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

dr_dave · Jun 22, 2013

dr_dave said:
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
cigardave -- 9':1.00 -- 4 1/2":1.05 -- 3/4":1.02 -- 1 3/4":1.00 -- 1.07
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
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
Neil -- 7':0.80 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":1.00 -- 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':0.80 -- 4 1/2":1.05 -- 0":0.94 -- 3/4":0.95 -- 0.75

I was hoping people would 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

Fatboy · Jun 22, 2013

TATE said:
My table is a Brunswick set up by Ernesto Dominguez with custom rails. Many tables set up by Ernesto are similar. 9' Table, 4" pocket opening, 3 3/4" at the back of the pocket, 7/8" shelf. Very similar to Fat Boy's specs.

In my opinion, the pocket opening size is a lot more important in table difficuly for most shots than cut angle or depth of shelf. The reason is the pocket opening requires a greater degree of accuracy and the pockets are far more difficult to cheat. Cut angles and depth of shelf can be adjusted to by shooting softly on rail shots.

I would say my table plays 25% more difficult than a Diamond. A standard Diamond seem like buckets to me. I adjust to the angle and deeper shelf by shooting rail shots a little softer.

yes thats correct Chris, Ernesto did mine as well, its a hair tighter than your table and every bit 25-30% harder than a factory Diamond "Red Lable", my pockets have a GC shelf and are a 1/16" looser than the BB table. Oscar said its harder than the BB table as did Ernesto because of the shelf. If it had a Diamond shelf, forget it-too difficult.

Chris is a strong player and triple knowledgeable and i'll roll with his opinion here.:smile:

cigardave · Jun 22, 2013

dr_dave said:
Could you send me measurements for a Diamond so I can add it to the list?

Thanks,
Dave

Dave - My table is a standard 9' Diamond with (standard) Pro Cut pockets. And you have my measurements.

The TDF is 1.07, which is 15% more difficult that a standard 9' Gold Crown, which seems right to me.

dr_dave · Jun 22, 2013

cigardave said:
Dave - My table is a standard 9' Diamond with (standard) Pro Cut pockets. And you have my measurements.

The TDF is 1.07, which is 15% more difficult that a standard 9' Gold Crown, which seems right to me.

Thanks for the info. I've added some table descriptors to the list for future reference:

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
cigardave -- 9':1.00 -- 4 1/2":1.05 -- 3/4":1.02 -- 1 3/4":1.00 -- 1.07 (typical 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':0.80 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":1.00 -- 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':0.80 -- 4 1/2":1.05 -- 0":0.94 -- 3/4":0.95 -- 0.75 (typical Valley/Dynamo "bar box")

Fatboy · Jun 22, 2013

cigardave said:
Dave - My table is a standard 9' Diamond with (standard) Pro Cut pockets. And you have my measurements.

The TDF is 1.07, which is 15% more difficult that a standard 9' Gold Crown, which seems right to me.

yup sounds rite to me as well:smile:

Qaddiction · Jun 22, 2013

TDF = TSF x PSF x PAF x PLF

TDF = 1.0 x 1.10 x 1.05 x .98 = 1.1319 = Tough

Table Size Factor - 9' Diamond Pro (red label) with recalibrated rails, Artemis rubber, and Tournament Blue 860HR cloth.
Pocket Size Factor - 4.125" Pocket Mouth.
Pocket Angle Factor - Mouth 4.125" - Throat 3.37" = .755".
Pocket Shelf Factor - 1 3/8"

Looks like my table plays "Tough". I better start practicing a lot more. I don't find it easy to run out consistently. Has the pocket shelf depth changed over the years on the Diamond tables? I noticed another Diamond table on the list that has 1 3/4" pocket shelf's.

rexus31 · Jun 23, 2013

I think there are other factors to consider when accounting for a table's overall toughness. We've overlooked the profile and type (brand, if you will) of cushion and the type of cloth; Simonis vs. other brands, if Simonis, 760 vs. 860, vs. 860HR, Tournament Blue (plays faster) vs. other colors. I have a buddy who has a very nice Gold Crown with 4.25" pockets and had his rails (artemis, K66 I believe) calibrated by Donny Wessels. Tournament Blue 760 is on the bed with 860 HR on the rails. Although his pockets are bigger than mine, I feel his table plays tougher because of the speed of the cloth and the responsiveness of the rails. Players are more likely to over run position on his table than any other I've played on. I'll see if we can get his specs and see how it ranks.

Is there a way for us to add Pocket Down Angle as a factor for those of us that know that spec? Maybe a separate equation (Standard vs. Advanced)? Maybe all the other specs I mentioned above could fall into an Advanced Measurement for those that know them.

cigardave · Jun 23, 2013

Qaddiction said:
TDF = 1.0 x 1.10 x 1.02 x .98 = 1.09956 = Tough

Table Size Factor - 9' Diamond Pro (red label) with recalibrated rails.
Pocket Size Factor - 4.125" Pocket Mouth.
Pocket Angle Factor - Mouth 4 1/8" - Throat 3 1/2" = 5/8".
Pocket Shelf Factor - 1 3/8"

Looks like my table plays "Tough". I better start practicing a lot more. I don't find it easy to run out consistently. Has the pocket shelf depth changed over the years on the Diamond tables? I noticed another Diamond table on the list that has 1 3/4" pocket shelf's.

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.

Sloppy Pockets · Jun 23, 2013

Qaddiction said:
Table Size Factor - 9' Diamond Pro (red label) with recalibrated rails.
Pocket Size Factor - 4.125" Pocket Mouth.
Pocket Angle Factor - Mouth 4 1/8" - Throat 3 1/2" = 5/8".
Pocket Shelf Factor - 1 3/8"

Has the pocket shelf depth changed over the years on the Diamond tables? I noticed another Diamond table on the list that has 1 3/4" pocket shelf's.

The re-calibrated rails on your table create pocket openings that are 3/8" tighter than the standard 4 1/2" Diamond pockets. As you reduce the pocket opening, the shelf depth also gets reduced as in the image below. The reduced pocket outline is shown in the thin black lines I added to Dave's drawing. You can see that a little bit of shimming can reduce the pocket shelf depth by a lot. This also narrows the pocket facing angle, which makes the pocket more accepting of hard hit balls.

dr_dave · Jun 23, 2013

Neil said:
... I don't think the system makes a fair correlation between table sizes.

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

dr_dave · Jun 23, 2013

Qaddiction said:
TDF = 1.0 x 1.10 x 1.02 x .98 = 1.09956 = Tough

Table Size Factor - 9' Diamond Pro (red label) with recalibrated rails.
Pocket Size Factor - 4.125" Pocket Mouth.
Pocket Angle Factor - Mouth 4 1/8" - Throat 3 1/2" = 5/8".
Pocket Shelf Factor - 1 3/8"

Looks like my table plays "Tough". I better start practicing a lot more. I don't find it easy to run out consistently. Has the pocket shelf depth changed over the years on the Diamond tables? I noticed another Diamond table on the list that has 1 3/4" pocket shelf's.

I get the following instead (but close enough):
Qaddiction -- 9':1.00 -- 4 1/8":1.10 -- 5/8":1.00 -- 1 3/8":1.00 -- 1.10

Please check again to make sure you agree with the numbers, being careful with the ">" and "<=" symbols and the "If" clauses below the factor tables.

Thank you for posting. 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
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
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")

cigardave · Jun 23, 2013

Sloppy Pockets said:
The re-calibrated rails on your table create pocket openings that are 3/8" tighter than the standard 4 1/2" Diamond pockets. As you reduce the pocket opening, the shelf depth also gets reduced as in the image below. The reduced pocket outline is shown in the thin black lines I added to Dave's drawing. You can see that a little bit of shimming can reduce the pocket shelf depth by a lot. This also narrows the pocket facing angle, which makes the pocket more accepting of hard hit balls.

SP - Great explanation for when a table mechanic extends the subrails but I believe not applicable for re-calibrated rails on a Diamond, which in effect, only rotates the cushions slightly relative the the subrails. That would not change the pocket throat or the pocket shelf dimension.

dr_dave · Jun 23, 2013

rexus31 said:
I think there are other factors to consider when accounting for a table's overall toughness. We've overlooked the profile and type (brand, if you will) of cushion and the type of cloth; Simonis vs. other brands, if Simonis, 760 vs. 860, vs. 860HR, Tournament Blue (plays faster) vs. other colors. I have a buddy who has a very nice Gold Crown with 4.25" pockets and had his rails (artemis, K66 I believe) calibrated by Donny Wessels. Tournament Blue 760 is on the bed with 860 HR on the rails. Although his pockets are bigger than mine, I feel his table plays tougher because of the speed of the cloth and the responsiveness of the rails. Players are more likely to over run position on his table than any other I've played on. I'll see if we can get his specs and see how it ranks.

Is there a way for us to add Pocket Down Angle as a factor for those of us that know that spec? Maybe a separate equation (Standard vs. Advanced)? Maybe all the other specs I mentioned above could fall into an Advanced Measurement for those that know them.

There are many factors we could add:

- pocket vertical (down) angle
- cloth speed (for rolling balls)
- cloth slickness (for sliding balls)
- cushion rebound efficiency
- cushion rebound angle flattening
- cushion slide and spin reaction
- pocket facing toughness
- humidity effects
- table levelness
- ball roundness and roll trueness
- CB/OB weight/size differences
- ball properties
- ability level of the player
- what type of game is being played
- etc!!!!

I've tried to limit the "table difficulty factor (TDF)" to only the things related to table and pocket geometry that can be easily and accurately measured by a typical pool player. The other things can be difficult to measure and/or difficult to characterize quantitatively (maybe because their effects aren't totally understood) and/or related to "conditions" that can change over time.

Regardless, the TDF approach can easily be expanded for any additional factors you or others want to include. That's the beauty of the percentage-factor-based approach.

I prefer to keep things as simple as possible for now. Even with just the four factors I've included already, it is still difficult to get consensus on the factor numbers and results. However, it seems like the current results are now in better agreement with what people think. But it is still a "work in progress."

I thank you and other for the input,
Dave

dr_dave · Jun 23, 2013

Sloppy Pockets said:
The re-calibrated rails on your table create pocket openings that are 3/8" tighter than the standard 4 1/2" Diamond pockets. As you reduce the pocket opening, the shelf depth also gets reduced as in the image below. The reduced pocket outline is shown in the thin black lines I added to Dave's drawing. You can see that a little bit of shimming can reduce the pocket shelf depth by a lot. This also narrows the pocket facing angle, which makes the pocket more accepting of hard hit balls.

Good illustration! Thank you for posting that.

Regards,
Dave

JC · Jun 23, 2013

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.

JC

BRussell · Jun 23, 2013

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

JC · Jun 23, 2013

Sloppy Pockets said:
The re-calibrated rails on your table create pocket openings that are 3/8" tighter than the standard 4 1/2" Diamond pockets. As you reduce the pocket opening, the shelf depth also gets reduced as in the image below. The reduced pocket outline is shown in the thin black lines I added to Dave's drawing. You can see that a little bit of shimming can reduce the pocket shelf depth by a lot. This also narrows the pocket facing angle, which makes the pocket more accepting of hard hit balls.

So you "shim up the pockets" to be able to tell the world about your bad ass tight table and in reality you made it easier to pocket balls that aren't gross misses. Actually this dynamic has been well know.

No wonder the pros like this configuration. An accurate shot plus an accepting pocket equals packages. An accurate shot with jinky pockets rattles balls unfairly. Run baby run!!

JC

Sloppy Pockets · Jun 23, 2013

cigardave said:
SP - Great explanation for when a table mechanic extends the subrails but I believe not applicable for re-calibrated rails on a Diamond, which in effect, only rotates the cushions slightly relative the the subrails. That would not change the pocket throat or the pocket shelf dimension.

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.

I was just assuming he measured his table carefully but had had his sub-rails lengthened in order to narrow the pockets mouths to 4 1/8" and then wanted to know where his deep shelves disappeared to. lol

Sloppy Pockets · Jun 23, 2013

dr_dave said:
Good illustration! Thank you for posting that.

Regards,
Dave

And thanks to Glen Hancock (Real King Cobra) for bringing an understanding of this phenomenon to this board more times than he should have had to.

I have come to feel that Diamond did a real good job with coming up with the ideal pockets dimensions and angles. They made them a little tougher for straight in shots, a little easier for rail shots, a little more forgiving of hard hit balls, and a general consistency and predictability between all shots. In pool, consistency + predictability = easier in my book.

I love to play on the 9' Diamonds at my local room, but they are 15 minutes away and cost $5.75/person/hour. Mine plays almost as nice, but the corners can be a cruel mistress when I hit the pocket facing on a hard shot. There are times I swear the balls have middle fingers that they flip to me as they sit there in the jaws, refusing to go down.

Sloppy Pockets · Jun 23, 2013

JC said:
So you "shim up the pockets" to be able to tell the world about your bad ass tight table and in reality you made it easier to pocket balls that aren't gross misses. Actually this dynamic has been well know.

No wonder the pros like this configuration. An accurate shot plus an accepting pocket equals packages. An accurate shot with jinky pockets rattles balls unfairly. Run baby run!!

JC

You got it! Don't forget, however, the general public will always admire players who give the appearance of higher skill, even if it's not true.

Notice how the Bonus Ball announcers keep going on and on about how tight the pockets on their Rasson tables are, when a Diamond Pro-Am with its deep pocket shelves and more open pocket facing angles would probably make the game harder... even with those 4 1/2" "buckets". I'm sure the public will eat this up because their heroes will seem even more superhuman because of the "extremely difficult" equipment they are forced to play on.

Don't expect the BB players to tell you this, though. They still miss balls, after all is said and done. Gotta blame it on something.

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

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