Table Difficulty Factor (TDF) for measuring table "toughness"

JC

Coos Cues
Sounds easy!:p

So, what was the original nose height above the bed and what is it now? I'd like to know to see how mine compares to the current Diamond spec.

The nose height didn't change from about 1 7/16. The rubber was just rotated slightly at the nose toward the sky to bring it back to that height after shaving a sixteenth off the thickness of the rail. This slight rotation of the rubber makes the ball compress it differently and is supposed to solve the banking short. Diamond tables still bank short IMO, especially with a firm hit. We just adjust our aim to accommodate it and call it fixed.

JC
 

Sloppy Pockets

AzB Silver Member
Silver Member
Diamond tables still bank short IMO, especially with a firm hit. We just adjust our aim to accommodate it and call it fixed.

My rails bank horribly short, so maybe that's another reason to get them worked on. I've gotten to using outside on every bank shot or I won't even be able to get close to the pocket. I think the combination of deflection and spin gets me where I should be. Of course, I live 1000 miles from Kentucky, so banks have never been a real strength of mine. :eek:
 

cigardave

Who's got a light?
Silver Member
Sounds easy!:p

So, what was the original nose height above the bed and what is it now? I'd like to know to see how mine compares to the current Diamond spec.
1 7/16" is the correct nose height.

It's that before the re-cal and the same afterwards.

Taking 1/16" off the thickness of the subrails is counteracted by the 3 degree change in the bevel of the subrail's face to which the cushion is glued.
 
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Sloppy Pockets

AzB Silver Member
Silver Member
Anyone having trouble getting an accurate shelf depth I think the way Iusedtoberich measured it in his BU video is very accurate.

Yes, very good. You have to use a square of some sort to get a true measurement of the shelf depth. The 1 7/8" distance between the cushion nose and the table bed would surely introduce a ton of parallax error if you just tried to eyeball it.

The more I think of it, the likelihood of everybody being able to measure accurately is a big downside to this database that can't be ignored. I've been a precision woodworker my whole life, so extremely accurate measuring is second nature to me now. Most folks probably think they can do a fine job of measuring their table dimensions, but tight tolerances are actually rather difficult to maintain. Little errors are cumulative, and the results can become quite skewed.

Back when I worked in the lab we had to measure tumor volume in mice. We used a cheap plastic dial caliper to measure the tumors in three axes. I was shown how to do it, but then an older and much more experienced worker did the actual measurements for our records.

I felt a bit insulted given my previous experience in measuring things. When I compared both his volumes and mine I found out that there was up to a 20% difference in the volumes we derived because the small difference in each measurement was multiplied through. They used his because he was consistent over the years, and consistency (precision) often trumps accuracy in studies such as these.
 

cigardave

Who's got a light?
Silver Member
Yes, very good. You have to use a square of some sort to get a true measurement of the shelf depth. The 1 7/8" distance between the cushion nose and the table bed would surely introduce a ton of parallax error if you just tried to eyeball it.

The more I think of it, the likelihood of everybody being able to measure accurately is a big downside to this database that can't be ignored. I've been a precision woodworker my whole life, so extremely accurate measuring is second nature to me now. Most folks probably think they can do a fine job of measuring their table dimensions, but tight tolerances are actually rather difficult to maintain. Little errors are cumulative, and the results can become quite skewed.

Back when I worked in the lab we had to measure tumor volume in mice. We used a cheap plastic dial caliper to measure the tumors in three axes. I was shown how to do it, but then an older and much more experienced worker did the actual measurements for our records.

I felt a bit insulted given my previous experience in measuring things. When I compared both his volumes and mine I found out that there was up to a 20% difference in the volumes we derived because the small difference in each measurement was multiplied through. They used his because he was consistent over the years, and consistency (precision) often trumps accuracy in studies such as these.
Given that confession, I propose that hereafter you shall be referred to as Sloppy Measurements. :thumbup:
 

iusedtoberich

AzB Silver Member
Silver Member
I read up to Friday night, then had to leave town. Some comments up through that point:

1. I like the idea of what you are trying to do. Its seems like a great idea, and a way to put numbers to tables. Some of the below might be the minutia, but some might be reasonable to include.

2. I'm glad your 1.0 number is a 9' table, and not an "average". If it was truly an "average" it would probably be closer to the specs of a 7' bar table, as there are probably a lot more bar tables in the country than 9' tables, if you want by quantities. And if you want by average of available table sizes, well, then it would fall probably around an 8' table specs, as bar tables start at 6', and the biggest tables available for pool (not snooker or carom) are 10' tables.

3. If we remove the word "average" what shall we replace it with for the 1.0 value in each criterion? Also, what should that 1.0 value be based on? How about we make the 1.0 value based on the Diamond Pro/Am table, and actually call the 1.0 value "Professional Tournament Table Difficulty Factor". The reasons for this are:
a. Almost every professional tournament in the US for the last 10 years has been played on this table. So most of us are familiar with this spec.
b. Unlike GC tables, almost every Diamond set up in a pool room or home use is set up the exact same way as a tournament spec table. This is due to the way the table is designed and built from the factory.
c. Having the 1.0 value be "tournament condition" is imo a nice thing. Even though it will put almost everyones "home" table to be easier, so what. Its what the pros play on for every tournament, and should be the "standard".


5. I think your documents should be rev controlled, or date controlled, so we know what version we are looking at. I think you had that on your other documents, but not this one (as of Friday night)

6. The angle cannot be calculated reliably with just the pocket front to back different. You need one more leg of the triangle to calculate the angle. Maybe if the rubber cushion width is the same across all tables, this would not be necessary. Is it? I don't know... Do you? Maybe the player can add that measurement in the formula, and you'd have the other leg of the triangle.

7. The drawing I think should be revised or clarified. Where do you measure when the points of the pocket are a bit rounded, like they are on most tables? Where do you measure the throat width of the pocket (for example, there is a bit of a flat spot on the throat width of smaller width pockets, that extents inside of the plastic pocket bucket). Real world pockets don't necessarily look like your picture (even pockets set up by top mechanics)

8. Measuring the throat depth should include the use of a square held against a ruler spanning the points of the pocket. Lots of household goods can qualify as a square: A music CD case, a cell phone, a deck of cards, a factory corner of a piece of cardboard, etc.
 

cigardave

Who's got a light?
Silver Member
I read up to Friday night, then had to leave town. Some comments up through that point:

1. I like the idea of what you are trying to do. Its seems like a great idea, and a way to put numbers to tables. Some of the below might be the minutia, but some might be reasonable to include.

2. I'm glad your 1.0 number is a 9' table, and not an "average". If it was truly an "average" it would probably be closer to the specs of a 7' bar table, as there are probably a lot more bar tables in the country than 9' tables, if you want by quantities. And if you want by average of available table sizes, well, then it would fall probably around an 8' table specs, as bar tables start at 6', and the biggest tables available for pool (not snooker or carom) are 10' tables.

3. If we remove the word "average" what shall we replace it with for the 1.0 value in each criterion? Also, what should that 1.0 value be based on? How about we make the 1.0 value based on the Diamond Pro/Am table, and actually call the 1.0 value "Professional Tournament Table Difficulty Factor". The reasons for this are:
a. Almost every professional tournament in the US for the last 10 years has been played on this table. So most of us are familiar with this spec.
b. Unlike GC tables, almost every Diamond set up in a pool room or home use is set up the exact same way as a tournament spec table. This is due to the way the table is designed and built from the factory.
c. Having the 1.0 value be "tournament condition" is imo a nice thing. Even though it will put almost everyones "home" table to be easier, so what. Its what the pros play on for every tournament, and should be the "standard".


5. I think your documents should be rev controlled, or date controlled, so we know what version we are looking at. I think you had that on your other documents, but not this one (as of Friday night)

6. The angle cannot be calculated reliably with just the pocket front to back different. You need one more leg of the triangle to calculate the angle. Maybe if the rubber cushion width is the same across all tables, this would not be necessary. Is it? I don't know... Do you? Maybe the player can add that measurement in the formula, and you'd have the other leg of the triangle.

7. The drawing I think should be revised or clarified. Where do you measure when the points of the pocket are a bit rounded, like they are on most tables? Where do you measure the throat width of the pocket (for example, there is a bit of a flat spot on the throat width of smaller width pockets, that extents inside of the plastic pocket bucket). Real world pockets don't necessarily look like your picture (even pockets set up by top mechanics)

8. Measuring the throat depth should include the use of a square held against a ruler spanning the points of the pocket. Lots of household goods can qualify as a square: A music CD case, a cell phone, a deck of cards, a factory corner of a piece of cardboard, etc.
With your knowledge of the issues at hand, I'd say that you are rich... no past tense required.
 

dr_dave

Instructional Author
Gold Member
Silver Member
In regards to the Bonus Ball table. While I have no access to the table for measurements, I recall a thread ( here http://forums.azbilliards.com/showthread.php?t=322591&highlight=bonus+ball+pockets ) that may allow you to at least get in the neighborhood until hard numbers surface.
After looking through the Bonus Ball thread with the pocket photo, this is the best I can figure:

mouth: 3 7/8", throat: 3 3/4", (mouth-throat): 1/8", shelf: 3/4"

giving:

Bonus Ball -- 9':1.00 -- 3 7/8":1.20 -- 1/8":1.00 -- 3/4":1.00 -- 1.20 (Bonus Ball table)

I've also added finer divisions on the tough end of the pocket size scale:
table_difficulty_PSF.jpg

Here's the latest updated list:

Data reported by AZB users in table difficulty factor (TDF) order, based on the table size factor (TSF), pocket size factor (PSF), pocket angle factor (PAF), and pocket shelf factor (PLF):

name -- TSF -- PSF -- PAF -- PLF -- TDF
tough 10' -- 10':1.10 -- 4":1.15 -- 3/4":1.02 -- 1 7/8":1.03 -- 1.33
example "B" -- 9':1.00 -- 3 7/8":1.20 -- 5/8":1.00 -- 1 7/8":1.03 -- 1.24
Bonus Ball -- 9':1.00 -- 3 7/8":1.20 -- 1/8":1.00 -- 3/4":1.00 -- 1.20 (Bonus Ball table)
rexus31 -- 9':1.00 -- 4":1.15 -- 3/8":1.00 -- 1":1.00 -- 1.15
FatBoy -- 9':1.00 -- 4":1.15 -- 1/4":1.00 -- 1":1.00 -- 1.15
TATE -- 9':1.00 -- 4":1.15 -- 1/4":1.00 -- 7/8":1.00 -- 1.15
Qaddiction -- 9':1.00 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":1.00 -- 1.10
rexus31 friend GC -- 9':1.00 -- 4 1/4":1.10 -- 1/4":1.00 -- 15/16":1.00 -- 1.10
cigardave -- 9':1.00 -- 4 1/2":1.05 -- 3/4":1.02 -- 1 3/4":1.00 -- 1.07 (typical Pro-Cut Diamond)
SloMoHolic -- 9':1.00 -- 4 3/8":1.05 -- 5/8":1.00 -- 1 3/8":0.98 -- 1.03
JC -- 9':1.00 -- 4 7/16":1.05 -- 9/16":1.00 -- 1 3/8":0.98 -- 1.03
"standard" table -- 9':1.00 -- 4 9/16":1.00 -- 9/16":1.00 -- 1 5/8":1.00 -- 1.00 ("standard")
Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10 -- 1 3/4":1.00 -- 0.99
Dopc -- 8':0.90 -- 4.5":1.05 -- 3/4":1.02 -- 1 1/4":1.00 -- 0.96
12squared -- 9':1.00 -- 4 7/8":0.95 -- 3/4":1.02 -- 1 1/2":0.98 -- 0.95 (typical Gold Crown)
MSchaffer -- 9":1.00 -- 5 1/10":0.90 -- <3/4":1.02 -- >1 3/4":1.03 -- 0.95
Neil -- 7':0.85 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":1.00 -- 0.94
BRussell -- 8':0.90 -- 5":0.95 -- 13/16":1.05 -- 1 1/2":0.98 -- 0.88
dr_dave -- 8':0.90 -- 4 3/4":0.95 -- 5/8":1.00 -- 1 3/8":0.98 -- 0.84
example "A" -- 8':0.90 -- 5":0.95 -- 1/2":0.98 -- 1 3/8":0.98 -- 0.82
Valley "bar box" -- 7':0.85 -- 4 1/2":1.05 -- 0":0.94 -- 3/4":0.95 -- 0.80 (typical Valley/Dynamo "bar box")
 
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dr_dave

Instructional Author
Gold Member
Silver Member
Knowing the width of the cushions (usually 2" I'm told), you can measure along the long sides to the points I've drawn at the back of the throat and use a little trig to get the actual facing angles. That's all that matters when you are considering the acceptance/rejection of balls hit into it.

Not trying to nitpick, but these small errors in measurement are another fly in the ointment in building a database with info garnered from various sources.
Excellent illustration and point. This is how I am assuming people are measuring the mouth and throat dimensions (at the projected-line intersections of the cushion noses, pocket facings, and rail edges).

Thanks again,
Dave
 

dr_dave

Instructional Author
Gold Member
Silver Member
What makes that pocket play hard is the facing angles, not the actual measurements. They had to be cut that way because your pocket liners are way too wide to have the cushion terminate in a point at the throat.

I put in some lines on the Diamond spec pocket to show what the real angle is. It's even worse than your numbers would indicate.

Knowing the width of the cushions (usually 2" I'm told), you can measure along the long sides to the points I've drawn at the back of the throat and use a little trig to get the actual facing angles. That's all that matters when you are considering the acceptance/rejection of balls hit into it.

Not trying to nitpick, but these small errors in measurement are another fly in the ointment in building a database with info garnered from various sources.
FYI, I've added the following to the table difficulty factor (TDF) resource page, for easy future reference:

from Sloppy Pockets in AZB post, concerning how to properly measure the pocket mouth and throat dimensions (at the intersections of the yellow lines, not at the labeled red dimensions):

pocket_measurements.jpg

Thanks again,
Dave
 
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Sloppy Pockets

AzB Silver Member
Silver Member
Given that confession, I propose that hereafter you shall be referred to as Sloppy Measurements. :thumbup:

LOL! No, no, nothing sloppy about my measurements.

I guess I failed to make my point properly. The older scientist had been doing it his way for a long time and was consistent enough that his data was acceptable for the studies we were doing, which examined tumor growth rates. There is no doubt in my mind that my actual measurements were a lot more accurate than the ones he took (I saw first-hand how "sloppy" he was with the caliper), but they had been using his measurements for many years, so there was a consistency across all of his data sets that allowed the rates to be directly compared. This consistency allowed data from five years before to be compared with data gotten last week. Introducing my more accurate measurements would have done nothing but introduce a confound to our work.

I see the same thing occurring when I see the eye doctor. Even using an extremely accurate ophthalmological device to measure my eye pressure, the doctor and each tech will get slightly different results. Neither one is more "correct", but since I have a 1 in 100,000 type of eye injury that he has been treating for over five years, he goes with his own readings because he is consistent in his own technique.

Measuring things accurately is an art form. Even with a Starrett micrometer folks will get slight variations in measurements. A "micrometer feel" obtained over long practice allows each of your measurements to have consistency with all the others you take. Contrast that with a bunch of pools players who may or may not be good at this at all, or may not triple-check their measurements like I do, or use two or more ways to take the measurements and average the results, etc.

I'm just about certain that this will lead to a lot of inconsistency in the data, and this should not be ignored if the study is to have any credibility for future reference. Without Dr. Dave coming to each of our homes to personally take each measurement, the best he can do is to strongly suggest particular ways to take the measurements that will lead to the most consistent results. The whole argument that this info can be used to normalize the BU test results across a wide range of tables is a bit specious IMHO, but I applaud the efforts anyway. I'm interested to see how this develops no matter what the outcome is, but let's at least start with a set of techniques that allow measurements to be taken in a predictable and repeatable way.
 

dr_dave

Instructional Author
Gold Member
Silver Member
I read up to Friday night, then had to leave town. Some comments up through that point:

1. I like the idea of what you are trying to do. Its seems like a great idea, and a way to put numbers to tables. Some of the below might be the minutia, but some might be reasonable to include.

2. I'm glad your 1.0 number is a 9' table, and not an "average". If it was truly an "average" it would probably be closer to the specs of a 7' bar table, as there are probably a lot more bar tables in the country than 9' tables, if you want by quantities. And if you want by average of available table sizes, well, then it would fall probably around an 8' table specs, as bar tables start at 6', and the biggest tables available for pool (not snooker or carom) are 10' tables.

3. If we remove the word "average" what shall we replace it with for the 1.0 value in each criterion? Also, what should that 1.0 value be based on? How about we make the 1.0 value based on the Diamond Pro/Am table, and actually call the 1.0 value "Professional Tournament Table Difficulty Factor". The reasons for this are:
a. Almost every professional tournament in the US for the last 10 years has been played on this table. So most of us are familiar with this spec.
b. Unlike GC tables, almost every Diamond set up in a pool room or home use is set up the exact same way as a tournament spec table. This is due to the way the table is designed and built from the factory.
c. Having the 1.0 value be "tournament condition" is imo a nice thing. Even though it will put almost everyones "home" table to be easier, so what. Its what the pros play on for every tournament, and should be the "standard".
Thanks for the input.

5. I think your documents should be rev controlled, or date controlled, so we know what version we are looking at. I think you had that on your other documents, but not this one (as of Friday night)
Sorry, but I haven't saved or dated any of my previous versions. I don't think the current version will change very much; but if it does, I will start added dates. Good idea.

6. The angle cannot be calculated reliably with just the pocket front to back different. You need one more leg of the triangle to calculate the angle. Maybe if the rubber cushion width is the same across all tables, this would not be necessary. Is it? I don't know... Do you? Maybe the player can add that measurement in the formula, and you'd have the other leg of the triangle.
I am assuming the cushion width is very close to 2". I think this is a good assumption.

7. The drawing I think should be revised or clarified. Where do you measure when the points of the pocket are a bit rounded, like they are on most tables? Where do you measure the throat width of the pocket (for example, there is a bit of a flat spot on the throat width of smaller width pockets, that extents inside of the plastic pocket bucket). Real world pockets don't necessarily look like your picture (even pockets set up by top mechanics)
Excellent point. My idealized drawing shows how the measurements should be taken (at the intersections of the ideal lines through the cushion noses, pocket facings and rail lines), but I agree that many people would be confused by how to take the measurements on an actual table that doesn't look like the drawing. I've added Sloppy Pocket's image to the table difficulty factor (TDF) resource page to help. I'll also try to revise the drawing in the document to show this more clearly.

8. Measuring the throat depth should include the use of a square held against a ruler spanning the points of the pocket. Lots of household goods can qualify as a square: A music CD case, a cell phone, a deck of cards, a factory corner of a piece of cardboard, etc.
Good idea. I honestly don't expect people to be this careful; although, it would be nice if they were.

Thank you for the feedback and input,
Dave
 

dr_dave

Instructional Author
Gold Member
Silver Member
My TDF = 0.95 ?

Mouth = 4 9/16"
Throat = 3 15/16
Shelf = 1 3/16"
That's correct, assuming your table is 9'.

I've added the following to the list:

mamics -- 9':1.00 -- 4 9/16":1.00 -- 5/8":1.00 -- 1 3/16":0.95 -- 0.95

Thanks,
Dave
 

dr_dave

Instructional Author
Gold Member
Silver Member
The whole argument that this info can be used to normalize the BU test results across a wide range of tables is a bit specious IMHO, but I applaud the efforts anyway.
I agree with you about the "specious" part (after I looked up the definition to be sure). I don't see using the TDF factor to adjust BU scores in any official way. To me, the purpose is to allow people to put their scores into "perspective" or do a rough comparison of scores on different tables. That's how I've worded it on the BU Rating System page.

I'm interested to see how this develops no matter what the outcome is
Me too.

but let's at least start with a set of techniques that allow measurements to be taken in a predictable and repeatable way.
Sounds good to me. Your illustration has certainly helped.

Thank you for your input and good ideas,
Dave
 

Sloppy Pockets

AzB Silver Member
Silver Member
After looking through the Bonus Ball thread with the pocket photo, this is the best I can figure:

mouth: 3 7/8", throat: 3 3/4", (mouth-throat): 1/8", shelf: 3/4"

giving:

Bonus Ball -- 9':1.00 -- 3 7/8":1.20 -- 1/8":1.00 -- 3/4":1.00 -- 1.20 (Bonus Ball table)

I've also added finer divisions on the tough end of the pocket size scale:
table_difficulty_PSF.jpg

So the players aren't lying, the BB table really IS harder. :thumbup:

I like the finer divisions. I was going to suggest this as things progressed, but I'm glad don't need my help figuring things out.:thumbup2:

Why not add them across the entire range, though? If you listen to the pros, there is a definite difference between the way 4 1/8" pockets play compared to 4 1/4" pockets. Since most tables today have pockets between 4" and 4 1/2" across the throat, this range would seem to me to be the one that needs the finest gradations.
 

67tbird

AzB Silver Member
Silver Member
My table
8'
4 1/4" mouth
4" throat
1 1/2" shelf
.91 TDF

- Andy

Sent from my C771 using Tapatalk 2
 

Mr. Bond

Orbis Non Sufficit
Gold Member
Silver Member
Random thoughts:

Perhaps it would be good to measure all the pockets on a given table, (since there may be variances from pocket to pocket) then add them up and use the averages...

Perhaps a degree of "difficulty" should be added if the cushion facing vertical angle is less than say 14 degrees...(15 or more being easier?)
 

JC

Coos Cues
After looking through the Bonus Ball thread with the pocket photo, this is the best I can figure:

mouth: 3 7/8", throat: 3 3/4", (mouth-throat): 1/8", shelf: 3/4"

giving:

Bonus Ball -- 9':1.00 -- 3 7/8":1.20 -- 1/8":1.00 -- 3/4":1.00 -- 1.20 (Bonus Ball table)

I've also added finer divisions on the tough end of the pocket size scale:
table_difficulty_PSF.jpg

Here's the latest updated list:

Data reported by AZB users in table difficulty factor (TDF) order, based on the table size factor (TSF), pocket size factor (PSF), pocket angle factor (PAF), and pocket shelf factor (PLF):

name -- TSF -- PSF -- PAF -- PLF -- TDF
tough 10' -- 10':1.10 -- 4":1.15 -- 3/4":1.02 -- 1 7/8":1.03 -- 1.33
example "B" -- 9':1.00 -- 3 7/8":1.20 -- 5/8":1.00 -- 1 7/8":1.03 -- 1.24
Bonus Ball -- 9':1.00 -- 3 7/8":1.20 -- 1/8":1.00 -- 3/4":1.00 -- 1.20 (Bonus Ball table)
rexus31 -- 9':1.00 -- 4":1.15 -- 3/8":1.00 -- 1":1.00 -- 1.15
FatBoy -- 9':1.00 -- 4":1.15 -- 1/4":1.00 -- 1":1.00 -- 1.15
TATE -- 9':1.00 -- 4":1.15 -- 1/4":1.00 -- 7/8":1.00 -- 1.15
Qaddiction -- 9':1.00 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":1.00 -- 1.10
rexus31 friend GC -- 9':1.00 -- 4 1/4":1.10 -- 1/4":1.00 -- 15/16":1.00 -- 1.10
cigardave -- 9':1.00 -- 4 1/2":1.05 -- 3/4":1.02 -- 1 3/4":1.00 -- 1.07 (typical Pro-Cut Diamond)
SloMoHolic -- 9':1.00 -- 4 3/8":1.05 -- 5/8":1.00 -- 1 3/8":0.98 -- 1.03
JC -- 9':1.00 -- 4 7/16":1.05 -- 9/16":1.00 -- 1 3/8":0.98 -- 1.03
"standard" table -- 9':1.00 -- 4 9/16":1.00 -- 9/16":1.00 -- 1 5/8":1.00 -- 1.00 ("standard")
Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10 -- 1 3/4":1.00 -- 0.99
Dopc -- 8':0.90 -- 4.5":1.05 -- 3/4":1.02 -- 1 1/4":1.00 -- 0.96
12squared -- 9':1.00 -- 4 7/8":0.95 -- 3/4":1.02 -- 1 1/2":0.98 -- 0.95 (typical Gold Crown)
MSchaffer -- 9":1.00 -- 5 1/10":0.90 -- <3/4":1.02 -- >1 3/4":1.03 -- 0.95
Neil -- 7':0.85 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":1.00 -- 0.94
BRussell -- 8':0.90 -- 5":0.95 -- 13/16":1.05 -- 1 1/2":0.98 -- 0.88
dr_dave -- 8':0.90 -- 4 3/4":0.95 -- 5/8":1.00 -- 1 3/8":0.98 -- 0.84
example "A" -- 8':0.90 -- 5":0.95 -- 1/2":0.98 -- 1 3/8":0.98 -- 0.82
Valley "bar box" -- 7':0.85 -- 4 1/2":1.05 -- 0":0.94 -- 3/4":0.95 -- 0.80 (typical Valley/Dynamo "bar box")

The thing about the bonus ball table for pros is that once your aiming gets to a certain level of precision and consistency, pocket size is no longer as important as how it accepts balls. Take those 3 and 7/8 pockets and give the facings 144 degrees and add a half inch of shelf and they do not become "a bit harder", they become a pin ball machine.
 
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