Is this a backgame?

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Timothy Chow

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Sep 18, 2021, 7:25:25 PMSep 18
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XGID=-----bCC--bB-C--cbbbBbB---:0:0:1:52:0:0:0:0:10

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 X O X |
| X O O O | | O X O X |
| X O | | |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| X | | X |
| X O X | | X O |
| X O X | | X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 184 O: 147 X-O: 0-0
Cube: 1
X to play 52

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Tim Chow

ah...Clem

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Sep 20, 2021, 10:33:54 AMSep 20
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I wouldn't call this a backgame. Not enough timing and O still has four
checkers to bring around. "Mutual holding game" is more like it.

And since it looks like a holding game, I'm not going to volunteer a
shot. 13/6 for me, although Pottling with 22/15 looks sound and may be best.

Timothy Chow

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Sep 21, 2021, 10:18:46 PMSep 21
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Here, 13/6 looks plausible, but XG favors either jumping a checker
over O's prime with 22/15 (despite being 30 pips down after the roll)
or the odd-looking 13/8 6/4. Actually, I think I understand the
rationale behind 13/8 6/4---X is playing a two-way game, meaning that
he can fall back on a backgame if necessary, and can afford to play
aggressively. It's 22/15 that still looks odd to me, since I would
think that X wants to keep that back anchor for more contact.

1. Rollout¹ 22/15 eq:-0.516
Player: 37.82% (G:7.39% B:0.32%)
Opponent: 62.18% (G:16.73% B:0.58%)
Confidence: ±0.018 (-0.534..-0.498) - [50.1%]

2. Rollout¹ 13/8 6/4 eq:-0.516
Player: 38.45% (G:7.75% B:0.31%)
Opponent: 61.55% (G:17.74% B:0.58%)
Confidence: ±0.017 (-0.533..-0.499) - [49.9%]

3. Rollout¹ 13/6 eq:-0.604 (-0.088)
Player: 35.27% (G:7.05% B:0.30%)
Opponent: 64.73% (G:15.57% B:0.46%)
Confidence: ±0.016 (-0.619..-0.588) - [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

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Tim Chow
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