XGID=-BBBC-C-A-----c---bbBbcba-:0:0:1:54:0:0:0:0:10

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-+
| O O | | O X O O O O |
| O O | | O X O O O |
| O | | O |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | X X |
| | | X X X X X |
| X | | X X X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 90 O: 81 X-O: 0-0
Cube: 1
X to play 54

---
Tim Chow

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

XGID=-BBBC-C-A-----c---bbBbcba-:0:0:1:54:0:0:0:0:10

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-+
| O O | | O X O O O O |
| O O | | O X O O O |
| O | | O |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | X X |
| | | X X X X X |
| X | | X X X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 90 O: 81 X-O: 0-0
Cube: 1
X to play 54

In this sort of position, X has to judge which is the lesser evil:
giving O attacking chances, or wasting pips in the race. What I
find interesting about this particular position is that 20/11 is a
"cube provocation play." After 20/11, XG doubles as O, but after
8/3 6/2, XG does *not* double as O. That is, 20/11 "forces" O into
an inefficient double. (Though as the variant below shows, even if
X already owned the cube, XG slightly prefers 20/11 anyway.)

1. Rollout¹ 20/11 eq:-0.592
Player: 30.87% (G:2.21% B:0.03%)
Opponent: 69.13% (G:2.73% B:0.04%)
Confidence: ±0.009 (-0.602..-0.583) - [100.0%]

2. Rollout¹ 8/3 6/2 eq:-0.655 (-0.062)
Player: 29.88% (G:0.69% B:0.01%)
Opponent: 70.12% (G:1.97% B:0.02%)
Confidence: ±0.009 (-0.663..-0.646) - [0.0%]

3. Rollout¹ 8/4 6/1 eq:-0.665 (-0.073)
Player: 29.64% (G:0.66% B:0.01%)
Opponent: 70.36% (G:1.95% B:0.02%)
Confidence: ±0.008 (-0.674..-0.657) - [0.0%]

4. Rollout¹ 6/2 6/1 eq:-0.698 (-0.106)
Player: 29.29% (G:0.47% B:0.00%)
Opponent: 70.71% (G:2.85% B:0.07%)
Confidence: ±0.009 (-0.707..-0.689) - [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=-BBBC-C-A-----c---bbBbcba-:1:1:1:54:0:0:0:0:10

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-+
| O O | | O X O O O O |
| O O | | O X O O O |
| O | | O |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | X X | +---+
| | | X X X X X | | 2 |
| X | | X X X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 90 O: 81 X-O: 0-0
Cube: 2, X own cube
X to play 54

1. Rollout¹ 20/11 eq:-0.296
Player: 30.87% (G:2.21% B:0.03%)
Opponent: 69.13% (G:2.73% B:0.04%)
Confidence: ±0.005 (-0.301..-0.292) - [100.0%]

2. Rollout¹ 8/3 6/2 eq:-0.315 (-0.019)
Player: 29.87% (G:0.69% B:0.01%)
Opponent: 70.13% (G:1.97% B:0.02%)
Confidence: ±0.005 (-0.320..-0.310) - [0.0%]

3. Rollout¹ 8/4 6/1 eq:-0.322 (-0.025)
Player: 29.63% (G:0.66% B:0.01%)
Opponent: 70.37% (G:1.95% B:0.02%)
Confidence: ±0.004 (-0.326..-0.317) - [0.0%]

4. Rollout¹ 6/2 6/1 eq:-0.340 (-0.044)
Player: 29.36% (G:0.49% B:0.00%)
Opponent: 70.64% (G:3.02% B:0.07%)
Confidence: ±0.005 (-0.345..-0.335) - [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

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

XGID=---A-BD-Bab-bDa--bbb-bB-a-:0:0:1:63:0:0:0:0:10

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 O X O |
| X O O | | O O X |
| X | | |
| X | | |
| | | |
| |BAR| |
| | | |
| | | X |
| | | X |
| O O X | | X X |
| O O O X | | X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 149 O: 134 X-O: 0-0
Cube: 1
X to play 63

---
Tim Chow

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 6/25/2023 9:13 AM, Timothy Chow wrote:

XGID=---A-BD-Bab-bDa--bbb-bB-a-:0:0:1:63:0:0:0:0:10

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     O  X     O |
 | X           O  O |   | O     O  X       |
 | X                |   |                  |
 | X                |   |                  |
 |                  |   |                  |
 |                  |BAR|                  |
 |                  |   |                  |
 |                  |   | X                |
 |                  |   | X                |
 | O     O     X    |   | X  X             |
 | O     O  O  X    |   | X  X     X       |
 +12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count  X: 149  O: 134 X-O: 0-0
Cube: 1
X to play 63

Behind in the race I'd keep the anchor to maintain contact. OTOH, the
three point is a POS, so maybe getting off it post haste is the bot play.

I'll unstack the midpoint and make a third homeboard point and hope she
leaves shot or I roll boxes. 13/7 6/3.

--
Ah....Clem
The future is fun, the future is fair.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

XGID=---A-BD-Bab-bDa--bbb-bB-a-:0:0:1:63:0:0:0:0:10

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 O X O |
| X O O | | O O X |
| X | | |
| X | | |
| | | |
| |BAR| |
| | | |
| | | X |
| | | X |
| O O X | | X X |
| O O O X | | X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 149 O: 134 X-O: 0-0
Cube: 1
X to play 63

Normally in a holding game, the idea is to stay back for more contact,
and hold the anchor until we can hit a shot. But here, we have the
stronger board and are not that far behind in the pip count, so there
is value in provoking contact right away. Given how close the race is,
the 3pt anchor is a bit too deep to hold on to for much longer anyway.

In the variant below, breaking anchor carries a higher risk of getting attacked, and XG says the decision is much closer.

1. Rollout¹ 22/16 6/3 eq:-0.343
Player: 40.91% (G:9.73% B:0.46%)
Opponent: 59.09% (G:15.00% B:0.33%)
Confidence: ±0.013 (-0.356..-0.330) - [100.0%]

2. Rollout¹ 13/7 6/3 eq:-0.450 (-0.107)
Player: 37.13% (G:7.19% B:0.25%)
Opponent: 62.87% (G:7.71% B:0.21%)
Confidence: ±0.011 (-0.460..-0.439) - [0.0%]

3. Rollout¹ 13/4 eq:-0.488 (-0.146)
Player: 36.45% (G:7.12% B:0.24%)
Opponent: 63.55% (G:9.07% B:0.31%)
Confidence: ±0.011 (-0.499..-0.477) - [0.0%]

4. Rollout¹ 13/7 8/5 eq:-0.504 (-0.162)
Player: 35.84% (G:6.91% B:0.24%)
Opponent: 64.16% (G:8.47% B:0.33%)
Confidence: ±0.012 (-0.516..-0.492) - [0.0%]

5. Rollout¹ 8/2 6/3 eq:-0.517 (-0.175)
Player: 35.43% (G:6.66% B:0.23%)
Opponent: 64.57% (G:8.07% B:0.25%)
Confidence: ±0.013 (-0.530..-0.505) - [0.0%]

6. Rollout¹ 22/13 eq:-0.528 (-0.185)
Player: 35.91% (G:6.38% B:0.22%)
Opponent: 64.09% (G:12.14% B:0.17%)
Confidence: ±0.011 (-0.539..-0.517) - [0.0%]

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

eXtreme Gammon Version: 2.19.211.pre-release

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

XGID=---A-BD-Bab-bD---bcc-bB---:0:0:1:63:0:0:0:0:10

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 |
| X O O | | O O X |
| X O | | O |
| X | | |
| | | |
| |BAR| |
| | | |
| | | X |
| | | X |
| O O X | | X X |
| O O O X | | X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 149 O: 135 X-O: 0-0
Cube: 1
X to play 63

1. Rollout¹ 22/16 6/3 eq:-0.592
Player: 34.38% (G:6.11% B:0.24%)
Opponent: 65.62% (G:14.41% B:0.37%)
Confidence: ±0.006 (-0.598..-0.586) - [100.0%]

2. Rollout¹ 13/7 6/3 eq:-0.609 (-0.017)
Player: 32.86% (G:5.13% B:0.16%)
Opponent: 67.14% (G:6.60% B:0.24%)
Confidence: ±0.006 (-0.615..-0.604) - [0.0%]

¹ 5184 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.211.pre-release

---
Tim Chow

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)