Table Difficulty Factor (TDF) for measuring table "toughness"
- Thread starter dr_dave
- Start date
Dave - I've got a 9' Diamond Pro Am with Pro Cut pockets.
I measured/calculated the following:
PMS 4.50"
PTS 3.75"
PMTD 0.75"
PSD 1.75"
TDF = 1.0 x 1.05 x 1.03 x 1.0 = 1.0815
Which is in the "tough" range... which I feel is appropriate.
Mine is the original "Red Diamond" version so I have the "BOINGY" cushions, which increases the table's "toughness" in my opinion to somewhere between tough and very tough.
I'm going to have my rails modified to the "Blue Diamond" version in the next month or thereabouts.
I measured/calculated the following:
PMS 4.50"
PTS 3.75"
PMTD 0.75"
PSD 1.75"
TDF = 1.0 x 1.05 x 1.03 x 1.0 = 1.0815
Which is in the "tough" range... which I feel is appropriate.
Mine is the original "Red Diamond" version so I have the "BOINGY" cushions, which increases the table's "toughness" in my opinion to somewhere between tough and very tough.
I'm going to have my rails modified to the "Blue Diamond" version in the next month or thereabouts.
i have this table as well-its in a studio in Vegas(i have since changed the rails, but it was a 07 red lable factory Diamond with the boingy rails). It is by the numbers we came up with today very close to what i posted earlier, however IMO its a much easier table than the GC with 3.99" openings. Much easier to run balls on this Diamond.
not a knock on Cigar's table, i love it!! just a observation cause i'm VERY familiar with it, i played 2+ years on mine. Then we changed the rails.
best
you will be much happier with the "Blue" rails, Greg really figured it out. He put lots of time and effort into it, he had help too. But I give all the guys credit at Diamond for the improvement they made. the Boing gets brutal sometimes.
I'd find it hard to believe that my table plays 15-20% harder in general than a standard Diamond table. I play on both, and they are pretty close in difficulty IMO. Both have their own unique set of challenges, and then it also depends heavily on your general style of play and the types of games you prefer to play.
Games like 14.1 are real nice to play on my table because most shots are hit softer and more straight into the lower corner pockets. Long, hard shots down the long rails are something I rarely do in 14.1. There usually is a better shot. In rotation games, there is no better shot to choose. You have to hit the next ball in order, and often have to hit it hard enough to get the CB back to the other end of the table for the next shot. There are also lots more combos and carom shots in 14.1, and the wider pocket openings are more forgiving of small miscalculations in these multi-ball shots. All told, I'd hazard a guess that a great 14.1 player like Schmidt or Harriman might actually find my table 15-20% easier for 14.1 than a standard Diamond with pro-cut pockets.
One other question that you or someone else might answer. Is the combined thickness of the cushion and the sub-rail to which it is attached a standard measurement? Mine are exactly 2" across, from the nose to the point where the feather cloth wraps around the feather strip. Anything that deviates from this size would have different pocket facing angles, even though the measurements at the pocket opening and the back of the throat are the same. I think it may be more accurate to specify the actual angles themselves. I measured mine very carefully using a small sliding bevel and a protractor. They are 144º, which is 3º more open than Diamond uses. Hit the ball hard down my rails and it better be 100% on or it will rattle out every time.
Several people have commented on the importance of cloth and ball conditions, cushion conditions, facing properties, humidity, etc.
I agree that these things, among many others, affect how a table actually "plays," but I don't think it is appropriate to include them in the table difficulty factor (TDF), which is based only on things related to the design/construction of the table that are easy to measure and relatively easy to characterize in a non-subjective way. But again, I agree that there are many other factors that come into play, many of which are unrelated to how the table was built.
FYI, here's a relevant sentence from the Table Difficulty Factor (TDF) document, and in the first post of the thread:
NOTE – The TDF and effective-score numbers should not be interpreted too literally since there are so many other factors that contribute to how difficult a table actually plays (cloth type and condition, ball conditions, pocket facing and shim properties, rail and cushion conditions, table levelness, humidity, etc.).
Thanks again to everybody for the input,
Dave
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Thank you for posting your table info and TDF calculation. I'm glad the result agrees with your perception.
Here's what we have so far:
Data reported by AZB users in decreasing order of table difficulty factor (TDF),
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":1.05 -- 1.26
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
cigardave -- 9':1.00 -- 4 1/2":1.05 -- 3/4":1.02 -- 1 3/4":1.00 -- 1.07
Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10-- 1 7/8":1.05 -- 1.04
"standard" table -- 9':1.00 -- 4 9/16":1.00 -- 9/16":1.00 -- 1 5/8":1.00 -- 1.00
SloMoHolic -- 9':1.00 -- 4 3/8":1.05 -- 5/8":1.00 -- 1 3/8":0.95 -- 1.00
12squared -- 9':1.00 -- 4 7/8":0.95 -- 3/4":1.02 -- 1 1/2":0.95 -- 0.92
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":0.95 -- 0.81
example "A" -- 8':0.90 -- 5":0.95 -- 1/2":0.98 -- 1 3/8":0.95 -- 0.80
Valley "bar box" -- 7':0.80 -- 4 1/2":1.05 -- 0":0.94 -- 3/4":0.90 -- 0.71
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Thanks for the input.
If you or others have specific recommendations for how the values for any of the factors should be changed in the different ranges, please let me know.
It sounds like you think the pocket size factor (PSF) for a 4" mouth should be greater than 1.20, and/or the value for a 4 1/2" mouth (1.05) should be lower. That seems like a tough sell to me. Or maybe you think one of the other factors should be changed.
Let me know.
Regards,
Dave
Please list the values for the two tables you are comparing and let's talk about how to change the factors to have them be more appropriate. It sounds like you are suggesting that the pocket shelf factor should be given more weight on the deep side.
I'm not claiming the system is good yet. That's why I posted the draft on AZB ... to get your input and make improvements.
Thanks,
Dave
Here's the current comparison of your table with the TDF "standard, based on the updated numbers:
Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10 -- 1 7/8":1.05 -- 1.04
"standard" table -- 9':1.00 -- 4 9/16":1.00 -- 9/16":1.00 -- 1 5/8":1.00 -- 1.00
Maybe what you are calling a "standard Diamond table" is also more difficult than the TDF "standard." Could you take some measurements and report the values to see how they compare? Thanks.
Those are all good points, but I don't think we should attempt to include things like "style of play" or "player ability level" in the table difficulty factor. Again, the purpose of the TDF is just to provide a general and approximate measure of comparison based strictly on the table and pocket geometry.
I agree that it would be better to measure the angle directly, but I didn't want to assume that a typical pool player will own an angle-measuring device (e.g., protractor) and be able to use it accurately. Most cushions are very close to 2" across and any difference won't have that big of an effect since the pocket-angle-factor is somewhat qualitative already (and apparently still needs some tweaking).
Thank you for the input,
Dave
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Dave - Out of curiosity, what are the measurements/calcs/factors of a standard 9' Gold Crown?
Is that your "standard" of a table having a TDF of 1... which is in the center of the "average" range?
Most of us are very familiar with a standard GC so that's why I asked the question.
Is that your "standard" of a table having a TDF of 1... which is in the center of the "average" range?
Most of us are very familiar with a standard GC so that's why I asked the question.
I don't know. I don't have one handy. Could someone post these if they plan to be near one soon?
I based the TDF=1 "standard" on the centers of the ranges of the WPA specs.
Good question.
Regards,
Dave
I just remembered that we have some Gold Crowns on the BU graduates list. Here's an example from 12squared:
9':1.00 -- 4 7/8":0.95 -- 3/4":1.02 -- 1 1/2":0.95 -- 0.92
This GC is about 8% easier than a WPA spec table.
I've added it to the 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":1.05 -- 1.26
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
cigardave -- 9':1.00 -- 4 1/2":1.05 -- 3/4":1.02 -- 1 3/4":1.00 -- 1.07
Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10-- 1 7/8":1.05 -- 1.04
"standard" table -- 9':1.00 -- 4 9/16":1.00 -- 9/16":1.00 -- 1 5/8":1.00 -- 1.00
SloMoHolic -- 9':1.00 -- 4 3/8":1.05 -- 5/8":1.00 -- 1 3/8":0.95 -- 1.00
12squared -- 9':1.00 -- 4 7/8":0.95 -- 3/4":1.02 -- 1 1/2":0.95 -- 0.92
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":0.95 -- 0.81
example "A" -- 8':0.90 -- 5":0.95 -- 1/2":0.98 -- 1 3/8":0.95 -- 0.80
Valley "bar box" -- 7':0.80 -- 4 1/2":1.05 -- 0":0.94 -- 3/4":0.90 -- 0.71
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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.
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.
Thanks for the data and input. I've added you to the list (see below). The current TDF system rates your table as 20% more difficult than the "standard" (which is more difficult than a GC). Could you send me measurements for a Diamond so I can add it to the list?
Thanks,
Dave
name -- TSF -- PSF -- PAF -- PLF -- TDF
example "B" -- 9':1.00 -- 3 7/8":1.20 -- 5/8":1.00 -- 1 7/8":1.05 -- 1.26
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
Sloppy Pockets -- 8'+:0.95 -- 5":0.95 -- 1":1.10-- 1 7/8":1.05 -- 1.04
"standard" table -- 9':1.00 -- 4 9/16":1.00 -- 9/16":1.00 -- 1 5/8":1.00 -- 1.00
SloMoHolic -- 9':1.00 -- 4 3/8":1.05 -- 5/8":1.00 -- 1 3/8":0.95 -- 1.00
12squared -- 9':1.00 -- 4 7/8":0.95 -- 3/4":1.02 -- 1 1/2":0.95 -- 0.92
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":0.95 -- 0.81
example "A" -- 8':0.90 -- 5":0.95 -- 1/2":0.98 -- 1 3/8":0.95 -- 0.80
Valley "bar box" -- 7':0.80 -- 4 1/2":1.05 -- 0":0.94 -- 3/4":0.90 -- 0.71
FYI, I've made some changes to the pocket shelf factor per the info below:
It didn't change things very much ... the changes just reduce the importance slightly and better deal with extreme cases. I don't mean to imply that shelf depth isn't important, especially for faster shots close to the rail; but remember, the table difficulty factor is an average measure for the wide range of shots that occur on a pool table (not just the ones where shelf depth is very important).
FYI, the Table Difficulty Factor (TDF) document has also been revised.
Here's the latest revised 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
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
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 think I'm done making changes for a while until we get much more data and input.
Thanks again for all who have and will submit data and share thoughts.
Regards,
Dave
It didn't change things very much ... the changes just reduce the importance slightly and better deal with extreme cases. I don't mean to imply that shelf depth isn't important, especially for faster shots close to the rail; but remember, the table difficulty factor is an average measure for the wide range of shots that occur on a pool table (not just the ones where shelf depth is very important).
FYI, the Table Difficulty Factor (TDF) document has also been revised.
Here's the latest revised 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
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
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 think I'm done making changes for a while until we get much more data and input.
Thanks again for all who have and will submit data and share thoughts.
Regards,
Dave
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Dr. Dave.
Thank you for everything you do for billiards knowledge, and thank you for making all of that knowledge open and freely available for all to see and learn from. I have spent countless hours studying your work and then moving it to the table for real world exercise and practice.
I have recently re-worked my table (new rubber, cloth and closed my buckets down a 1/2" to 4.5" See the link in my signature if interested). The table is not difficult but plays fair and true for it's limited size. Here are the results of my table which I believe to be spot-on to what I feel the playability factor of it is.
Here are the measurements I have.
pocket mouth = 4.5"
back of throat = 3.75"
Shelf depth = 1.25"
If I did things correctly, these are the results I come up with.
Connelly Kayenta 8ft table.
TSF = .90
PSF = 1.05
PAF = 1.08
PLF = .98
______________
TDF = 1.000188
Dr. Dave, again I want to thank you for all you do for this wonderful sport, and commend you for sharing it with all of man kind open and freely. I look forward to all of your future discoveries and shared knowledge.
Dopc.
Thank you for everything you do for billiards knowledge, and thank you for making all of that knowledge open and freely available for all to see and learn from. I have spent countless hours studying your work and then moving it to the table for real world exercise and practice.
I have recently re-worked my table (new rubber, cloth and closed my buckets down a 1/2" to 4.5" See the link in my signature if interested). The table is not difficult but plays fair and true for it's limited size. Here are the results of my table which I believe to be spot-on to what I feel the playability factor of it is.
Here are the measurements I have.
pocket mouth = 4.5"
back of throat = 3.75"
Shelf depth = 1.25"
If I did things correctly, these are the results I come up with.
Connelly Kayenta 8ft table.
TSF = .90
PSF = 1.05
PAF = 1.08
PLF = .98
______________
TDF = 1.000188
Dr. Dave, again I want to thank you for all you do for this wonderful sport, and commend you for sharing it with all of man kind open and freely. I look forward to all of your future discoveries and shared knowledge.
Dopc.
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
Here's everything to date:
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