On Saturday, August 14, 2021 at 8:47:26 PM UTC-4, Tim Chow wrote:
XGID=-BAbCCB-B---b----bBbabbb--:0:0:1:65:0:0:0:0:10 db0d09fb48b5aea16b6c741d9ceac9dde2b03cadf26214c0c7f
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 X | | O O O O O |
| O X | | O O O O |
| | | |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | X X |
| O X | | X X X O X |
| O X | | X X X O X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 95 O: 121 X-O: 0-0
Cube: 1
X to play 65
After seeing the previous two problems in this series, you might
expect that XG would break anchor here too, and it turns out that
XG 3-ply does break anchor. However, the rollout below says that
breaking anchor is a whopper and that the ugly 8/2 6/1 is to be
preferred.
1. Rollout¹ 8/2 6/1 eq:-0.462
Player: 38.97% (G:11.38% B:0.18%)
Opponent: 61.03% (G:24.17% B:0.89%)
Confidence: ±0.016 (-0.478..-0.446) - [100.0%]
2. Rollout¹ 18/7 eq:-0.556 (-0.094)
Player: 35.88% (G:11.14% B:0.53%)
Opponent: 64.12% (G:21.35% B:0.74%)
Confidence: ±0.012 (-0.568..-0.544) - [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
3 ply incorrectly does not double after 2, 1. Not sure what, if any, effect this has but worth noting. Don't have the time or interest to look into it.
Stick
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