball, the RG rises, and the Diff lowers, and the Intermediate Diff also rises.

Would you say that this is a general rule for most balls/layouts?