14 Haziran 2022 Salı tarihinde saat 15:38:53 UTC+3 itibarıyla Tim Chow şunları yazdı:
XGID=--BbCBB-D---b------cBcbba-:0:0:1:63:0:0:0:0:10
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 X O O O O |
| | | O X O O O |
| | | O O |
| | | |
| | | |
| |BAR| |
| | | |
| X | | |
| X | | X |
| O X | | X X X O X |
| O X | | X X X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 110 O: 111 X-O: 0-0
Cube: 1
X to play 63
Kit Woolsey has a nice article on breaking anchor.
https://www.bkgm.com/articles/GOL/Sep02/anchor.htm
Here, timing considerations might seem to suggest breaking anchor.
X is ahead in the pip count and if he doesn't break anchor now, he
has to dump a checker to the 2pt, and he might be forced to break
anchor under more unfavorable conditions next turn. Also, O's board,
while pretty strong, has a blot in it.
However, the rollout below says that 20/11 is a whopper. The thing
is that O's timing is also precarious. If X sits tight, O may very
well be forced to compromise her position immediately. If we give
O some more timing (see variant) then the decision becomes much
closer.
1. Rollout¹ 8/5 8/2 eq:+0.427
Player: 61.13% (G:13.83% B:0.33%)
Opponent: 38.87% (G:7.32% B:0.19%)
Confidence: ±0.013 (+0.414..+0.440) - [100.0%]
2. Rollout¹ 20/11 eq:+0.302 (-0.125)
Player: 59.92% (G:14.27% B:0.70%)
Opponent: 40.08% (G:11.12% B:0.15%)
Confidence: ±0.012 (+0.290..+0.315) - [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=--BbCBB-D---c------cBbbba-:0:0:1:63:0:0:0:0:10
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 X O O O O |
| | | O X O O O |
| | | O |
| | | |
| | | |
| |BAR| |
| | | |
| X | | |
| O X | | X |
| O X | | X X X O X |
| O X | | X X X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 110 O: 120 X-O: 0-0
Cube: 1
X to play 63
1. Rollout¹ 8/5 8/2 eq:+0.354
Player: 59.92% (G:13.34% B:0.49%)
Opponent: 40.08% (G:8.54% B:0.20%)
Confidence: ±0.005 (+0.349..+0.359) - [100.0%]
2. Rollout¹ 20/11 eq:+0.330 (-0.024)
Player: 59.78% (G:14.54% B:0.62%)
Opponent: 40.22% (G:10.82% B:0.16%)
Confidence: ±0.006 (+0.324..+0.335) - [0.0%]
3. Rollout¹ 8/2 4/1 eq:+0.296 (-0.057)
Player: 58.15% (G:14.22% B:0.43%)
Opponent: 41.85% (G:10.01% B:0.27%)
Confidence: ±0.005 (+0.291..+0.302) - [0.0%]
¹ 5184 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
Here we should not overlook the pretty aces awarded to O after 20/11. (Variant 2)
Also after 8/5, the spare checkers on the 4 and 5 work well together. If we move the spare checker on the point 4 to point 2, both moves are close. Therefore, the spare checker on the 4 point also have an effect on the decision. (variant 3)
Variant 2
XGID=--BbCBB-D---c------bBcbba-:0:0:1:63:0:0:3:0:10
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game, Jacoby Beaver
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O X O O O O |
| | | O X O O O |
| | | O |
| | | |
| | | |
| |BAR| |
| | | |
| X | | |
| O X | | X |
| O X | | X X X O X |
| O X | | X X X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 110 O: 118 X-O: 0-0
Cube: 1
X to play 63
1. XG Roller++ 20/11 eq:+0,585
Player: 65,29% (G:12,81% B:0,45%)
Opponent: 34,71% (G:6,10% B:0,10%)
2. XG Roller++ 8/5 8/2 eq:+0,445 (-0,140)
Player: 62,06% (G:14,37% B:0,44%)
Opponent: 37,94% (G:7,50% B:0,18%)
3. 2-ply 8/2 4/1 eq:+0,364 (-0,221)
Player: 59,59% (G:15,73% B:0,26%)
Opponent: 40,41% (G:7,67% B:0,17%)
4. 2-ply 20/14 8/5 eq:+0,337 (-0,248)
Player: 58,70% (G:15,37% B:0,56%)
Opponent: 41,30% (G:10,42% B:0,24%)
5. 2-ply 20/17 8/2 eq:+0,261 (-0,324)
Player: 56,37% (G:17,14% B:0,61%)
Opponent: 43,63% (G:11,51% B:0,28%)
Variant 3
XGID=--CbBBB-D---b------cBcbba-:0:0:1:63:0:0:3:0:10
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game, Jacoby Beaver
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O X O O O O |
| | | O X O O O |
| | | O O |
| | | |
| | | |
| |BAR| |
| | | |
| X | | |
| X | | X |
| O X | | X X X O X |
| O X | | X X X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 108 O: 111 X-O: 0-0
Cube: 1
X to play 63
1. Rollout¹ 20/11 eq:+0,259
Player: 58,63% (G:14,01% B:0,66%)
Opponent: 41,37% (G:11,05% B:0,17%)
Confidence: ±0,012 (+0,247..+0,271) - [99,4%]
2. Rollout¹ 8/5 8/2 eq:+0,240 (-0,020)
Player: 56,19% (G:13,09% B:0,31%)
Opponent: 43,81% (G:8,81% B:0,26%)
Confidence: ±0,010 (+0,230..+0,249) - [0,6%]
Duration: 4 minutes 28 seconds
3. 2-ply 20/14 8/5 eq:+0,054 (-0,205)
Player: 50,82% (G:16,72% B:0,85%)
Opponent: 49,18% (G:16,09% B:0,35%)
4. 2-ply 20/17 20/14 eq:+0,019 (-0,240)
Player: 50,61% (G:13,90% B:0,69%)
Opponent: 49,39% (G:15,98% B:0,34%)
5. 1-ply 20/17 8/2 eq:-0,073 (-0,333)
Player: 48,71% (G:11,30% B:0,37%)
Opponent: 51,29% (G:15,08% B:0,34%)
¹ 1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
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