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interests / rec.games.backgammon / Re: Well hit-dance would be a great sequence so why don't you think I have an action double?

SubjectAuthor
* Well hit-dance would be a great sequence so why don't you think Ipeps...@gmail.com
+* Re: Well hit-dance would be a great sequence so why don't you think Ipeps...@gmail.com
|`- Re: Well hit-dance would be a great sequence so why don't you think I have an acpeps...@gmail.com
+- Re: Well hit-dance would be a great sequence so why don't you think ITimothy Chow
`* Re: Well hit-dance would be a great sequence so why don't you think Iah...Clem
 `* Re: Well hit-dance would be a great sequence so why don't you think Ipeps...@gmail.com
  `* Re: Well hit-dance would be a great sequence so why don't you think ITimothy Chow
   `- Re: Well hit-dance would be a great sequence so why don't you think I have an acpeps...@gmail.com

1
Well hit-dance would be a great sequence so why don't you think I have an action double?

<ca919276-e452-45cc-bbd8-051bfc2d6302n@googlegroups.com>

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Subject: Well hit-dance would be a great sequence so why don't you think I
have an action double?
From: pepste...@gmail.com (peps...@gmail.com)
Injection-Date: Sun, 23 May 2021 11:21:47 +0000
Content-Type: text/plain; charset="UTF-8"
 by: peps...@gmail.com - Sun, 23 May 2021 11:21 UTC

XGID=--ADaBD-C-a---a--ccc-ab--A:0:0:1:00:0:0:3:0:10
X:Daniel O:eXtremeGammon

Score is X:0 O:0. Unlimited Game, Jacoby Beaver
+13-14-15-16-17-18------19-20-21-22-23-24-+
| O O O | | O O O |
| O O | | O O |
| O O | | O |
| | | |
| | X | |
| |BAR| |
| | | |
| | | X X |
| X | | X X |
| X | | X X X |
| O X | | X X O X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 97 O: 120 X-O: 0-0
Cube: 1
X on roll, cube action

Re: Well hit-dance would be a great sequence so why don't you think I have an action double?

<5612251b-28d0-455a-b5ed-107aa2977424n@googlegroups.com>

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Subject: Re: Well hit-dance would be a great sequence so why don't you think I
have an action double?
From: pepste...@gmail.com (peps...@gmail.com)
Injection-Date: Sun, 23 May 2021 11:24:58 +0000
Content-Type: text/plain; charset="UTF-8"
 by: peps...@gmail.com - Sun, 23 May 2021 11:24 UTC

On Sunday, May 23, 2021 at 12:21:47 PM UTC+1, peps...@gmail.com wrote:
> XGID=--ADaBD-C-a---a--ccc-ab--A:0:0:1:00:0:0:3:0:10
> X:Daniel O:eXtremeGammon
>
> Score is X:0 O:0. Unlimited Game, Jacoby Beaver
> +13-14-15-16-17-18------19-20-21-22-23-24-+
> | O O O | | O O O |
> | O O | | O O |
> | O O | | O |
> | | | |
> | | X | |
> | |BAR| |
> | | | |
> | | | X X |
> | X | | X X |
> | X | | X X X |
> | O X | | X X O X X |
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 97 O: 120 X-O: 0-0
> Cube: 1
> X on roll, cube action
Is my title too long BTW?
I have been trying to make them acceptably short.
I'm not sure whether this effort crosses length boundaries or not?

Thanks,

Paul

Re: Well hit-dance would be a great sequence so why don't you think I have an action double?

<d011a07a-9f21-40c6-9e6b-afd789a46fb0n@googlegroups.com>

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Subject: Re: Well hit-dance would be a great sequence so why don't you think I have an action double?
From: pepste...@gmail.com (peps...@gmail.com)
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 by: peps...@gmail.com - Sun, 23 May 2021 11:31 UTC

On Sunday, May 23, 2021 at 12:24:58 PM UTC+1, peps...@gmail.com wrote:
> On Sunday, May 23, 2021 at 12:21:47 PM UTC+1, peps...@gmail.com wrote:
> > XGID=--ADaBD-C-a---a--ccc-ab--A:0:0:1:00:0:0:3:0:10
> > X:Daniel O:eXtremeGammon
> >
> > Score is X:0 O:0. Unlimited Game, Jacoby Beaver
> > +13-14-15-16-17-18------19-20-21-22-23-24-+
> > | O O O | | O O O |
> > | O O | | O O |
> > | O O | | O |
> > | | | |
> > | | X | |
> > | |BAR| |
> > | | | |
> > | | | X X |
> > | X | | X X |
> > | X | | X X X |
> > | O X | | X X O X X |
> > +12-11-10--9--8--7-------6--5--4--3--2--1-+
> > Pip count X: 97 O: 120 X-O: 0-0
> > Cube: 1
> > X on roll, cube action
> Is my title too long BTW?
> I have been trying to make them acceptably short.
> I'm not sure whether this effort crosses length boundaries or not?
>
> Thanks,
>
> Paul
Yes, at 88 chars, it's too long because they shouldn't be > 72.
Sorry.

Paul

Re: Well hit-dance would be a great sequence so why don't you think I have an action double?

<s8f3mo$g07$1@dont-email.me>

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From: tchow12...@yahoo.com (Timothy Chow)
Newsgroups: rec.games.backgammon
Subject: Re: Well hit-dance would be a great sequence so why don't you think I
have an action double?
Date: Sun, 23 May 2021 22:40:22 -0400
Organization: A noiseless patient Spider
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 by: Timothy Chow - Mon, 24 May 2021 02:40 UTC

On 5/23/2021 7:21 AM, peps...@gmail.com wrote:
> XGID=--ADaBD-C-a---a--ccc-ab--A:0:0:1:00:0:0:3:0:10
> X:Daniel O:eXtremeGammon
>
> Score is X:0 O:0. Unlimited Game, Jacoby Beaver
> +13-14-15-16-17-18------19-20-21-22-23-24-+
> | O O O | | O O O |
> | O O | | O O |
> | O O | | O |
> | | | |
> | | X | |
> | |BAR| |
> | | | |
> | | | X X |
> | X | | X X |
> | X | | X X X |
> | O X | | X X O X X |
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 97 O: 120 X-O: 0-0
> Cube: 1
> X on roll, cube action

X is 23 pips up with a stronger board, but he is on the bar, and he
has a blot in his board, and O has only one checker back. That looks
like a clear take to me. This is not the sort of position I usually
double because there aren't that many market losers. Even if X hits,
it might not be a market loser. ND/T for me, although I do have a
tendency to miss this type of double.

---
Tim Chow

Re: Well hit-dance would be a great sequence so why don't you think I have an action double?

<s8h9om$n15$2@dont-email.me>

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From: ah_c...@ymail.com (ah...Clem)
Newsgroups: rec.games.backgammon
Subject: Re: Well hit-dance would be a great sequence so why don't you think I
have an action double?
Date: Mon, 24 May 2021 18:36:03 -0400
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 by: ah...Clem - Mon, 24 May 2021 22:36 UTC

On 5/23/2021 7:21 AM, peps...@gmail.com wrote:
> XGID=--ADaBD-C-a---a--ccc-ab--A:0:0:1:00:0:0:3:0:10
> X:Daniel O:eXtremeGammon
>
> Score is X:0 O:0. Unlimited Game, Jacoby Beaver
> +13-14-15-16-17-18------19-20-21-22-23-24-+
> | O O O | | O O O |
> | O O | | O O |
> | O O | | O |
> | | | |
> | | X | |
> | |BAR| |
> | | | |
> | | | X X |
> | X | | X X |
> | X | | X X X |
> | O X | | X X O X X |
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 97 O: 120 X-O: 0-0
> Cube: 1
> X on roll, cube action
>

The take seems pretty clear with the race lead, X on the roof, and no
outfield control on X's part. While there are abundant market losers,
there are also a bunch of bad sequences for X that will boomerang the cube.

ND/T.

Re: Well hit-dance would be a great sequence so why don't you think I have an action double?

<3f08d0f6-c021-4cf6-87cc-07d8d4936258n@googlegroups.com>

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Subject: Re: Well hit-dance would be a great sequence so why don't you think I
have an action double?
From: pepste...@gmail.com (peps...@gmail.com)
Injection-Date: Tue, 25 May 2021 07:19:11 +0000
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 by: peps...@gmail.com - Tue, 25 May 2021 07:19 UTC

On Monday, May 24, 2021 at 11:36:08 PM UTC+1, ah...Clem wrote:
> On 5/23/2021 7:21 AM, peps...@gmail.com wrote:
> > XGID=--ADaBD-C-a---a--ccc-ab--A:0:0:1:00:0:0:3:0:10
> > X:Daniel O:eXtremeGammon
> >
> > Score is X:0 O:0. Unlimited Game, Jacoby Beaver
> > +13-14-15-16-17-18------19-20-21-22-23-24-+
> > | O O O | | O O O |
> > | O O | | O O |
> > | O O | | O |
> > | | | |
> > | | X | |
> > | |BAR| |
> > | | | |
> > | | | X X |
> > | X | | X X |
> > | X | | X X X |
> > | O X | | X X O X X |
> > +12-11-10--9--8--7-------6--5--4--3--2--1-+
> > Pip count X: 97 O: 120 X-O: 0-0
> > Cube: 1
> > X on roll, cube action
> >
> The take seems pretty clear with the race lead, X on the roof, and no
> outfield control on X's part. While there are abundant market losers,
> there are also a bunch of bad sequences for X that will boomerang the cube.
>
> ND/T.

I was very surprised to get penalised for a missed double here.
The non-doubling equity is only 0.2, the position is volatile,
so why double?
I think this might be a classic Jacoby double.
There's a huge (20%) gammon discrepancy so we double
to make the gammons count.
I think that variantizing non-Jacobishly would result in a clear hold.

Paul

Analyzed in Rollout
No double
Player Winning Chances: 54.11% (G:26.50% B:1.31%)
Opponent Winning Chances: 45.89% (G:6.89% B:0.29%)
Double/Take
Player Winning Chances: 54.55% (G:27.25% B:1.56%)
Opponent Winning Chances: 45.45% (G:7.20% B:0.31%)

Cubeless Equities: No Double=+0.289, Double=+0.608

Cubeful Equities:
No double: +0.181 (-0.078)
Double/Take: +0.259
Double/Pass: +1.000 (+0.741)

Best Cube action: Double / Take

Rollout:
1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.011 (+0.170..+0.192)
Confidence Double: ± 0.015 (+0.244..+0.274)

Double Decision confidence: 100.0%
Take Decision confidence: 100.0%

Duration: 35 minutes 33 seconds

eXtreme Gammon Version: 2.10

Re: Well hit-dance would be a great sequence so why don't you think I have an action double?

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From: tchow12...@yahoo.com (Timothy Chow)
Newsgroups: rec.games.backgammon
Subject: Re: Well hit-dance would be a great sequence so why don't you think I
have an action double?
Date: Tue, 25 May 2021 09:38:39 -0400
Organization: A noiseless patient Spider
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 by: Timothy Chow - Tue, 25 May 2021 13:38 UTC

On 5/25/2021 3:19 AM, peps...@gmail.com wrote:
> The non-doubling equity is only 0.2, the position is volatile,
> so why double?

Volatility is usually an argument *for* doubling, not *against*.

> I think this might be a classic Jacoby double.
> There's a huge (20%) gammon discrepancy so we double
> to make the gammons count.
> I think that variantizing non-Jacobishly would result in a clear hold.

Good thought, although I prefer to say that there are exchanges that
make X too good (44 or 22 followed by a dance is the most obvious,
but I suspect there are others). The rollout below says that if we
remove the Jacoby rule then it's on the D/ND borderline.

XGID=--ADaBD-C-a---a--ccc-ab--A:0:0:1:00:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| O O O | | O O O |
| O O | | O O |
| O O | | O |
| | | |
| | X | |
| |BAR| |
| | | |
| | | X X |
| X | | X X |
| X | | X X X |
| O X | | X X O X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 97 O: 120 X-O: 0-0
Cube: 1
X on roll, cube action

Analyzed in Rollout
No double
Player Winning Chances: 54.24% (G:27.10% B:1.68%)
Opponent Winning Chances: 45.76% (G:7.16% B:0.30%)
Double/Take
Player Winning Chances: 54.43% (G:27.18% B:1.56%)
Opponent Winning Chances: 45.57% (G:7.17% B:0.30%)

Cubeful Equities:
No double: +0.256
Double/Take: +0.247 (-0.010)
Double/Pass: +1.000 (+0.744)

Best Cube action: No double / Take
Percentage of wrong pass needed to make the double decision right: 1.3%

Rollout:
2592 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.008 (+0.249..+0.264)
Confidence Double: ± 0.012 (+0.235..+0.258)

eXtreme Gammon Version: 2.19.207.pre-release

---
Tim Chow

Re: Well hit-dance would be a great sequence so why don't you think I have an action double?

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Date: Wed, 26 May 2021 10:12:00 -0700 (PDT)
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Subject: Re: Well hit-dance would be a great sequence so why don't you think I have an action double?
From: pepste...@gmail.com (peps...@gmail.com)
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 by: peps...@gmail.com - Wed, 26 May 2021 17:12 UTC

On Tuesday, May 25, 2021 at 2:38:43 PM UTC+1, Tim Chow wrote:
> On 5/25/2021 3:19 AM, peps...@gmail.com wrote:
> > The non-doubling equity is only 0.2, the position is volatile,
> > so why double?
> Volatility is usually an argument *for* doubling, not *against*.
> > I think this might be a classic Jacoby double.
> > There's a huge (20%) gammon discrepancy so we double
> > to make the gammons count.
> > I think that variantizing non-Jacobishly would result in a clear hold.
> Good thought, although I prefer to say that there are exchanges that
> make X too good (44 or 22 followed by a dance is the most obvious,
> but I suspect there are others). The rollout below says that if we
> remove the Jacoby rule then it's on the D/ND borderline.
>
> XGID=--ADaBD-C-a---a--ccc-ab--A:0:0:1:00:0:0:0:0:10
>
> X:Player 1 O:Player 2
> Score is X:0 O:0. Unlimited Game
> +13-14-15-16-17-18------19-20-21-22-23-24-+
> | O O O | | O O O |
> | O O | | O O |
> | O O | | O |
> | | | |
> | | X | |
> | |BAR| |
> | | | |
> | | | X X |
> | X | | X X |
> | X | | X X X |
> | O X | | X X O X X |
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 97 O: 120 X-O: 0-0
> Cube: 1
> X on roll, cube action
> Analyzed in Rollout
> No double
> Player Winning Chances: 54.24% (G:27.10% B:1.68%)
> Opponent Winning Chances: 45.76% (G:7.16% B:0.30%)
> Double/Take
> Player Winning Chances: 54.43% (G:27.18% B:1.56%)
> Opponent Winning Chances: 45.57% (G:7.17% B:0.30%)
>
> Cubeful Equities:
> No double: +0.256
> Double/Take: +0.247 (-0.010)
> Double/Pass: +1.000 (+0.744)
>
> Best Cube action: No double / Take
> Percentage of wrong pass needed to make the double decision right: 1.3%
>
> Rollout:
> 2592 Games rolled with Variance Reduction.
> Dice Seed: 271828
> Moves: 3-ply, cube decisions: XG Roller
> Confidence No Double: ± 0.008 (+0.249..+0.264)
> Confidence Double: ± 0.012 (+0.235..+0.258)
>
> eXtreme Gammon Version: 2.19.207.pre-release

Thanks for your sterling variantizing.
It's evidence for a point you made that cube actions are rarely affected by Jacoby.
This position would seem tailor-made for considering Jacoby.
The advantage is minimal for a doubling position, and the main strength is the gammons edge.
The gammons gap is more than twice the wins gap.
But even in this example, playing the positions the same way (by doubling in both) is at worst
a miniscule error.

Paul

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