Message-ID:

6 May, 2024: The networking issue during the past two days has been identified and fixed.

interests / rec.games.backgammon / Rollout: Best way to contain?

Best way to contain?

<tim6kj$3ns0i$3@dont-email.me>

https://www.novabbs.com/interests/article-flat.php?id=10184&group=rec.games.backgammon#10184

copy link Newsgroups: rec.games.backgammon

Path: i2pn2.org!i2pn.org!eternal-september.org!reader01.eternal-september.org!.POSTED!not-for-mail
From: tchow12...@yahoo.com (Timothy Chow)
Newsgroups: rec.games.backgammon
Subject: Best way to contain?
Date: Tue, 18 Oct 2022 08:36:35 -0400
Organization: A noiseless patient Spider
Lines: 23
Message-ID: <tim6kj$3ns0i$3@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Tue, 18 Oct 2022 12:36:35 -0000 (UTC)
Injection-Info: reader01.eternal-september.org; posting-host="4760cf25d118467e9831a6de233cc8b9";
logging-data="3928082"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX197yZIcZc7vbZHzfdEI3fYp+fFWHNkmR7I="
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
Thunderbird/102.3.3
Cancel-Lock: sha1:rlfyaD+7mnx/ZdXtAbM/DYXG41A=
Content-Language: en-US

by: Timothy Chow - Tue, 18 Oct 2022 12:36 UTC

XGID=--BCaDB--bB-----B--babbcb-:1:1:1:64:0:0:0:0:10

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-+
| X | | O O O O O O |
| X | | O O O O O |
| | | O |
| | | |
| | | |
| |BAR| |
| | | |
| | | X |
| | | X X | +---+
| X O | | X X X X | | 2 |
| X O | | X X O X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 97 O: 92 X-O: 0-0
Cube: 2, X own cube
X to play 64

---
Tim Chow

Rollout: Best way to contain?

<tiri78$baqu$1@dont-email.me>

copy mid

https://www.novabbs.com/interests/article-flat.php?id=10196&group=rec.games.backgammon#10196

copy link Newsgroups: rec.games.backgammon

Path: i2pn2.org!i2pn.org!eternal-september.org!reader01.eternal-september.org!.POSTED!not-for-mail
From: tchow12...@yahoo.com (Timothy Chow)
Newsgroups: rec.games.backgammon
Subject: Rollout: Best way to contain?
Date: Thu, 20 Oct 2022 09:24:56 -0400
Organization: A noiseless patient Spider
Lines: 139
Message-ID: <tiri78$baqu$1@dont-email.me>
References: <tim6kj$3ns0i$3@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Thu, 20 Oct 2022 13:24:56 -0000 (UTC)
Injection-Info: reader01.eternal-september.org; posting-host="1aa95de0834549140f4d613b1326d570";
logging-data="371550"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19EnrNR1jJ42yw4hfyNlJ3+m6lQcV4DGv0="
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
Thunderbird/102.3.3
Cancel-Lock: sha1:QLHylbfH52w1pqBRKI7e471HJUk=
In-Reply-To: <tim6kj$3ns0i$3@dont-email.me>
Content-Language: en-US

by: Timothy Chow - Thu, 20 Oct 2022 13:24 UTC

XGID=--BCaDB--bB-----B--babbcb-:1:1:1:64:0:0:0:0:10

Doug Zare once wrote a GammonVillage article on "Late Loose Hits."
You can often get a surprisingly accurate estimate of the game-winning
chances of the loose hit by pretending that you lose if the opponent
hits back and you win otherwise. In this position, that crude heuristic
would suggest that you win 64% of the time, which is pretty close to
what XG says. Of course, there are also gammons to consider, and the
state of the opponent's board matters for that. According to the
rollouts below, you should definitely hit in this position, but if O's
dead checker on her 2pt were on her 6pt, XG plays safe with 16/6.

For good measure, I've also included the rollout of the decision I faced
on the next turn.

1. Rollout¹ 10/6 10/4* eq:+0.504
Player: 62.14% (G:19.31% B:0.52%)
Opponent: 37.86% (G:7.90% B:0.10%)
Confidence: ±0.004 (+0.500..+0.509) - [100.0%]

2. Rollout¹ 16/6 eq:+0.410 (-0.094)
Player: 57.96% (G:7.49% B:0.40%)
Opponent: 42.04% (G:2.90% B:0.04%)
Confidence: ±0.007 (+0.404..+0.417) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.207.pre-release

-------
Variant
-------

XGID=--BCaDB--bB-----B--cabbbb-:1:1:1:64:0:0:0:0:10

1. Rollout¹ 16/6 eq:+0.429
Player: 58.83% (G:6.68% B:0.32%)
Opponent: 41.17% (G:3.38% B:0.05%)
Confidence: ±0.006 (+0.423..+0.435) - [100.0%]

2. Rollout¹ 10/6 10/4* eq:+0.386 (-0.043)
Player: 57.65% (G:17.56% B:0.45%)
Opponent: 42.35% (G:12.22% B:0.12%)
Confidence: ±0.005 (+0.381..+0.391) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.207.pre-release

---------
Next turn
---------

XGID=--BCaDC--aB-----Aa-babbcb-:1:-1:1:65:0:0:0:0:10

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-+
| X O | | O O O O O O | +---+
| | | O O O O O | | 2 |
| | | O | +---+
| | | |
| | | |
| |BAR| |
| | | |
| | | X |
| | | X X X |
| X | | X X X X |
| X O | | X X O X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 87 O: 84 X-O: 0-0
Cube: 2, O own cube
X to play 65

1. Rollout¹ 16/5 eq:+0.274
Player: 68.29% (G:1.42% B:0.03%)
Opponent: 31.71% (G:0.81% B:0.02%)
Confidence: ±0.004 (+0.269..+0.278) - [100.0%]

2. Rollout¹ 16/10 6/1 eq:+0.226 (-0.048)
Player: 65.92% (G:1.85% B:0.04%)
Opponent: 34.08% (G:1.10% B:0.01%)
Confidence: ±0.004 (+0.221..+0.230) - [0.0%]

3. Rollout¹ 10/5 10/4* eq:+0.169 (-0.104)
Player: 60.36% (G:12.57% B:0.44%)
Opponent: 39.64% (G:9.70% B:0.22%)
Confidence: ±0.005 (+0.165..+0.174) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.207.pre-release

---
Tim Chow

Subject	Author
Best way to contain?	Timothy Chow
Rollout: Best way to contain?	Timothy Chow