99 views

Skip to first unread message

Jun 6, 2023, 5:40:33 AMJun 6

to

After posting a response to BG-bzzt, I thought I

would spend some time keyword searching BGO.

BTW: I forgot the mention that 1-ply rollouts of

the Othello positions took about 20 minutes or

so. They go really fast. I didn't want to mislead

you guys to think that I spent a big effort...

Anyway, one of the articles I hit in BGO was from

just yesterday and its first two lines read as this:

"I also think match winning chance is an

"increasing function of match length for

"a certain PR difference.

"However, The PR itself is dependent on

"the match length.

It put a smug smirk on my face. ;) How many

times had I thought of you guys as circus dogs

chasing your tails or mathematicians/scientists

volunteering as clowns to entertain kids at county

fairs, etc. (hey why not? as long as there are no

laws against it, right?)

Instead of repeating my old arguments about

how you guys use circular logic and circular data

to prove yourselves right, I thought I would make

use of some puns like "circular circus" or such.

When I think that I may be coining a new, word,

expression or pun, I usually search for it on the

Internet to see if others had used it already.

Guess what? Doing a search for the exact words

"circular circus" found quite a few results... :(

It's in the "glossary of circus terminology" at

https://circushalloffame.com/glossary-of-circus-terminology/

There is even a web site by that name:

https://circular-circus.com/

But my usage of it would have been in a different

context than those, uniquely related to cube skill

theory, etc. in gamblegammon. :))

MK

would spend some time keyword searching BGO.

BTW: I forgot the mention that 1-ply rollouts of

the Othello positions took about 20 minutes or

so. They go really fast. I didn't want to mislead

you guys to think that I spent a big effort...

Anyway, one of the articles I hit in BGO was from

just yesterday and its first two lines read as this:

"I also think match winning chance is an

"increasing function of match length for

"a certain PR difference.

"However, The PR itself is dependent on

"the match length.

It put a smug smirk on my face. ;) How many

times had I thought of you guys as circus dogs

chasing your tails or mathematicians/scientists

volunteering as clowns to entertain kids at county

fairs, etc. (hey why not? as long as there are no

laws against it, right?)

Instead of repeating my old arguments about

how you guys use circular logic and circular data

to prove yourselves right, I thought I would make

use of some puns like "circular circus" or such.

When I think that I may be coining a new, word,

expression or pun, I usually search for it on the

Internet to see if others had used it already.

Guess what? Doing a search for the exact words

"circular circus" found quite a few results... :(

It's in the "glossary of circus terminology" at

https://circushalloffame.com/glossary-of-circus-terminology/

There is even a web site by that name:

https://circular-circus.com/

But my usage of it would have been in a different

context than those, uniquely related to cube skill

theory, etc. in gamblegammon. :))

MK

Jun 7, 2023, 5:00:14 AMJun 7

to

MK schrieb am Dienstag, 6. Juni 2023 um 11:40:33 UTC+2:

> "I also think match winning chance is an

> "increasing function of match length for

> "a certain PR difference.

If you throw a biased coin (lets say 0,52 head) you don't agree that the probability of winning betting on heads is a function of throwing the coin only once or best of 3 or best of 100?
> "I also think match winning chance is an

> "increasing function of match length for

> "a certain PR difference.

> "However, The PR itself is dependent on

> "the match length.

I'm to limited to draw from this the conclusion that this shows a circular argumentation.

Jun 7, 2023, 9:20:34 AMJun 7

to

On 6/7/2023 5:00 AM, Frank Berger wrote:

> MK schrieb am Dienstag, 6. Juni 2023 um 11:40:33 UTC+2:

>> "However, The PR itself is dependent on

>> "the match length.

> I have to commit that this sentence doesn't make much sense to me, maybe some context is missing.

The original poster said that he doesn't know his match
> MK schrieb am Dienstag, 6. Juni 2023 um 11:40:33 UTC+2:

>> "However, The PR itself is dependent on

>> "the match length.

> I have to commit that this sentence doesn't make much sense to me, maybe some context is missing.

equity table for longer matches.

I suspect that the effect of not knowing the MET is very small

in practice. But there could be other factors, such as fatigue

or loss of concentration, that could lead players to make more

mistakes in longer matches. Or, the correlation could go in

the opposite direction---maybe a player takes longer matches

more seriously and puts in more of an effort, but regards short

matches as being frivolous and not worthy of serious attention.

---

Tim Chow

Jun 7, 2023, 12:36:30 PMJun 7

to

On June 7, 2023 at 3:00:14 AM UTC-6, Frank Berger wrote:

> MK schrieb am 6. Juni 2023 um 11:40:33 UTC+2:

>> "I also think match winning chance is an

>> "increasing function of match length for

>> "a certain PR difference.

> If you throw a biased coin (lets say 0,52 head)

> you don't agree that the probability of winning

> betting on heads is a function of throwing the

> coin only once or best of 3 or best of 100?

Sure but the question is how did you determine

that the coin is 52% biased in the first place..?

Did it take you only 1 throw, 3 throws, 100 throws

to realize that it was 52% biased for for heads..?

>> "However, The PR itself is dependent on

>> "the match length.

> I have to commit that this sentence doesn't make

> much sense to me, maybe some context is missing.

> What might be meant is that the longer the match

> is, the higher the probability is that the measured

> PR is close to the real PR.

This is just the point. If the formula was correct, the

actual/estimated PRs would be accurate across all

match lengths.

> One medium error in a 1-pointer ruins your PR

> whereas in a 25-pointer it hasn't much influence.

> This is true (and rather trivial)

You are pointing out a problem with PR calculation

but why are you trivializing? Can't you face reality?

> I'm to limited to draw from this the conclusion that

> this shows a circular argumentation.

PR is based on lost equity, no? And how is equity

calculated? In "Match Equity Tables" for example?

I think it's rather easy to see the circularity...

MK

> MK schrieb am 6. Juni 2023 um 11:40:33 UTC+2:

>> "I also think match winning chance is an

>> "increasing function of match length for

>> "a certain PR difference.

> If you throw a biased coin (lets say 0,52 head)

> you don't agree that the probability of winning

> betting on heads is a function of throwing the

> coin only once or best of 3 or best of 100?

that the coin is 52% biased in the first place..?

Did it take you only 1 throw, 3 throws, 100 throws

to realize that it was 52% biased for for heads..?

>> "However, The PR itself is dependent on

>> "the match length.

> I have to commit that this sentence doesn't make

> much sense to me, maybe some context is missing.

> What might be meant is that the longer the match

> is, the higher the probability is that the measured

> PR is close to the real PR.

actual/estimated PRs would be accurate across all

match lengths.

> One medium error in a 1-pointer ruins your PR

> whereas in a 25-pointer it hasn't much influence.

> This is true (and rather trivial)

but why are you trivializing? Can't you face reality?

> I'm to limited to draw from this the conclusion that

> this shows a circular argumentation.

calculated? In "Match Equity Tables" for example?

I think it's rather easy to see the circularity...

MK

Jun 7, 2023, 2:14:42 PMJun 7

to

On June 7, 2023 at 7:20:34 AM UTC-6, Timothy Chow wrote:

> The original poster said that he doesn't know

> his match equity table for longer matches.

> I suspect that the effect of not knowing the

> MET is very small in practice.

And I think it can go both was also like other
> The original poster said that he doesn't know

> his match equity table for longer matches.

> I suspect that the effect of not knowing the

> MET is very small in practice.

factors you mentioned below.

> But there could be other factors, such as .....

Sure but finding an explanation for it doesn't

change the fact observed.

I went back and read the entire thread. Quite

interesting. It's good to see that some people

disturb the comfort of concensus in BGO, of

all places :) which seem to be official "whore

house" of gamblegammon. Maybe I'll visit the

bordello more often looking to find occasional

virgin ideas... ;)

In several posts, there were interesting remarks

that I feel like commenting on.

In your initial post, you say: "It doesn't seem

possible that winning probability can be totally

independent of match length, but I'm willing to

believe that it increases more slowly". I agree

looking at it from a different angle. As I had

pointed out many times in the past, doubling

cube shortens matches. A 13 or a 17 point

gamblegammon match may be equivalent of

a 5 point backgammon match, similarly a 19

or 25 point gamblegammon match may be

equivalent of a 7 point backgammon match.

(I'm just guesstimating.)

I don't know if it happens so in real life but in

theory the longer the match the higher the cube

can go, causing the "actual lengths of matches",

(measured in terms of games, not points), to

"increase more slowly" (borrowing your words).

Art Grater explains that Kaufmann created the

ELO for gamblegammon by modifying the ELO

for chess, (i.e. replacing D/400 by D times the

square root of N/2000). The problem goes back

to that. Since my first days on FIBS in 1997, I

always objected to it and called it a horse-fart

based on arbitrary constant. I'm glad to see it

being questioned so many years later.

It's good to see that in another of your posts

you admit: "The conventional formula with a

square root of N doesn't seem to be very well

founded, either theoretically or empirically". :)

Better late than never but so what...? I doubt

that it will be amended. And nor for lack of will

but for lack of knowing how to.

In the same post you ask: "The real question is

how quickly the match-winning chances increase

with match length". I couldn't guess how quicky

but in my opinion it will increase more smoothly

and steadily in backgammon, more erratically in

gamblegammon (because of the overestimated

"cube skill" fantasy).

In his long article where he says a lot without

saying anything new, the only thing interesting

suggestion Bob Koca makes is using 19,000

matches from other sources like dailygammon;

to which you respond by suggesting instead "a

bunch of bot-versus-bot games where random

noise is added to simulate different playing

strengths" and ask "if anyone has done that?".

If you remember, I had done something similar

and had reported on in RGB. I ran two sets of

games, one with players of equal checker skill

but very unequal cube skill, and one with players

of equal cube skill but very unaqual checker skill.

I was trying to show cube skill didn't matter as

much as checker skill but you can do a similar

experiment for your purposes.

For example, you can run cubeful and cubeless

matches between unequal players to see if the

winning probability does indeed increase more

slowly because of the cube. You an also do the

same experiment between equal players to see

if the winning probability stays the same as it

should, regardless of the cube or not.

This is all from me on this for now. I'll be very

curious to see what, if anything, will come out

of this discussion on BGO and/or here in RGB..??

MK

Jun 7, 2023, 6:46:23 PMJun 7

to

MK schrieb am Mittwoch, 7. Juni 2023 um 18:36:30 UTC+2:

> This is just the point. If the formula was correct, the

> actual/estimated PRs would be accurate across all

> match lengths.

Then throwing a coin 2 times, 4 times 8, 16, 1026 etc. has alway come up with 0.5 heads? Then e.g. a 3-PR player to make an equivalent error in any subset of games. I recommend you to watch a UBC match with real time analysis. Or throw coin and count.
> This is just the point. If the formula was correct, the

> actual/estimated PRs would be accurate across all

> match lengths.

>Sure but the question is how did you determine

>that the coin is 52% biased in the first place..?

MK: how can you be sure that you have an A?

A typical MK answer.

Jun 7, 2023, 8:21:15 PMJun 7

to

On June 7, 2023 at 4:46:23 PM UTC-6, Frank Berger wrote:

> MK schrieb am 7. Juni 2023 um 18:36:30 UTC+2:

>> This is just the point. If the formula was correct,

>> the actual/estimated PRs would be accurate

>> across all match lengths.

> Then throwing a coin 2 times, 4 times 8, 16, 1026

> etc. has alway come up with 0.5 heads?

Frank, I'm sorry :(, but frankly :), I have difficulty in

understanding what you write and I'm doing very

badly at communicating my thoughts also... :(

So let me try again. Instead of my badly botched

sentence above, I meant to say: If the formula was

correct, estimated match winning chances based

on PR difference would be accurate, (i.e. the same

as actual winning resuls), across all match lengths.

So, ignoring your last question above and going

back to your previous question with 52% bias, I

had agreed with you but actually wrongly because

you wouldn't win increasingly more than 52% if

you kept tossing the coind more times.

But in gamblegammon, the same PR difference is

expected to win more at an increasing rate as the

lengths of matches increase. And the issue that

Tim raised in his BGO thread is that actual results

of the 19,000 matches showed that the stronger

player didn't win increasingly more in increasingly

longer matches, as predicted/estimated.

Your coin toss example didn't apply to the subject

on hand at all. (That's why I'm always against using

stupid coin toss, etc. examples in trying to explain

backgammon or gamblegammon :) Are we clear

thus far on this now?

>> Sure but the question is how did you determine

>> that the coin is 52% biased in the first place..?

> F: Given A then B follows because of...

> MK: how can you be sure that you have an A?

> A typical MK answer.

Let me explain this also. Originally I had quoted

two sentences. Your question with 52% bias was

in relation to the first sentence and you omitted

the second one which was the one that created

the circularity by saying: "However, The PR itself

indicating to you, in a question format, that you

needed to somehow calculate/derive your 52%

from number of coin tosses, (i.e. match lengths),

instead of just pulling it out of the air. Otherwise,

there is no circularity and it's no wonder that you

don't see a circularity... I hope we are now clear

on this also?

MK

> MK schrieb am 7. Juni 2023 um 18:36:30 UTC+2:

>> This is just the point. If the formula was correct,

>> the actual/estimated PRs would be accurate

>> across all match lengths.

> Then throwing a coin 2 times, 4 times 8, 16, 1026

> etc. has alway come up with 0.5 heads?

understanding what you write and I'm doing very

badly at communicating my thoughts also... :(

So let me try again. Instead of my badly botched

sentence above, I meant to say: If the formula was

correct, estimated match winning chances based

on PR difference would be accurate, (i.e. the same

as actual winning resuls), across all match lengths.

So, ignoring your last question above and going

back to your previous question with 52% bias, I

had agreed with you but actually wrongly because

you wouldn't win increasingly more than 52% if

you kept tossing the coind more times.

But in gamblegammon, the same PR difference is

expected to win more at an increasing rate as the

lengths of matches increase. And the issue that

Tim raised in his BGO thread is that actual results

of the 19,000 matches showed that the stronger

player didn't win increasingly more in increasingly

longer matches, as predicted/estimated.

Your coin toss example didn't apply to the subject

on hand at all. (That's why I'm always against using

stupid coin toss, etc. examples in trying to explain

backgammon or gamblegammon :) Are we clear

thus far on this now?

>> Sure but the question is how did you determine

>> that the coin is 52% biased in the first place..?

> F: Given A then B follows because of...

> MK: how can you be sure that you have an A?

> A typical MK answer.

two sentences. Your question with 52% bias was

in relation to the first sentence and you omitted

the second one which was the one that created

the circularity by saying: "However, The PR itself

is dependent on the match length".

So, I added back circularity to your example by
indicating to you, in a question format, that you

needed to somehow calculate/derive your 52%

from number of coin tosses, (i.e. match lengths),

instead of just pulling it out of the air. Otherwise,

there is no circularity and it's no wonder that you

don't see a circularity... I hope we are now clear

on this also?

MK

Jun 8, 2023, 9:02:32 AMJun 8

to

On 6/7/2023 2:14 PM, MK wrote:

> Art Grater explains that Kaufmann created the

> ELO for gamblegammon by modifying the ELO

> for chess, (i.e. replacing D/400 by D times the

> square root of N/2000). The problem goes back

> to that. Since my first days on FIBS in 1997, I

> always objected to it and called it a horse-fart

> based on arbitrary constant. I'm glad to see it

> being questioned so many years later.

I'm sure you raised doubts about it many years before I did,
> Art Grater explains that Kaufmann created the

> ELO for gamblegammon by modifying the ELO

> for chess, (i.e. replacing D/400 by D times the

> square root of N/2000). The problem goes back

> to that. Since my first days on FIBS in 1997, I

> always objected to it and called it a horse-fart

> based on arbitrary constant. I'm glad to see it

> being questioned so many years later.

but this is far from the first time I've expressed doubts about

it. See for example:

https://www.bgonline.org/forums/webbbs_config.pl?read=182417

---

Tim Chow

Jun 8, 2023, 9:12:31 AMJun 8

to

MK <mu...@compuplus.net> writes:

> doubling cube shortens matches

Not that much, see

https://www.bkgm.com/rgb/rgb.cgi?view+712

... but it increases the number of skillful decisions by at least 50 per

cent, so easily compensates for the smaller number of checker moves.

> For example, you can run cubeful and cubeless matches between unequal

> players to see if the winning probability does indeed increase more

> slowly because of the cube.

I have not varied the match length, but done something similar:

10 matches to 64 points, "Expert" versus "Casual player" on GNU

Backgammon. 1 batch of 10 matches cubeless, 1 batch of 10 matches

cubeful.

The expert won all 20 matches. The casual players on average won 10.2

points in the cubeful matches, but 18.3 points in the cubeless matches.

To me this seems like a cube-skillful expert gardener cutting back the

lucky branches of the wildly growing new plant.

It is easy to confirm, try it yourself.

Best regards

Axel

> doubling cube shortens matches

Not that much, see

https://www.bkgm.com/rgb/rgb.cgi?view+712

... but it increases the number of skillful decisions by at least 50 per

cent, so easily compensates for the smaller number of checker moves.

> For example, you can run cubeful and cubeless matches between unequal

> players to see if the winning probability does indeed increase more

> slowly because of the cube.

10 matches to 64 points, "Expert" versus "Casual player" on GNU

Backgammon. 1 batch of 10 matches cubeless, 1 batch of 10 matches

cubeful.

The expert won all 20 matches. The casual players on average won 10.2

points in the cubeful matches, but 18.3 points in the cubeless matches.

To me this seems like a cube-skillful expert gardener cutting back the

lucky branches of the wildly growing new plant.

It is easy to confirm, try it yourself.

Best regards

Axel

Jun 8, 2023, 1:50:09 PMJun 8

to

Another three batches, this time a money session, stopped when the

expert reached 1000 points.

1. The casual player got 321 points when played cubeless (no cube skill

involved). This is the base case.

Now two batches played with the cube:

2. When the casual checker play was combined with expert cube handling,

the casual player got 312 points, which is very similar to the base

case. As before, the size of the big win by the expert resulted only

from the checker play, since both players handled the cube expertly

(in contrast to "not at all" in case 1).

3. When the casual checker play was combined with cube handling set to

"Casual Player", the casual player reached only 103 points.

I would think that the much increased margin of the expert's win may

safely be called "cube skill".

But for sure I will be told here (not: "learn") what I did wrong.

Best regards

Axel

expert reached 1000 points.

1. The casual player got 321 points when played cubeless (no cube skill

involved). This is the base case.

Now two batches played with the cube:

2. When the casual checker play was combined with expert cube handling,

the casual player got 312 points, which is very similar to the base

case. As before, the size of the big win by the expert resulted only

from the checker play, since both players handled the cube expertly

(in contrast to "not at all" in case 1).

3. When the casual checker play was combined with cube handling set to

"Casual Player", the casual player reached only 103 points.

I would think that the much increased margin of the expert's win may

safely be called "cube skill".

But for sure I will be told here (not: "learn") what I did wrong.

Best regards

Axel

Jun 8, 2023, 11:10:13 PMJun 8

to

On June 8, 2023 at 7:02:32 AM UTC-6, Timothy Chow wrote:

> On 6/7/2023 2:14 PM, MK wrote:

>> ..... Since my first days on FIBS in 1997, I
> On 6/7/2023 2:14 PM, MK wrote:

>> always objected to it and called it a horse-fart

> > based on arbitrary constant. I'm glad to see it

> > being questioned so many years later.

Small but important correction: I meant to type
> > based on arbitrary constant. I'm glad to see it

> > being questioned so many years later.

"constants" in plural, as there more than one in

the formula and that I objected to them all!

> I'm sure you raised doubts about it many years

> before I did, but this is far from the first time

> I've expressed doubts about it. See for example:

> https://www.bgonline.org/forums/webbbs_config.pl?read=182417

way match length enters that formula" is a much

"timid" (pun intended ;) expression of a doubt but

I'll say fair enough.

However, I don't understand what you are trying to

get at when you ask Maik: "Are you saying that the

dependence on match length in that formula is

surprisingly simple?" and add: "I have *also* had..."

indicating that you *also* think it's "...surprisingly

simple"; and then asking him another question: "Or

are you saying that the concept of "backgammon

skill" is too complex a concept to be captured by a

single number?".

I really couln't understand his response to you and

you haven't said anything more to clearly indicate

your stance. Would you mind explaining now?

To expand on what I said in a previous response to

you in this thread: A single number may work well

enough for backgammon but not gamblegammon.

A 5-point backgammon match can't last less than

3 games, (i.e. 2 gammons + 1 single win vs. 0), or

more than 9 games, (i.e. 5 single wins vs. 4 single

wins). The numbers for a 7-point match are 4 and

13 respectively.

In contrast, a 15-point gamblegammon match can

be over in 1 game, (i.e. 1 single win with 16 cube or

1 gammon or backgammon win with 8 cube vs. 0),

or last 29 games, (i.e. 15 single wins vs. 14 single

wins). The numbers for a 25-point match are again

1 and 49 respectively.

In backgammon, the minimum number of games

in matches do "necessarily" increase as the match

lengths increase but not in gamblegammon where

a match of any length can be over in one game.

In backgammon, different formulas for different

match lengths can also work and perhaps better.

I'm glad I'm not a mentally ill gambler mathematician

facing the task of concocting different formulas for

different match lengths or to come with other ways

of solving the problem...

BTW: I found some really good, long threads on the

issue from 1998, that I had initiated and attracted

lengthy articles from many RGB heavy-weights of

that era when ideas hadn't petrified, people weren't

indogtrained yet. I printed them into PDF's and may

share them with comments if/when I find the time.

Just to give you a taste, here are two litle snippets.

Among my suggestions was different rating formulas

for "lackgammon" (the name I coined for 1-pointers

without gammon wins), backgammon (the real thing)

and "jackgammon" (the name I coined for cubeful play).

I was sooo ahead of my time... :)

And below is a long quote that Tim may really like, (the

last sentence of which was "music to Murat's ears"... :)

MK

===========================================

Posted by Jim Williams on Oct 21, 1998.

This touches on a question I have been evaluating. I am suspicious of

the fibs rating forumla in the way it accounts for match length. I have

collected a lot of match results and checked empirically whether the

winning probability as predicted by the FIBS rating formula actually

matches the observed winning probability for a given match between

players

of known ratings. I sampled the players ratings before recording any

matches so that the random errors in the ratings would be uncorrelated

with with the outcome of the observed games. Only matches where both

players had at least 1000 experience points were included. Currently

the number of recorded results is as follows:

1 point matches 19926

3 point matches 12036

5 point matches 8621

1, 3, and 5 account for 90% of all matches.

I then took the fibs ratings formula for win probability:

P = 1/(1 + 10^(D*sqrt(N)/2000))

Rather than using the match length for N, I used an effective

match length where the effective match length was chosen so

that the formula gave the best fit with the observed data.

The results were what I expected only more extreme. The effective

match lengths which gave the best fit were as follows:

match length effective match length

---------------------------------------------------------

1 1.6

3 1.6

5 2.1

Due to the limited number of matches recorded, the standard error

on these effective match lengths is about 0.25 . If anyone notices

zbest lurking on fibs, he is collecting more data to try to get

a more accurate fix on these numbers.

These numbers suggest that a 3 point match has exactly the same

skill component as a 1 point match, and a 5 point match only

slightly more.

I am at a loss to explain these numbers, but the implication is

that if you want to increase you rating, play 1 point matches

agains the weakest opponents you can find, and play long matches

against the strongest opponents you can find. It also suggests

that if we want to make backgammon more a game of skill and less

a game of luck, we should eliminate the doubling cube.

===========================================

Jun 9, 2023, 12:24:18 AMJun 9

to

On June 8, 2023 at 7:12:31 AM UTC-6, Axel Reichert wrote:

> MK <mu...@compuplus.net> writes:

>> doubling cube shortens matches

> Not that much, see

> https://www.bkgm.com/rgb/rgb.cgi?view+712

The stats there show average number of games
> MK <mu...@compuplus.net> writes:

>> doubling cube shortens matches

> Not that much, see

> https://www.bkgm.com/rgb/rgb.cgi?view+712

in matches to be 24-48% less than match lengths.

If they were meaningful, I would say that they are

a little more than what you call "not that much" but

without comparing to average games in cubeless

matches, they are useless in telling how much the

cube shortens matches.

> ... but it increases the number of skillful

> decisions by at least 50 per cent,

> so easily compensates for the smaller

> number of checker moves.

>> For example, you can run cubeful and cubeless

>> matches between unequal players to see if the

>> winning probability does indeed increase more

>> slowly because of the cube.

> I have not varied the match length, but done

> something similar:

irrelevant to this discussion but let's hear it anyway.

> 10 matches to 64 points, "Expert" versus "Casual

> player" on GNU Backgammon. 1 batch of 10

> matches cubeless, 1 batch of 10 matches cubeful.

the same thing as "isolating the cube skill"..!

Thus only cubeful play can be used to isolate and

demontrate cube skill vs no cube skill.

> The casual players on average won 10.2 points

> in the cubeful matches, but 18.3 points in the

> cubeless matches.

matches either.

> To me this seems like a cube-skillful expert

> gardener cutting back the lucky branches

apples and pears at the same and arriving at

some wishful conclusions... :(

> It is easy to confirm, try it yourself.

experiment to arrive at the same results?? No,

thanks. I'll take your word for it... ;)

MK

Jun 9, 2023, 12:48:53 AMJun 9

to

On June 8, 2023 at 11:50:09 AM UTC-6, Axel Reichert wrote:

> Axel Reichert <ma...@axel-reichert.de> writes:

> I would think that the much increased

> margin of the expert's win may safely

> be called "cube skill".

Okay, this is better.

> But for sure I will be told here (not:

> "learn") what I did wrong.

Not but I don't understand is what were

you trying to prove at the expense of

derailing/hikacking this thread?

Even as I call it "bullshit", I never argued

that there wasn't any cube skill at all.

I have and I continue to argue that it is

way too exaggerated and misassessed

by the bots because of some jackoffski

formula, circular MET's, etc.

So, really, what have you accomplished??

MK

> Axel Reichert <ma...@axel-reichert.de> writes:

> I would think that the much increased

> margin of the expert's win may safely

> be called "cube skill".

> But for sure I will be told here (not:

> "learn") what I did wrong.

you trying to prove at the expense of

derailing/hikacking this thread?

Even as I call it "bullshit", I never argued

that there wasn't any cube skill at all.

I have and I continue to argue that it is

way too exaggerated and misassessed

by the bots because of some jackoffski

formula, circular MET's, etc.

So, really, what have you accomplished??

MK

Jun 9, 2023, 9:14:39 AMJun 9

to

On 6/8/2023 11:10 PM, MK wrote:

> I really couln't understand his response to you and

> you haven't said anything more to clearly indicate

> your stance. Would you mind explaining now?

The reason I wasn't clear is that I didn't---and still
> I really couln't understand his response to you and

> you haven't said anything more to clearly indicate

> your stance. Would you mind explaining now?

don't---have well-developed ideas of my own on the subject.

> To expand on what I said in a previous response to

> you in this thread: A single number may work well

> enough for backgammon but not gamblegammon.

rapid, and blitz, because people have made the judgment call

that the different time controls make enough of a difference

to call it a different game.

Are you suggesting, perhaps, that if we were to maintain

separate Elo ratings for different match lengths, then for

cubeless backgammon, players' Elo ratings would be pretty

much the same for all match lengths, but that with the cube,

their Elo ratings might not correlate very well? Player A

might be significantly better against Player B in a 5-point

match, but significantly worse in an 11-point match?

---

Tim Chow

Jun 12, 2023, 7:51:50 AMJun 12

to

Axel Reichert <ma...@axel-reichert.de> writes:

> Another three batches, this time a money session, stopped when the

> expert reached 1000 points.

>

> 1. The casual player got 321 points when played cubeless (no cube skill

> involved). This is the base case.

>

> Now two batches played with the cube:

>

> 2. When the casual checker play was combined with expert cube handling,

> the casual player got 312 points, which is very similar to the base

> case. As before, the size of the big win by the expert resulted only

> from the checker play, since both players handled the cube expertly

> (in contrast to "not at all" in case 1).

>

> 3. When the casual checker play was combined with cube handling set to

> "Casual Player", the casual player reached only 103 points.

>

> I would think that the much increased margin of the expert's win may

> safely be called "cube skill".

And in order to get a result as bad as in case 3, you need to set the
> Another three batches, this time a money session, stopped when the

> expert reached 1000 points.

>

> 1. The casual player got 321 points when played cubeless (no cube skill

> involved). This is the base case.

>

> Now two batches played with the cube:

>

> 2. When the casual checker play was combined with expert cube handling,

> the casual player got 312 points, which is very similar to the base

> case. As before, the size of the big win by the expert resulted only

> from the checker play, since both players handled the cube expertly

> (in contrast to "not at all" in case 1).

>

> 3. When the casual checker play was combined with cube handling set to

> "Casual Player", the casual player reached only 103 points.

>

> I would think that the much increased margin of the expert's win may

> safely be called "cube skill".

checker play to have a noise of about 0.1 (casual player has a noise of

0.05). With this noise used in a cubeless session or with expert cube

handling in a cubeful session, you will get roughly the same defeat

(1000 points for the expert, 100 point for the clueless).

The difference between 0.05 noise and 0.1 noise is HUGE, even "Beginner"

has only 0.06 noise. Imagine every checker play on average being a

whopper.

Axel

Jun 12, 2023, 7:56:59 AMJun 12

to

[Cube use]

>> ... but it increases the number of skillful

>> decisions by at least 50 per cent,

>

> Who says?

Easy to see:

Imagine the cube staying in the middle for the whole game. Then

obviously the number of decisions has doubled ("every roll is a cube

decision"). If the cube is turned at first opportunity (and then maybe

used later or not, does not matter), then only the cube owner has an

additional cube decision, which amounts to 50 per cent more decisions.

Axel

>> ... but it increases the number of skillful

>> decisions by at least 50 per cent,

>

> Who says?

Imagine the cube staying in the middle for the whole game. Then

obviously the number of decisions has doubled ("every roll is a cube

decision"). If the cube is turned at first opportunity (and then maybe

used later or not, does not matter), then only the cube owner has an

additional cube decision, which amounts to 50 per cent more decisions.

Axel

Jun 13, 2023, 12:41:51 AMJun 13

to

On June 9, 2023 at 7:14:39 AM UTC-6, Timothy Chow wrote:

> On 6/8/2023 11:10 PM, MK wrote:

>> I really couln't understand his response to you and

>> you haven't said anything more to clearly indicate

>> your stance. Would you mind explaining now?

> The reason I wasn't clear is that I didn't---and still

> don't---have well-developed ideas of my own on

> the subject.

Ah, okay. No problem. Keep contributing if/when you
> On 6/8/2023 11:10 PM, MK wrote:

>> I really couln't understand his response to you and

>> you haven't said anything more to clearly indicate

>> your stance. Would you mind explaining now?

> The reason I wasn't clear is that I didn't---and still

> don't---have well-developed ideas of my own on

> the subject.

come up with new ideas, well-developed or not.

>> To expand on what I said in a previous response to

>> you in this thread: A single number may work well

>> enough for backgammon but not gamblegammon.

> Are you suggesting, perhaps, that if we were to

> maintain separate Elo ratings for different match

> lengths, then for cubeless backgammon, players'

> Elo ratings would be pretty much the same for all

> match lengths, but that with the cube, their Elo

> ratings might not correlate very well?

Yes, I am suggesting that it would be so but I am not
> maintain separate Elo ratings for different match

> lengths, then for cubeless backgammon, players'

> Elo ratings would be pretty much the same for all

> match lengths, but that with the cube, their Elo

> ratings might not correlate very well?

suggesting that it should be done so. I am confident

that given a sufficient amount of emprical data, any

competent mathematician can derive a single formula

that would work for all bacgammon/gamblegammon

matches of all lengths. It would help if the data is as

unbiased as possible but "understanding the data" is

the more imprtant.

What I meant above is that any such attempted rating

formula, (which we should stop referring to as "ELO"),

would better tolerate biased data in backgammon than

in gamblegammon because there is less "amount of"

and less "fluctuation of" luck without the doubling cube.

See my "Where there is no luck, there is no cube skill"

thread"

https://groups.google.com/g/rec.games.backgammon/c/TD3K--EK1cc/m/zGWh9J-FAgAJ

Thus, in gamblegammon, calculating the probability of

winning becomes calculating the probability of getting

lucky, because luck increases faster than skill as match

length increases.

I could see that cube magnified luck the moment I was

introduced to it and I categorically objected to an "ELO"

adapted from chess, (a game of skill), to backgammon,

(already a game of luck without the doubling cube and

even more so with it in gamblegammon), especially also

because of more than one arbitrary constant in the formula.

Soon after, in 1998, I had initiated discussions about it

and proposed a simple dynamic brackets system (that

we can discuss separately if there is an interest). What I

quoted from Jim Williams was from one of my threads

titled: "FIBS formula question/comment"

https://groups.google.com/g/rec.games.backgammon/c/2fCYjYSo9Ts/m/9EAZxznAFm8J

Another one of my threads on the same subject, from

around the same time is: "Rating system suggestions"

https://groups.google.com/g/rec.games.backgammon/c/qJ8T-0lJKz4/m/M61_5MEmvT4J

Many articles from these threads, (as from many others),

are individually, (thus improperly), quoted at "bkgm.com",

etc. without links to the threads they are taken from, which

leads to a loss of context. Anyone who can spare the time

may want to read the entire threads, as they contain many

other valuable posts from other, people, (even if they may

be less respected by the "incestuous circle").

Since I didn't believe in "fixing" the FIBS ELO at the time, I

didn't pay much attention to things like what Jim Williams

had written. What a novel idea his "effective match length"

was. Unfortunately, nobody else had picked up on it either

(his usage of the expressions was the first and only time

in RBG in all those 25 years). It is almost exactly what I was

trying to explain here a few days ago, (i.e. cube shortens

matches).

Since then, mentalli ill gambler mathematicians blamed it

on the inferior quality of the empirical data that was taken

from FIBS, maintaining that the formula would be accurate

if applied to "perfectly" played matches between bots. 25

years later, Bob Koca wonders if it may works better using

data taken from "cleaner sources like Gailygammon". What

if it does not? Will he, et al., shove it up their stuffy noses?

25 years later, you are still asking if anyone has done any

bot-vs-bot experiments... Why weren't they done? Perhaps

for fear of discovering the ugly reality that you all couldn't

face? How much more time is needed to see one inch of

progress made?

After standing back for a few days, it is sad to see that no

new articles were posted on this, neither in BGO nor RBG.

I wonder if some of you may at times feel as I do, failing

to making an iota of difference with all that we write here?

No matter, personally I enjoy rational debate just for the

sake of it. So, let's pick up from your last post in BGO:

https://www.bgonline.org/forums/webbbs_config.pl?read=210853

Have you thought any more about whether you agree with

Kaufmann's derivation even with the said assumptions?

Your having written: "I'm mainly concerned that gammons

and the cube could change things significantly" made me

realise that I didn't know for sure if TD-Gammon v.1 was

trained playing "1-pointers", (no gammon or backgammon

wins), or "single games", (with gammon and backgammon

wins). Well, it was neither. It played "single games" with

gammons but without backgammons. Sheesh! I am sure

we will talk about the implications of this later... :(

But on the bright side, what you wrote gave me hope that

you may sooner than later accept the fact that the cube

magnifies luck without adding even a compensating, (let

alone exceeding), amount of skill to gamblegammon.

I can undestand the timid statements and the baby

steps. It's okay. Just keep walking. Come to papa... ;)

MK

Jun 21, 2023, 4:17:19 AMJun 21

to

On June 12, 2023 at 5:51:50 AM UTC-6, Axel Reichert wrote:

> .....

I'm not trying to ignore you and would like to

discuss these kinds of subjects with you but

I honestly don't understand what exactly are

you trying to prove...?

I stopped doing even my experiments setting

the error level to maximum 1.0, as a substitute

for true random play, because it really doesn't

make sense to make a bot, that I argue is biased,

play against itself regardless how much noise is

added, (especially not even knowing how exactly

it is done), because any amount of bias is bias

and it is likely to keep compounding with longer

trials.

I'm not all that familiar with the command line

functions as you may be. I suspect it would be

fairly easy to send random cube decisions but

I don't know if it is possible to query the bot for

all legal moves and picl/send a random checker

decision? If you know how to do this, why don't

you have whatever levels of the "biased bot"

play against random cube and checker play?

That would be so much more meaningful. Too

bad the Noo-BG team won't add even the most

technically trivial yet eXtremely useful features

to their cheating, err, teaching ;) bot...?

MK

> .....

> The difference between 0.05 noise and 0.1

> noise is HUGE, even "Beginner" has only.....
I'm not trying to ignore you and would like to

discuss these kinds of subjects with you but

I honestly don't understand what exactly are

you trying to prove...?

I stopped doing even my experiments setting

the error level to maximum 1.0, as a substitute

for true random play, because it really doesn't

make sense to make a bot, that I argue is biased,

play against itself regardless how much noise is

added, (especially not even knowing how exactly

it is done), because any amount of bias is bias

and it is likely to keep compounding with longer

trials.

I'm not all that familiar with the command line

functions as you may be. I suspect it would be

fairly easy to send random cube decisions but

I don't know if it is possible to query the bot for

all legal moves and picl/send a random checker

decision? If you know how to do this, why don't

you have whatever levels of the "biased bot"

play against random cube and checker play?

That would be so much more meaningful. Too

bad the Noo-BG team won't add even the most

technically trivial yet eXtremely useful features

to their cheating, err, teaching ;) bot...?

MK

Jun 21, 2023, 4:28:59 AMJun 21

to

On June 12, 2023 at 5:56:59 AM UTC-6, Axel Reichert wrote:

> MK <mu...@compuplus.net> writes:

>> On June 8, 2023 at 7:12:31 AM UTC-6, Axel Reichert wrote:

>>> ... but it increases the number of skillful

>>> decisions by at least 50 per cent,

>> Who says?

> MK <mu...@compuplus.net> writes:

>> On June 8, 2023 at 7:12:31 AM UTC-6, Axel Reichert wrote:

>>> ... but it increases the number of skillful

>>> decisions by at least 50 per cent,

>> Who says?

> Imagine the cube staying in the middle for

> the whole game. Then obviously the number

> of decisions has doubled

I was questioning your statement "skillful
> the whole game. Then obviously the number

> of decisions has doubled

decisions". Now that you dropped the word

"skillful", I will only object to the percentage.

> If the cube is turned .... then only the cube

> owner has an additional cube decision,

> which amounts to 50 per cent more decisions.

Since you corrected yourself that even the
> which amounts to 50 per cent more decisions.

non-skillful cube decisions woud increase

by less than 50%, I will leave this here well

alone, as I see no real benefit in dwelling on

it beyond this. Thanks for clarifying. Let's

discuss more exciting things...

MK

Jun 22, 2023, 5:31:56 PMJun 22

to

MK <mu...@compuplus.net> writes:

> On June 12, 2023 at 5:51:50 AM UTC-6, Axel Reichert wrote:

>

>> .....

>> The difference between 0.05 noise and 0.1

>> noise is HUGE, even "Beginner" has only.....

>

> I'm not trying to ignore you and would like to

> discuss these kinds of subjects with you but

> I honestly don't understand what exactly are

> you trying to prove...?

Imagine you are a casual player (0.05 noise for both checkers and
> On June 12, 2023 at 5:51:50 AM UTC-6, Axel Reichert wrote:

>

>> .....

>> The difference between 0.05 noise and 0.1

>> noise is HUGE, even "Beginner" has only.....

>

> I'm not trying to ignore you and would like to

> discuss these kinds of subjects with you but

> I honestly don't understand what exactly are

> you trying to prove...?

cube). If you then enhance your cube handling to expert it will

compensate roughly your checker play deteriorating from casual player to

0.1 noise (almost clueless). This is cube skill.

> I suspect it would be fairly easy to send random cube decisions but I

> don't know if it is possible to query the bot for all legal moves and

> picl/send a random checker decision?

> If you know how to do this,

> why don't you have whatever levels of the "biased bot" play against

> random cube and checker play?

prove". Define precisely what checker/cube skill I should pair against

which. Maybe I can detect a slight trace of meaning in the setup and

might do it.

Axel

Jun 23, 2023, 5:04:06 AMJun 23

to

>> why don't you have whatever levels of the

>> "biased bot" play against random cube

>> and checker play?

> Because "I honestly don't understand what

> exactly are you trying to prove".

Fair enough. I may be the one failing to make
>> "biased bot" play against random cube

>> and checker play?

> Because "I honestly don't understand what

> exactly are you trying to prove".

my point clear. I will try better.

> Define precisely what checker/cube skill I

> should pair against which. Maybe I can

> detect a slight trace of meaning in the

> setup and might do it.

from my suggestion to Tim:

"For example, you can run cubeful and

"cubeless matches between unequal

"players to see if the winning probability

"does indeed increase more slowly

"because of the cube.

to that issue. Here is what I suggest you do:

Have Noo-BG "beginner" play against "4-ply"

a large number, (1,000? 10,000?), of 1, 5, 13,

25 point matches, each first cubeless then

again cubeful.

Personally, I would go with shorter cubeless

1, 3, 7, 13 point matches but it may be even

better to do both sets of lengths.

Also, I would try fewer, (i.e. 1,000) matches of

more varied lengths first, to see if I am on the

right track; then run more, (i.e. another 9,000).

Since we don't know the ELO/ER/PR of the

"beginner" and "4-ply" beforehand, we'll do

our calculations using the resulting values.

For "4-ply", ER will be zero. For "beginner"s ER,

I think the manual says 26 to 35. Let's say 30.

For converting to ELO, I happened on this bit:

1 PR = 33 Elo (according to eXtreme Gammon)

1 ER = 26 Elo (according to Stick)

Let's say 30 as a number in the middle also.

For winning probability, we will of course use:

1-(1/(10^((ELOdiff)*SQRT(ML)/2000)+1))

After 1,000 cubeless matches, if "beginner"s

ER is 30, for example, and the ELO difference

is 30*30=900, we will calculate his probabilities

of winning for each cubeless match length and

compare to his actual winnings.

If Noo-BG's assessment of errors is accurate,

after 1,000 cubeful matches, "beginner"s ER

and ELO difference should also be 30 and 900.

Again, will calculate his probabilities of winning

for each cubeful match length and compare to

his actual winnings.

The goal is to see how does the probabilities of

winning increase as the match lengths increase,

and how the actual number of wins compare to

the predicted numbers.

If the difference is small enough to call it "hand

waving", you gamblegammon mathematicians

may be able to live with it happyly ever after. If

it is big enough to call the formula "bullshit", I

will be happily vindicated ever after.

This experiment will be useful in another way

also. By modifying the formula and applying to

our results, we can calculate "effective match

lengths" for all cubeless and cubeful declared

match lengths. For this, 1-point matches have

a special usefulness. Even if it's awkward to

call them "matches", they are so theoretically

and technically. What's unique about them is

that a cubeless 1-pointer is the same as a

cubeful 1-pointer, with the same "effective

match length".

In this aspect of the experiment, we don't know

what to expect other than my prediction that

"effective match lengths" for cufeful matches

will increase at a slower rate than for cubeless

matches.

If this comes true, then it will also vindicate my

argument that the "cube magnifies luck", rather

than skill, at an "increasing rate", as the match

length increases, (thus, reversely, it will cause

the "effective match length" to increase at a

"decreasing rate"), thus proving the so-called

"cube skill theory" a pile of "bullshit" also!

Let me know if I were able explain it all clearly

this time? And if you will do the experiment?

(Once you create the script or utility, I would

be glad to do some of the grunt work on my

computer but you may not trust the results as

much as you would if you do it all yourself).

MK

Reply all

Reply to author

Forward

0 new messages

Search

Clear search

Close search

Google apps

Main menu