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Author Topic: BTM Rating vs BB.com rating  (Read 705 times)

AlonzoHarris

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BTM Rating vs BB.com rating
« on: January 11, 2017, 10:51:48 AM »
I made a spreadsheet that details the ball ratings and some details. What I've noticed is inconsistencies between bowlingthismonth.com Total Hook number and bowlingball.com Perfect Scale number.

Example: Truth (BTM Total Hook) - 53 (bb.com) - 227.9
               Swerve GT (BTM Total Hook) - 57 (bb.com) - 226.8

So as you can see the Perfect Scale numbers are close to each other but then the BTM total hook numbers aren't even close considering the range they use.

Thoughts on this? Take it with a grain of salt and move on? I liked having stuff I can put on a spreadsheet and compare when trying to decide between a few balls or filling gaps.
Current Bag [Inception Pearl, Marvel Pearl, Rocket Ship, Hammer Black Urethane]

 

Snakster

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Re: BTM Rating vs BB.com rating
« Reply #1 on: January 11, 2017, 12:29:44 PM »
Yeah, total hook ratings have always been a mystery to me; for both of those sources.  BTM at least acknowledges it is probably the least relevant part of their ratings.  As such I pay much more attention to length/torque/backend as well as tweener ratings on the different conditions. 

To this day I have no way of interpreting Perfect Scale.  There is zero explanation of how it is derived or what the number actually represents; other than the supposed relativity to other balls' Perfect Scale rating.  It may be the single most useless 'rating' I have come across to date.  My opinion.
Current bag:
Hammer True Blood
Motiv Octane Carbon
Motiv Forza
Motiv Jackal Ghost

AlonzoHarris

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Re: BTM Rating vs BB.com rating
« Reply #2 on: January 11, 2017, 12:38:11 PM »
Yeah, total hook ratings have always been a mystery to me; for both of those sources.  BTM at least acknowledges it is probably the least relevant part of their ratings.  As such I pay much more attention to length/torque/backend as well as tweener ratings on the different conditions. 

To this day I have no way of interpreting Perfect Scale.  There is zero explanation of how it is derived or what the number actually represents; other than the supposed relativity to other balls' Perfect Scale rating.  It may be the single most useless 'rating' I have come across to date.  My opinion.

So I just sorted the data by Length smallest to largest then backend smallest to largest and it actually makes much more sense for what my eyes have perceived on the lanes. In the past I would sort by either the BTM total hook or Perfect Scale and just seemed ehh.
Current Bag [Inception Pearl, Marvel Pearl, Rocket Ship, Hammer Black Urethane]

charlest

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Re: BTM Rating vs BB.com rating
« Reply #3 on: January 11, 2017, 01:12:22 PM »
I've been comparing BTM vs. BJI numbers for years.
My basic conclusion is that numbers are good ONLY within any one system, if that. Comparing BTM to BB.com or BJI to BTM is fruitless and fraught with peril. You're much better off trying to extract information based on the words used to describe the ball than the numbers generated by any one source.

Look at the reasons behind the numbers:
- what kind of bowler is doing the testing for what purpose?
- how is the ball drilled? For generic use, for maximum hook, for maximum backend, for minimum hook?
- what surface did they test in what oil patterns, to what end?

Many times, the testers don't even know what the ball is designed to do.

BTM puts the best (not necessarily the strongest) drilling for each of their testers: stroker, tweener, cranker. What BB.com does I don't know.

BJI puts a generic drilling on theirs.
"None are so blind as those who will not see."

Aloarjr810

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Re: BTM Rating vs BB.com rating
« Reply #4 on: January 11, 2017, 03:07:04 PM »
The trouble with the Perfect Scale is this:

"The Perfect Scale® uses mathematical formulas along with the manufacturer's current scale to arrive at a uniform and comparable number


Since they use the manufactures hook and length rating numbers in their calculations.

It throws off the calculations because the manufactures don't all use the same criteria to generate their hook & length scale numbers.
Aloarjr810
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