Prime versus prime

[Timothy Chow]

XGID=-b--ACD-C----B--babccb--B-:1:1:1:51:0:0:0:0:10

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 |
| X O O | | O O O X |
| | | O O |
| | | |
| | | |
| |BAR| |
| | | |
| | | X |
| X | | X X | +---+
| X | | X X O | | 2 |
| X | | X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 141 O: 129 X-O: 0-0
Cube: 2, X own cube
X to play 51

---
Tim Chow

[peps...@gmail.com]

It's not very QF-friendly but surely the most natural idea is to extend the prime by 5/4 and then 13/8 is the obvious 5 so I'll play that.
I can't totally rule out making the 3 point though. So perhaps that's the XG play.
Anyway, 13/8 5/4 is my response. It's not my answer -- I don't have an answer. But it is my response.

Paul

[Timothy Chow]

X is losing the priming battle, so that justifies taking some risks.
The fact that O's 2's are somewhat duplicated (to hit and make her
own 3pt) makes some difference, but even without this duplication,
XG favors slotting 8/3 (see variant).

1. Rollout¹ 8/3 5/4 eq:-0.177
Player: 39.78% (G:12.52% B:0.73%)
Opponent: 60.22% (G:23.20% B:2.39%)
Confidence: ±0.012 (-0.189..-0.165) - [100.0%]

2. Rollout¹ 13/8 5/4 eq:-0.266 (-0.089)
Player: 35.80% (G:10.42% B:0.53%)
Opponent: 64.20% (G:20.83% B:1.72%)
Confidence: ±0.010 (-0.276..-0.257) - [0.0%]

3. Rollout¹ 8/3 4/3 eq:-0.283 (-0.106)
Player: 35.22% (G:10.88% B:0.63%)
Opponent: 64.78% (G:21.11% B:1.65%)
Confidence: ±0.011 (-0.293..-0.272) - [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=-b--ACD-C----B--babcbc--B-:1:1:1:51:0:0:0:0:10

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 |
| X O O | | O O O X |
| | | O O |
| | | |
| | | |
| |BAR| |
| | | |
| | | X |
| X | | X X | +---+
| X | | X X O | | 2 |
| X | | X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+

Pip count X: 141 O: 128 X-O: 0-0

Cube: 2, X own cube
X to play 51

1. Rollout¹ 8/3 5/4 eq:-0.164
Player: 40.23% (G:12.67% B:0.79%)
Opponent: 59.77% (G:23.17% B:2.56%)
Confidence: ±0.011 (-0.175..-0.153) - [100.0%]

2. Rollout¹ 13/8 5/4 eq:-0.209 (-0.045)
Player: 37.68% (G:11.33% B:0.65%)
Opponent: 62.32% (G:20.56% B:1.56%)
Confidence: ±0.009 (-0.219..-0.200) - [0.0%]

3. Rollout¹ 8/3 4/3 eq:-0.239 (-0.074)
Player: 36.71% (G:11.16% B:0.61%)
Opponent: 63.29% (G:20.68% B:1.72%)
Confidence: ±0.010 (-0.248..-0.229) - [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