Re: Interesting question/experiment about value of cube ownership

[Bug reports for and general discussion about GNU Backgammon.]

"Is making the bot auto-play the
same as doing rollouts?"

It sounds like you are asking what a rollout is?  There are plenty of resources 
on the net.
https://www.gnu.org/software/gnubg/manual/html_node/Introduction-to-rollouts.html

https://www.bkgm.com/openings/rollouts.html

Your auto-play script sounds very similar but I don't know exactly what it does.

The main difference would be that you can make your scripts double using your 
own algorithm. Or indeed, veer from the bot's best chequer play.

Minor differences might be the play settings for search depth and pruning.

Try this manual sequence, and evaluate the next move. This gets you back to the 
start position. But doubles would be allowed, so the bot evaluation should not 
be the same as that of the opening roll.

64: 13/7 24/20

33: 24/18* 13/7

21: bar/24 20/18*

51: bar/24 18/13

32: 18/13




From: MK 
Sent: Friday, March 1, 2024 10:46:29 PM
To: Ian Shaw ; bug-gnubg@gnu.org 
Cc: Philippe Michel 
Subject: Re: Interesting question/experiment about value of cube ownership

On 3/1/2024 6:22 AM, Ian Shaw wrote:

> 27000 trials at 0-ply and 1-ply. 135000 trials at 2-ply.
> There’s almost no difference in value between the rollout
> that took 8 minutes and the one that tool 23 hours, which
> speaks to the strength of the initial evaluation.

This is good to know. Can you post the position ID so that
there is no misassumptions.

> The rollout suggests that the value of cube ownership in
> the initial position is worth about 0.36 points.

This is very interesting. Is making the bot auto-play the
same as doing rollouts? During the past weeks, I have done
12 different experiments with 20,000 games in each. I'm now
putting it all on a neatly organized web page which I will
share here soon.

Six of my experiments were about the value of winning the
opening roll and/or owning the cube from the start (i.e.
before the first move for the mutant but before the second
move for the bot since it always auto-plays and there is no
way to intercept before its first move).

Very interestingly I also came up with 0.36 ppg and 0.28 ppc
("points per cube" decision).

I collected and tabulated quite a lot of various stats which
will be on my web page, along with the actual scripts I ran,
saved games, log files, etc. so that you all can derive your
own conclusions with or without replicating my experiments,
with the important ones being about "mutant cube strategies".

> One thing to notice is that the rollout has the on-roll
> player winning about 1% less than the evaluations posted
> by MK. I think this is due to the evaluation assuming that
> initial doubles may be played, whereas I set the rollout
> to play as the initial position.

I'm not sure what you are referring to here. What I had posted
was the GnuBG's 2-ply evaluation of the opening position (i.e.
without initial doubles). So, that 1% must be the difference
between that and your rollouts?? (as well as my experiments?)

> I haven’t found a way toa ask gnubg for an evaluation for the
> initial roll. Is there one?
> You could get a 1-ply evaluation by combining all 15 0-ply
> evaluations of the first roll, and so forth.

I don't understand these. Hopefully others will pitch in their
comments in response...

MK


> *From:*bug-gnubg-bounces+ian.shaw=riverauto.co...@gnu.org
>  *On Behalf Of *Ian Shaw 
> via Bug reports for and
> general discussion about GNU Backgammon.
> *Sent:* Thursday, February 8, 2024 11:39 AM
> *To:* playbg-...@yahoo.com; bug-gnubg@gnu.org
> *Cc:* Philippe Michel 
> *Subject:* RE: Interesting question/experiment about value of cube ownership
>
> It just so happens that I rolled out the opening position a few days ago for 
> another reason. This
> was at 7-away 7-away rather than $ play, because I was interested in match 
> play. I doubt that makes
> a huge difference.
>
> This was using gnubg-1_08_dev-20240103-setup.exe not the newest 
> gnubg-1_08_001-20240204-setup.exe
> that Philippe released recently.
>
> Philippe, am I correct in thinking that the cube handling on these two 
> versions is the same? Your
> announcement emails both include the same comment.
>
> “Improvement to cube decisions at 0- and 1-ply and weaker levels. Cube error 
> rates are approximately
> halved and the repartition of errors (premature doubles vs. missed doubles 
> vs. take or pass errors)
> is now similar to higher plies instead of being mostly premature doubles.”
>
> The rollout results indicate about 1% fewer wins for the roller than the 
> evaluations.
>
> 4HPwATDgc/ABMA:cAngAAAE
>
> Cube analysis
>
> Rollout cubeless equity +0.0408 (Money: +0.0396)
>
> Cubeful equities:
>
> 1. No double   +0.0655
>
> 2. Double, pass+1.  (+0.9345)
>
> 3. Double, take-0.2999  (-0.3654)
>
> Proper cube action: No double, take (28.1%)
>
> Rollout details:
>
> Centered 1-cube:
>
>0.5129 0.1480 0.0083 - 0.4871 0.1351 0.0073 CL +0.0408 CF +0.0655
>
> [0.0001 0.0002

Re: Interesting question/experiment about value of cube ownership

[MK]

On 3/1/2024 6:22 AM, Ian Shaw wrote:


27000 trials at 0-ply and 1-ply. 135000 trials at 2-ply.
There’s almost no difference in value between the rollout
that took 8 minutes and the one that tool 23 hours, which
speaks to the strength of the initial evaluation.


This is good to know. Can you post the position ID so that
there is no misassumptions.


The rollout suggests that the value of cube ownership in
the initial position is worth about 0.36 points.


This is very interesting. Is making the bot auto-play the
same as doing rollouts? During the past weeks, I have done
12 different experiments with 20,000 games in each. I'm now
putting it all on a neatly organized web page which I will
share here soon.

Six of my experiments were about the value of winning the
opening roll and/or owning the cube from the start (i.e.
before the first move for the mutant but before the second
move for the bot since it always auto-plays and there is no
way to intercept before its first move).

Very interestingly I also came up with 0.36 ppg and 0.28 ppc
("points per cube" decision).

I collected and tabulated quite a lot of various stats which
will be on my web page, along with the actual scripts I ran,
saved games, log files, etc. so that you all can derive your
own conclusions with or without replicating my experiments,
with the important ones being about "mutant cube strategies".


One thing to notice is that the rollout has the on-roll
player winning about 1% less than the evaluations posted
by MK. I think this is due to the evaluation assuming that
initial doubles may be played, whereas I set the rollout
to play as the initial position.


I'm not sure what you are referring to here. What I had posted
was the GnuBG's 2-ply evaluation of the opening position (i.e.
without initial doubles). So, that 1% must be the difference
between that and your rollouts?? (as well as my experiments?)


I haven’t found a way toa ask gnubg for an evaluation for the
initial roll. Is there one?
You could get a 1-ply evaluation by combining all 15 0-ply
evaluations of the first roll, and so forth.


I don't understand these. Hopefully others will pitch in their
comments in response...

MK


*From:*bug-gnubg-bounces+ian.shaw=riverauto.co...@gnu.org 
 *On Behalf Of *Ian Shaw via Bug reports for and 
general discussion about GNU Backgammon.

*Sent:* Thursday, February 8, 2024 11:39 AM
*To:* playbg-...@yahoo.com; bug-gnubg@gnu.org
*Cc:* Philippe Michel 
*Subject:* RE: Interesting question/experiment about value of cube ownership

It just so happens that I rolled out the opening position a few days ago for another reason. This 
was at 7-away 7-away rather than $ play, because I was interested in match play. I doubt that makes 
a huge difference.


This was using gnubg-1_08_dev-20240103-setup.exe not the newest gnubg-1_08_001-20240204-setup.exe 
that Philippe released recently.


Philippe, am I correct in thinking that the cube handling on these two versions is the same? Your 
announcement emails both include the same comment.


“Improvement to cube decisions at 0- and 1-ply and weaker levels. Cube error rates are approximately 
halved and the repartition of errors (premature doubles vs. missed doubles vs. take or pass errors) 
is now similar to higher plies instead of being mostly premature doubles.”


The rollout results indicate about 1% fewer wins for the roller than the 
evaluations.

4HPwATDgc/ABMA:cAngAAAE

Cube analysis

Rollout cubeless equity +0.0408 (Money: +0.0396)

Cubeful equities:

1. No double   +0.0655

2. Double, pass    +1.  (+0.9345)

3. Double, take    -0.2999  (-0.3654)

Proper cube action: No double, take (28.1%)

Rollout details:

Centered 1-cube:

   0.5129 0.1480 0.0083 - 0.4871 0.1351 0.0073 CL +0.0408 CF +0.0655

[0.0001 0.0002 0.0001 - 0.0001 0.0001 0.0001 CL  0.0003 CF  0.0008]

gnubg owns 2-cube:

   0.5156 0.1522 0.0091 - 0.4844 0.1375 0.0150 CL +0.1216 CF -0.2999

[0.0001 0.0002 0.0001 - 0.0001 0.0002 0.0002 CL  0.0007 CF  0.0012]

Full cubeful rollout with variance reduction

186624 games, rollout as initial position, Mersenne Twister dice generator with 
seed 823069761

Play: world class 2-ply cubeful prune [world class]

keep the first 0 0-ply moves and up to 8 more moves within equity 0.16

Skip pruning for 1-ply moves.

Cube: 2-ply cubeful prune [world class]

Cheers,

Ian

-Original Message-
From: bug-gnubg-bounces+ian.shaw=riverauto.co...@gnu.org 
mailto:bug-gnubg-bounces+ian.shaw=riverauto.co...@gnu.org>> On Behalf Of MK

Sent: Thursday, February 8, 2024 2:23 AM
To: bug-gnubg@gnu.org 
Subject: Interesting question/experiment about value of cube ownership

I'm chugging along with my mutant cube skill experiments as I can spare time, saving all games, 
which I will share on my web site, when I'm done, along with my scripts.


While doing the double at > 50% experiment, I remembered an old ques

RE: Interesting question/experiment about value of cube ownership

[Bug reports for and general discussion about GNU Backgammon.]

I've rolled at the opening position again, at money play.
27000 trials at 0-ply and 1-ply. 135000 trials at 2-ply.  There's almost no 
difference in value between the rollout that took 8 minutes and the one that 
tool 23 hours, which speaks to the strength of the initial evaluation.

The rollout suggests that the value of cube ownership in the initial position 
is worth about 0.36 points.

One thing to notice is that the rollout has the on-roll player winning about 1% 
less than the evaluations posted by MK. I think this is due to the evaluation 
assuming that initial doubles may be played, whereas I set the rollout to play 
as the initial position.

Ply

Cube

Pwin

Pwin2

Pwin3

Plose

Plose2

Plose3

Ecl

End

Edt

Action

0

1Cen

0.5135

0.1425

0.0065

0.4865

0.1310

0.0055

+0.0395

+0.0599





8 m

2Opp

0.5141

0.1428

0.0064

0.4859

0.1317

0.0056

+0.0804



-0.2941

NB (27.4%)

1

1Cen

0.5136

0.1472

0.0071

0.4864

0.1352

0.0059

+0.0405

+0.0594





38 m

2Opp

0.5136

0.1495

0.0074

0.4864

0.1350

0.0060

+0.0867



-0.2977

NB (27.5%)

2

1Cen

0.5130

0.1461

0.0069

0.4870

0.1336

0.0058

+0.0395

+0.0580





23 h

2Opp

0.5147

0.1468

0.0068

0.4853

0.1332

0.0059

+0.0881



-0.3002

NB (27.6%)



I haven't found a way toa ask gnubg for an evaluation for the initial roll. Is 
there one?
You could get a 1-ply evaluation by combining all 15 0-ply evaluations of the 
first roll, and so forth.

Cheers,
Ian



From: bug-gnubg-bounces+ian.shaw=riverauto.co...@gnu.org 
 On Behalf Of Ian Shaw via 
Bug reports for and general discussion about GNU Backgammon.
Sent: Thursday, February 8, 2024 11:39 AM
To: playbg-...@yahoo.com; bug-gnubg@gnu.org
Cc: Philippe Michel 
Subject: RE: Interesting question/experiment about value of cube ownership




It just so happens that I rolled out the opening position a few days ago for 
another reason. This was at 7-away 7-away rather than $ play, because I was 
interested in match play. I doubt that makes a huge difference.



This was using gnubg-1_08_dev-20240103-setup.exe not the newest 
gnubg-1_08_001-20240204-setup.exe that Philippe released recently.



Philippe, am I correct in thinking that the cube handling on these two versions 
is the same? Your announcement emails both include the same comment.

"Improvement to cube decisions at 0- and 1-ply and weaker levels. Cube error 
rates are approximately halved and the repartition of errors (premature doubles 
vs. missed doubles vs. take or pass errors) is now similar to higher plies 
instead of being mostly premature doubles."



The rollout results indicate about 1% fewer wins for the roller than the 
evaluations.



4HPwATDgc/ABMA:cAngAAAE



Cube analysis

Rollout cubeless equity +0.0408 (Money: +0.0396)



Cubeful equities:

1. No double   +0.0655

2. Double, pass+1.  (+0.9345)

3. Double, take-0.2999  (-0.3654)

Proper cube action: No double, take (28.1%)



Rollout details:

Centered 1-cube:

  0.5129 0.1480 0.0083 - 0.4871 0.1351 0.0073 CL +0.0408 CF +0.0655

[0.0001 0.0002 0.0001 - 0.0001 0.0001 0.0001 CL  0.0003 CF  0.0008]

gnubg owns 2-cube:

  0.5156 0.1522 0.0091 - 0.4844 0.1375 0.0150 CL +0.1216 CF -0.2999

[0.0001 0.0002 0.0001 - 0.0001 0.0002 0.0002 CL  0.0007 CF  0.0012]

Full cubeful rollout with variance reduction

186624 games, rollout as initial position, Mersenne Twister dice generator with 
seed 823069761

Play: world class 2-ply cubeful prune [world class]

keep the first 0 0-ply moves and up to 8 more moves within equity 0.16

Skip pruning for 1-ply moves.

Cube: 2-ply cubeful prune [world class]



Cheers,

Ian



-Original Message-
From: 
bug-gnubg-bounces+ian.shaw=riverauto.co...@gnu.org
 
mailto:bug-gnubg-bounces+ian.shaw=riverauto.co...@gnu.org>>
 On Behalf Of MK
Sent: Thursday, February 8, 2024 2:23 AM
To: bug-gnubg@gnu.org
Subject: Interesting question/experiment about value of cube ownership



I'm chugging along with my mutant cube skill experiments as I can spare time, 
saving all games, which I will share on my web site, when I'm done, along with 
my scripts.



While doing the double at > 50% experiment, I remembered an old question I had 
asked in RGB about a year ago: What if the winner of the opening roll is 
allowed pre-double?



See thread:

https://groups.google.com/g/rec.games.backgammon/c/BVEnaqGM6dg/m/2c685q4DAAAJ



When you evaluate the opening position in GnuBG, this is what you get:



=

Position ID: 4HPwATDgc/ABMA

Match ID:cAkA



Evaluator:Contact

 Win W(g)W(bg)   L(g)L(bg)   EquityCubeful

static:  52.115.4 0.813.0 0.8   +0.067+0.084

  1 ply:  52.714.8 0.912.9 0.5   +0.076+0.098

  2 ply:  52.514.9 0.712.5 0.5   +0.076+0.099



Cube analysi