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If the human brain were so simple that we could understand it, we would be so simple we couldn't.

interests / rec.games.backgammon / Rollout: Too risky to hit?

Too risky to hit?

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From: tchow12...@yahoo.com (Timothy Chow)
Newsgroups: rec.games.backgammon
Subject: Too risky to hit?
Date: Mon, 17 Oct 2022 09:21:28 -0400
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by: Timothy Chow - Mon, 17 Oct 2022 13:21 UTC

XGID=-BBAA-C-B-A-bBac---cbAbb--:1:1:1:52:0:0:0:0:10

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 X O O |
| X O | | O O O O |
| O | | O |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | X | +---+
| O X | | X X X | | 2 |
| O X X | | X X X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 104 O: 105 X-O: 0-0
Cube: 2, X own cube
X to play 52

---
Tim Chow

Rollout: Too risky to hit?

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From: tchow12...@yahoo.com (Timothy Chow)
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Subject: Rollout: Too risky to hit?
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by: Timothy Chow - Wed, 19 Oct 2022 12:57 UTC

XGID=-BBAA-C-B-A-bBac---cbAbb--:1:1:1:52:0:0:0:0:10

If you have browsed the old posts from Stick's forum that I recently
copied to my website, this problem may remind you of "Do you have the
guts to hit?"

http://alum.mit.edu/www/tchow/cg/www.bgonline.org/forums/160751.html

There, whether or not the computer hits depends on the cube location.
Here, XG does not hit, regardless of the cube location. Hitting is
its DMP play but O's four-point board means that X loses a ton of
gammons if he hits.

1. Rollout¹ 8/3 6/4 eq:-0.292
Player: 32.80% (G:6.79% B:0.08%)
Opponent: 67.20% (G:10.33% B:0.14%)
Confidence: ±0.005 (-0.297..-0.287) - [100.0%]

2. Rollout¹ 21/14* eq:-0.363 (-0.071)
Player: 38.13% (G:10.00% B:0.17%)
Opponent: 61.87% (G:36.57% B:3.15%)
Confidence: ±0.007 (-0.370..-0.356) - [0.0%]

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

eXtreme Gammon Version: 2.19.211.pre-release

---
Tim Chow

Subject	Author
Too risky to hit?	Timothy Chow
Rollout: Too risky to hit?	Timothy Chow