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

dr_dave

Instructional Author
Gold Member
Silver Member
My 9' GC3 has a 1.0 tsf, 4 7/16 pocket openings for 1.05 psf, 3 7/8 throat for a 9/16th difference paf 1.0 and a 1 3/8 shelf for a .98 plf. .98x1.05=1.029 or an average, honest table.

My 8' Olhausen has 5" mouth, 4 3/16 " throat, 1 1/2" shelf.
BRussell -- 8':.90 -- 5":.95 -- 13/16":1.05 -- 1 1/2":.98 -- .88

Thanks. Here's the 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
example "B" -- 9':1.00 -- 3 7/8":1.20 -- 5/8":1.00 -- 1 7/8":1.03 -- 1.24
rexus31 -- 9':1.00 -- 4":1.20 -- 3/8":1.00 -- 1":1.00 -- 1.20
FatBoy -- 9':1.00 -- 4":1.20 -- 1/4":1.00 -- 1":1.00 -- 1.20
TATE -- 9':1.00 -- 4":1.20 -- 1/4":1.00 -- 7/8":1.00 -- 1.20
Qaddiction -- 9':1.00 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":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
Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10 -- 1 7/8":1.03 -- 1.02
"standard" table -- 9':1.00 -- 4 9/16":1.00 -- 9/16":1.00 -- 1 5/8":1.00 -- 1.00 ("standard")
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)
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")
 

dr_dave

Instructional Author
Gold Member
Silver Member
Notice how the Bonus Ball announcers keep going on and on about how tight the pockets on their Rasson tables are
Does anybody know the details on these pockets, or have access to one to take measurements? If so, please report it so we can see how the BB table ranks.

Thanks,
Dave
 

dr_dave

Instructional Author
Gold Member
Silver Member
Does anybody know the details on these pockets, or have access to one to take measurements? If so, please report it so we can see how the BB table ranks.
I'm also still hoping some people will post data for some really "interesting" tables. For example, how about a 10' table with tight pockets? How about a triple-shimmed 9' table that spits out shots that would easily go on any reasonable table? How about a "bar box" that sucks quarters better than any other? Anybody have access to some of these? If so, please post the info along with your comments.

Thanks,
Dave
 

MSchaffer

AzB Silver Member
Silver Member
9' Gold Crown II:

TSF: 9'= 1.00
PSF= 5.105"= 0.90
PAF= 0.733 = 1.02
PLF= 1.76" = 1.03

TDF=0.945
 

Fatboy

AzB Silver Member
Silver Member
if i take a Valley Barbox and play 10 ball X 10 racks and added up all the balls potted then X 0.82 = XX.XX. Then do the exact thing on my table 10 racks of 10 balls X 1.20 = YY.YY


100 % of the time YY.YY > XX.XX , i'm certain of that.


I can do this test, i have access to a Vally (almost level, bone stock table 15 years old, the rails are tight so it actually plays good. And On my box do the same test 10 minutes later-the tables a 0.5 Miles apart from each other. I'll use either Centennial or Armith balls and measles CB-same balls on both tables to make it as consistent as possible.


that will be some real world numbers, im 65% instroke right now. Good enough I feel comfortable playing, and consistent enough for reliable scoring.


I do need a new tip tho. mine is toast. Mid next week i can do this.
 

dr_dave

Instructional Author
Gold Member
Silver Member
9' Gold Crown II:

TSF: 9'= 1.00
PSF= 5.105"= 0.90
PAF= 0.733 = 1.02
PLF= 1.76" = 1.03

TDF=0.945
I've added you to the list as:
MSchaffer -- 9":1.00 -- 5 1/10":0.90 -- <3/4":1.02 -- >1 3/4":1.03 -- 0.95

Thanks,
Dave
 

dr_dave

Instructional Author
Gold Member
Silver Member
if i take a Valley Barbox and play 10 ball X 10 racks and added up all the balls potted then X 0.82 = XX.XX. Then do the exact thing on my table 10 racks of 10 balls X 1.20 = YY.YY


100 % of the time YY.YY > XX.XX , i'm certain of that.


I can do this test, i have access to a Vally (almost level, bone stock table 15 years old, the rails are tight so it actually plays good. And On my box do the same test 10 minutes later-the tables a 0.5 Miles apart from each other. I'll use either Centennial or Armith balls and measles CB-same balls on both tables to make it as consistent as possible.


that will be some real world numbers, im 65% instroke right now. Good enough I feel comfortable playing, and consistent enough for reliable scoring.


I do need a new tip tho. mine is toast. Mid next week i can do this.
Sounds good. Ideally, you should do the test several times on each table (taking the middle value on each), or at least throw out your low and high rack scores on each set to reduce the luck factor some.

I look forward to seeing the results of your experiment.

Thanks,
Dave
 

Neil

AzB Silver Member
Silver Member
Neil,

FYI, after all of the changes since starting this thread, your table now rates much higher. Here's the current data for your table:

Neil -- 7':0.85 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":1.00 -- 0.94

Maybe this still isn't as high as you think it should be, but this is what the current system is giving. What do you think about the 94% number, applied to an average player?

Here's the entire list to date:

name -- TSF -- PSF -- PAF -- PLF -- TDF
example "B" -- 9':1.00 -- 3 7/8":1.20 -- 5/8":1.00 -- 1 7/8":1.03 -- 1.24
rexus31 -- 9':1.00 -- 4":1.20 -- 3/8":1.00 -- 1":1.00 -- 1.20
FatBoy -- 9':1.00 -- 4":1.20 -- 1/4":1.00 -- 1":1.00 -- 1.20
TATE -- 9':1.00 -- 4":1.20 -- 1/4":1.00 -- 7/8":1.00 -- 1.20
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
Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10 -- 1 7/8":1.03 -- 1.02
"standard" table -- 9':1.00 -- 4 9/16":1.00 -- 9/16":1.00 -- 1 5/8":1.00 -- 1.00 ("standard")
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)
Neil -- 7':0.85 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":1.00 -- 0.94
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")


This is still a "work in progress." Thanks to everybody again for the valuable input.

Regards,
Dave

Yeah....I'd say that's about right. Puts it at the low end average 9'. (according to the chart in post #70) Some things easier, some things actually harder on mine to an average 9'er. Definitely tougher than other barboxes.
 

dr_dave

Instructional Author
Gold Member
Silver Member
Yeah....I'd say that's about right. Puts it at the low end average 9'. (according to the chart in post #70) Some things easier, some things actually harder on mine to an average 9'er.
I'm glad the number seems more reasonable now.

Definitely tougher than other barboxes.
No doubt about that!

Catch you later,
Dave
 

rexus31

AzB Silver Member
Silver Member
Here's the data on my friend's Gold Crown:

Table: 9' = 1
PSF: 4.25" = 1.10
PAF: 4", .25" difference = 1.0
PLF: 15/16" = 1.0

1 x 1.10 x 1 x 1 = 1.10

Although my table rates higher, I feel his table plays a bit tougher because of the speed of the cloth (Simonis 760, Tournament Blue) and the responsiveness of the cushions.
 

dr_dave

Instructional Author
Gold Member
Silver Member
Here's the data on my friend's Gold Crown:

Table: 9' = 1
PSF: 4.25" = 1.10
PAF: 4", .25" difference = 1.0
PLF: 15/16" = 1.0

1 x 1.10 x 1 x 1 = 1.10
I've added it to the list.

Although my table rates higher, I feel his table plays a bit tougher because of the speed of the cloth (Simonis 760, Tournament Blue) and the responsiveness of the cushions.
Some people might think of it the other way around, preferring a faster table with responsive cushions (requiring less work to get the CB around the table) ... right? Cloth speed and cushions responsiveness are definitely in the "qualitative" category that might be difficult to factor in logically and simply (with easy and reliable measurements or "judgements").

Thanks for the input.


Here's the current 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
example "B" -- 9':1.00 -- 3 7/8":1.20 -- 5/8":1.00 -- 1 7/8":1.03 -- 1.24
rexus31 -- 9':1.00 -- 4":1.20 -- 3/8":1.00 -- 1":1.00 -- 1.20
FatBoy -- 9':1.00 -- 4":1.20 -- 1/4":1.00 -- 1":1.00 -- 1.20
TATE -- 9':1.00 -- 4":1.20 -- 1/4":1.00 -- 7/8":1.00 -- 1.20
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
Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10 -- 1 7/8":1.03 -- 1.02
"standard" table -- 9':1.00 -- 4 9/16":1.00 -- 9/16":1.00 -- 1 5/8":1.00 -- 1.00 ("standard")
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")
 

Sloppy Pockets

AzB Silver Member
Silver Member
Here's the current updated list:


Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10 -- 1 7/8":1.03 -- 1.02


Dr. D., my pocket shelf is only 1 3/4" deep, not 1 7/8". The actual calculations according to your modified criteria are now:

8'+: 0.95 - 5": 0.95 - 1":1.10 - 1 3/4":1.0 - TDF = 0.99

Which seems right to me. Not real easy, not real tough. "Challenging" is a better description. Anyway, sorry for the confusion on the pocket shelf depth.

I like the way you keep tweaking things as recommendations come in. Optimizing generalized factors like this can take some time and a lot of thought, and they may not cover all tables or playing situations. Still, I think this will be a nice addition to the existing knowledge base. Keep up the good work. :smile:

BTW I just measured the down angles on my pockets facings, and it'd be generous to say they are 10º. With the acceptable standard being between 12º and 15º, this may be yet one more reason my pockets reject well-hit balls. I'm tired of the way they play. If I can't find someone to work on my table, I just may undertake the job myself.
 

dr_dave

Instructional Author
Gold Member
Silver Member
Dr. D., my pocket shelf is only 1 3/4" deep, not 1 7/8". The actual calculations according to your modified criteria are now:

8'+: 0.95 - 5": 0.95 - 1":1.10 - 1 3/4":1.0 - TDF = 0.99

Which seems right to me. Not real easy, not real tough. "Challenging" is a better description. Anyway, sorry for the confusion on the pocket shelf depth.
Thanks for the correction. I've change it (see below).


I like the way you keep tweaking things as recommendations come in. Optimizing generalized factors like this can take some time and a lot of thought, and they may not cover all tables or playing situations. Still, I think this will be a nice addition to the existing knowledge base. Keep up the good work. :smile:
This is not the best way to do it. It would be better to collect a bunch of data first and then correlate. But it has been fun, and it seems to be working a little better now.


BTW I just measured the down angles on my pockets facings, and it'd be generous to say they are 10º. With the acceptable standard being between 12º and 15º, this may be yet one more reason my pockets reject well-hit balls. I'm tired of the way they play. If I can't find someone to work on my table, I just may undertake the job myself.
Be careful. We don't want you to end up with "Sloppy Pockets." :grin-square:

Here's the latest:

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
example "B" -- 9':1.00 -- 3 7/8":1.20 -- 5/8":1.00 -- 1 7/8":1.03 -- 1.24
rexus31 -- 9':1.00 -- 4":1.20 -- 3/8":1.00 -- 1":1.00 -- 1.20
FatBoy -- 9':1.00 -- 4":1.20 -- 1/4":1.00 -- 1":1.00 -- 1.20
TATE -- 9':1.00 -- 4":1.20 -- 1/4":1.00 -- 7/8":1.00 -- 1.20
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")
 

Dopc

www.PoolActionTV.com
Silver Member
Thank you for your kind and encouraging feedback. I appreciate it.

I get the following:

Dopc -- 8':0.90 -- 4.5":1.05 -- 3/4":1.02 -- 1 1/4":1.00 -- 0.96

Please check me on this, being careful with the "<" and "<=" signs and the "If" clauses after the factor tables.

Thanks again,
Dave

Dr.Dave.
Thanks for the correction, advanced math isn't one of my strongest skills.

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.

A lot of assumption and guessing are involved. From what I've read, I believe the pockets are 4", with a throat not far off from that as well. Also, that post has a couple images of a pocket with balls.

In that post a few things are mentioned such as "push the facings back towards parallel so they're around 138 (rather than 141-142), and then ditch the shelf". And from the picture viewpoint, they sure did a good job of ditching it.

I hope this may offer some insight and wish I could be of more help.

Dopc.
 

JC

Coos Cues
Gold Member
Here are the three evolutions of my own GC in the dozen years I've had it. The center photo played much easier than it does now in the bottom photo although they would both rate "average" using this thread's formula.

 

cigardave

Who's got a light?
Silver Member
Sorry, I misinterpreted what "rail re-calibration" means. I'm obviously not a table mechanic. So, they re-calibrate the angle that the cushion back meets the sub-rail, if that is what I think you mean? That must be done to change the height of the cushion nose above the slate, right? Yeah, I can see why that would have no effect on the pocket mouth opening.
In essence, yes.

The only clarification I would make is they first take down the thickness of the subrails by 1/16" and then to get the nose of the cushion back up to where it belongs, they re-bevel the cushion attachment face by 3 degrees and then re-attach the cushions at the proper height above the slate.
 

Sloppy Pockets

AzB Silver Member
Silver Member
Here are the three evolutions of my own GC in the dozen years I've had it. The center photo played much easier than it does now in the bottom photo although they would both rate "average" using this thread's formula.

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.

And, yes, I'll bet they play real hard. ;)
 

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cigardave

Who's got a light?
Silver Member
Looks like you and I need to double-check our measurements because I'm the one that supplied Dave with the Diamond measurements and I doubt very much if Diamond has changed their slate or their pocket dimensions.

For example, I believe that it's well known that Diamond corner pockets are 4 1/2" at the throat yet you submitted a dimension of 4 1/8", which is a pretty big discrepancy. Re-check that, okay?

And I'll re-check the my measurement of the pocket shelf depth.
I just got done re-checking my table's (9' Diamond Pro Am) pocket shelf depth and have verified that it indeed is 1 3/4".

The method that I use was to lay a straight edge with some sighting-down depth (a level laying flat) with one side of the level intersecting both points of the cushions. Next, I laid a tape measure on the slate with the index on the edge of the slate at the centerline of the pocket and with the tape bisectinthe pocket's mouth. Next I sighted down from above with my eye looking down along the vertical face of the level to see where its projection of the planeof the level's vertical face intersects the tape measure... and it intersects it at 1.75"... the depth of the shelf as defined by Dr. Dave.

I'll post a photo when the pic on my smart phone posts automatically to my computer's Dropbox folder.
 
Last edited:

Sloppy Pockets

AzB Silver Member
Silver Member
In essence, yes.

The only clarification I would make is they first take down the thickness of the subrails by 1/16" and then to get the nose of the cushion back up to where it belongs, they re-bevel the cushion attachment face by 3 degrees and then re-attach the cushions at the proper height above the slate.

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.
 

JC

Coos Cues
Gold 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.

And, yes, I'll bet they play real hard. ;)

Good points. I suspected this table plays tougher than the formula rendered using my measurements. Donny terminated the facings there obviously to allow for a nice fit and finish of the pockets. Since it's behind the ledge it matters not for play. I believe the table has 143 degree pockets with about 14 degree down angle now. With the center photo the angle was about 138.
 
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