It's exact science.  http://en.wikipedia.org/wiki/Radius_of_gyration 

Then differential is the difference between the rg of the core's vertical height and the rg of it's horizontal width.  Basic stuff of course . . lol. 

Compare it to the taboo and its not.

Alright.

I find these numbers interesting. I found this Motiv Ball and its numbers seem almost off the chart to what I normally see with other balls.

Example: Motiv Raptor Talon

16lbs.   Rg - 2.46  Diff. - 0.060
15lbs.   Rg - 2.46  Diff. - 0.060
14lbs.   Rg - 2.48  Diff. - 0.060

The Cruel had the same numbers.

Hey now, that's too much common sense and logic for this forum . .

I wouldn't obsess about pre-drilled rg's and diffs... it's not like anyone throws undrilled balls

Yes. Manufacturers intent is a huge factor. It is why they use a specific core with a specific coverstock. You cannot seperate them.

The Taboo plastic ball has a very aggressive core. It's still a plastic ball. The manufacture uses the core needed with the coverstock to get the correct desired reaction and shape they wish to market.

I am not looking for a ball to cover a ton of boards. In fact this ball is not for me. I am looking for a ball that fits my daughter's profile. She has average speed (16 mph) and below average revs. I have seen a difference already with a used 14 lb. C3 Wrath that she has now, but that ball is dying, needs some oil extraction, complete resurface, or something (I posted this in another thread).

The ball layout was drilled for it to go early. When the Wrath had a good surface on it, it would turn for her. So I am thinking maybe go with a ball that has that design in mind.

It's not the differential that caught my eye on this ball, it was the low Rg. I questioned the numbers because the Differential seemed to be on the high side and was the same across all three ball weights.

Am I off base here?

I see plenty of league bowlers (good speed low revs) using balls like Talon and they have success. They throw around 2nd arrow and have success. The ball doesn't make a big turn but it does recover if gets a little wide on a THS.
 

I wouldn't say you're off base, I'd just say you're giving too much weight or too much importance to the pre drilled rg and diff numbers.  Honestly I really don't pay much attention to the numbers anymore.  I watch videos, watch other people throwing stuff, give a half hearted glance at the rg, and then just get the ball and throw it.  I base my decisions more on design.  I have a Sigma Tour, I wanted something weaker with more length and a stronger backend, so I went Tribal, didn't look at the numbers.  Now I want something with more hook than the Tour and a hard arc, ordered a Covert Revolt, no idea what those numbers are, I just know how it rolls.  Then you just drill the ball and go throw it, and make your small adjustments off what it's giving you. 

I am not looking for a ball to cover a ton of boards. In fact this ball is not for me. I am looking for a ball that fits my daughter's profile. She has average speed (16 mph) and below average revs. I have seen a difference already with a used 14 lb. C3 Wrath that she has now, but that ball is dying, needs some oil extraction, complete resurface, or something (I posted this in another thread).

The ball layout was drilled for it to go early. When the Wrath had a good surface on it, it would turn for her. So I am thinking maybe go with a ball that has that design in mind.

It's not the differential that caught my eye on this ball, it was the low Rg. I questioned the numbers because the Differential seemed to be on the high side and was the same across all three ball weights.

Am I off base here?

I see plenty of league bowlers (good speed low revs) using balls like Talon and they have success. They throw around 2nd arrow and have success. The ball doesn't make a big turn but it does recover if gets a little wide on a THS.