Pay now?

31 views
Skip to first unread message

Timothy Chow

unread,
May 16, 2022, 10:11:58 AMMay 16
to
XGID=----BbE-BB--cB--Bd-ca--b--:0:0:1:43:0:0:0:0:10

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 X O | | O O O |
| X X O | | O O |
| O | | O |
| O | | |
| | | |
| |BAR| |
| | | X |
| | | X |
| O | | X |
| O X X | | X O X |
| O X X | | X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 130 O: 138 X-O: 0-0
Cube: 1
X to play 43

---
Tim Chow

atila...@gmail.com

unread,
May 17, 2022, 9:17:54 AMMay 17
to
16 Mayıs 2022 Pazartesi tarihinde saat 17:11:58 UTC+3 itibarıyla Tim Chow şunları yazdı:
XGID=----BbE-BB--cB--Bd-ca--b--:0:0:1:43:0:0:3:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game, Jacoby Beaver

Pip count X: 130 O: 138 X-O: 0-0
Cube: 1
X to play 43

1. Rollout¹ 13/10 13/9 eq:+0,300
Player: 58,98% (G:4,77% B:0,15%)
Opponent: 41,02% (G:4,74% B:0,13%)
Confidence: ±0,007 (+0,293..+0,307) - [100,0%]

2. Rollout¹ 13/9 6/3 eq:+0,257 (-0,042)
Player: 57,87% (G:5,29% B:0,18%)
Opponent: 42,13% (G:5,95% B:0,17%)
Confidence: ±0,007 (+0,250..+0,265) - [0,0%]

3. Rollout¹ 16/9 eq:+0,242 (-0,058)
Player: 57,85% (G:4,89% B:0,18%)
Opponent: 42,15% (G:6,56% B:0,13%)
Confidence: ±0,007 (+0,234..+0,249) - [0,0%]

4. Rollout¹ 6/3 6/2 eq:+0,224 (-0,076)
Player: 56,94% (G:5,23% B:0,21%)
Opponent: 43,06% (G:6,60% B:0,18%)
Confidence: ±0,007 (+0,217..+0,231) - [0,0%]

5. Rollout¹ 13/6 eq:+0,221 (-0,079)
Player: 56,98% (G:5,23% B:0,18%)
Opponent: 43,02% (G:6,24% B:0,20%)
Confidence: ±0,008 (+0,213..+0,229) - [0,0%]

¹ 2592 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10

The cost of getting hit in the early or even early-mid stages of the game isn't very high. I guess that's why most moves aren't blunders.
First of all, X's outfield points do not have spares. For this reason, it seems inevitable that X will leave a blot. So X has to pay now.
To understand this, I gave X a spare checker. Variant 1.

Of course the pip numbers have changed. But it still gives an idea, and not having spare checkers is no excuse. Despite everything, the first choice is still 13/10 13/9.


XGID=----BbD-BB--cB--Cd-ca--b--:0:0:1:43:0:0:3:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game, Jacoby Beaver

Pip count X: 140 O: 138 X-O: 0-0
Cube: 1
X to play 43

1. Rollout¹ 13/10 13/9 eq:+0,128
Player: 53,39% (G:4,62% B:0,16%)
Opponent: 46,61% (G:5,78% B:0,15%)
Confidence: ±0,011 (+0,118..+0,139) - [100,0%]


2. Rollout¹ 16/9 eq:+0,103 (-0,025)
Player: 52,71% (G:4,12% B:0,15%)
Opponent: 47,29% (G:5,56% B:0,11%)
Confidence: ±0,010 (+0,093..+0,113) - [0,0%]


3. Rollout² 16/13 6/2 eq:+0,046 (-0,082)
Player: 51,34% (G:3,88% B:0,14%)
Opponent: 48,66% (G:6,31% B:0,18%)
Confidence: ±0,022 (+0,025..+0,068) - [0,0%]


4. Rollout¹ 13/9 6/3 eq:+0,044 (-0,085)
Player: 51,41% (G:5,02% B:0,21%)
Opponent: 48,59% (G:7,24% B:0,19%)
Confidence: ±0,012 (+0,032..+0,055) - [0,0%]


5. Rollout² 13/6 eq:+0,043 (-0,085)
Player: 51,22% (G:4,80% B:0,16%)
Opponent: 48,78% (G:6,60% B:0,17%)
Confidence: ±0,022 (+0,021..+0,065) - [0,0%]


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

² 324 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10

In the 2nd variant, I covered O's blot on the 5 point . Now his homeboard is stronger. And it's time to play safe.
In summary, your opponent's weak homeboard says pay now.

Variant 2

XGID=----BbE-BB--cB--Bd-bb--b--:0:0:1:43:0:0:3:0:10

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-+
| X X O | | O O O |
| X X O | | O O O |
| O | | |
| O | | |
| | | |
| |BAR| |
| | | X |
| | | X |
| O | | X |
| O X X | | X O X |
| O X X | | X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 130 O: 137 X-O: 0-0
Cube: 1
X to play 43

1. Rollout¹ 6/3 6/2 eq:+0,184
Player: 55,74% (G:4,96% B:0,19%)
Opponent: 44,26% (G:6,98% B:0,15%)
Confidence: ±0,011 (+0,174..+0,195) - [99,7%]


2. Rollout¹ 6/2 4/1 eq:+0,162 (-0,022)
Player: 55,14% (G:4,52% B:0,14%)
Opponent: 44,86% (G:7,43% B:0,19%)
Confidence: ±0,012 (+0,150..+0,174) - [0,3%]

3. Rollout¹ 13/10 13/9 eq:+0,145 (-0,040)
Player: 54,48% (G:6,23% B:0,18%)
Opponent: 45,52% (G:7,07% B:0,24%)
Confidence: ±0,010 (+0,134..+0,155) - [0,0%]


4. Rollout¹ 13/9 6/3 eq:+0,095 (-0,089)
Player: 53,43% (G:5,45% B:0,17%)
Opponent: 46,57% (G:7,74% B:0,22%)
Confidence: ±0,010 (+0,085..+0,105) - [0,0%]


5. Rollout² 16/9 eq:+0,091 (-0,093)
Player: 53,44% (G:4,46% B:0,18%)
Opponent: 46,56% (G:8,59% B:0,15%)
Confidence: ±0,019 (+0,072..+0,110) - [0,0%]

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

² 324 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10

Timothy Chow

unread,
May 19, 2022, 9:57:19 AMMay 19
to
atilamalcok has already rolled out the position and even anticipated my
variant! I also like atilamalcok's other variant, which I did not think
to examine.

In Michy's eulogy for Falafel, he attributed to Falafel the term
"island" (see page 5):

http://www.world-backgammon-association.com/attachments/article/131/I-Mourn-for-Falafel.pdf

An "island" is a position in which every point in your outer board is
stripped. The position above is an example. Falafel emphasized that
islands are bad. So X is willing to take some risk (but of course not
an excessive amount of risk) to get rid of the island formation.

1. Rollout¹ 13/10 13/9 eq:+0.291
Player: 58.87% (G:4.70% B:0.14%)
Opponent: 41.13% (G:4.84% B:0.15%)
Confidence: ±0.009 (+0.282..+0.301) - [100.0%]

2. Rollout¹ 16/9 eq:+0.250 (-0.042)
Player: 57.96% (G:4.79% B:0.20%)
Opponent: 42.04% (G:6.64% B:0.13%)
Confidence: ±0.010 (+0.239..+0.260) - [0.0%]

3. Rollout¹ 13/9 6/3 eq:+0.244 (-0.048)
Player: 57.79% (G:5.08% B:0.14%)
Opponent: 42.21% (G:6.10% B:0.18%)
Confidence: ±0.010 (+0.234..+0.254) - [0.0%]

4. Rollout¹ 6/3 6/2 eq:+0.209 (-0.082)
Player: 56.89% (G:5.44% B:0.22%)
Opponent: 43.11% (G:6.87% B:0.17%)
Confidence: ±0.009 (+0.200..+0.218) - [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=----BbE-BB--cB--Bd-bb--b--:0:0:1:43:0:0:0:0:10

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 X O | | O O O |
| X X O | | O O O |
| O | | |
| O | | |
| | | |
| |BAR| |
| | | X |
| | | X |
| O | | X |
| O X X | | X O X |
| O X X | | X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 130 O: 137 X-O: 0-0
Cube: 1
X to play 43

1. Rollout¹ 6/3 6/2 eq:+0.178
Player: 55.79% (G:4.98% B:0.21%)
Opponent: 44.21% (G:7.13% B:0.19%)
Confidence: ±0.005 (+0.173..+0.183) - [100.0%]

2. Rollout¹ 6/2 4/1 eq:+0.166 (-0.012)
Player: 55.28% (G:4.62% B:0.15%)
Opponent: 44.72% (G:7.54% B:0.18%)
Confidence: ±0.005 (+0.161..+0.171) - [0.0%]

3. Rollout¹ 13/10 13/9 eq:+0.153 (-0.025)
Player: 54.70% (G:6.34% B:0.19%)
Opponent: 45.30% (G:7.17% B:0.23%)
Confidence: ±0.005 (+0.148..+0.158) - [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
Reply all
Reply to author
Forward
0 new messages