And if so, is it the right move?



XGID=--b-BBD-B--AbC---e-db--A--:1:-1:1:32:0:0:3:0:10

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 O | | O O X | +---+
| X O | | O O | | 2 |
| X O | | O | +---+
| O | | O |
| O | | |
| |BAR| |
| | | |
| | | X |
| | | X |
| O X | | X X X O |
| O X X | | X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 131 O: 146 X-O: 0-0
Cube: 2, O own cube
X to play 32



eXtreme Gammon Version: 2.10


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

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

On 9/8/2022 10:20 AM, ah....Clem wrote:

And if so, is it the right move?

XGID=--b-BBD-B--AbC---e-db--A--:1:-1:1:32:0:0:3:0:10

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           O    |   | O  O        X    | +---+
 | X           O    |   | O  O             | | 2 |
 | X           O    |   | O                | +---+
 |             O    |   | O                |
 |             O    |   |                  |
 |                  |BAR|                  |
 |                  |   |                  |
 |                  |   | X                |
 |                  |   | X                |
 | O           X    |   | X  X  X     O    |
 | O  X        X    |   | X  X  X     O    |
 +12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count  X: 131  O: 146 X-O: 0-0
Cube: 2, O own cube
X to play 32

X is well ahead in the race here, so running the last checker
is strategically the right idea. If X had rolled something
that would let him run to the 14pt/15pt/16pt, then I would
Pottle without hesitation. Here it's not as obvious, but
the 23pt is not a great place to sit, so I would certainly
step up with 23/21 at least. After that, 11/8 is the main
alternative to 21/18, but I would play 23/18 since it doesn't
seem any more dangerous than sitting on the 21pt.

---
Tim Chow

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

I usually think of Pottle's law as applying when you can run the last *meaningfully* (i.e. checker past the eight point), but I don't know
where I got that from or whether it's part of the aphorism.

I'm also not sure whether stepping up to the edge of the prime while
safteying an outfield blot and placing a spare on the eight point counts
as "very constructive".

But it seemed close enough to "very constructive" that I opted for that
instead of running out to the bar point. XG favors that play, but only
at the 98% confidence level after 1296 trials. So it's very close.

In the variant, I've given X a 52 to play instead of 32 and Pottling is
quite clear.


XGID=--b-BBD-B--AbC---e-db--A--:1:-1:1:32:0:0:3:0:10

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 O | | O O X | +---+
| X O | | O O | | 2 |
| X O | | O | +---+
| O | | O |
| O | | |
| |BAR| |
| | | |
| | | X |
| | | X |
| O X | | X X X O |
| O X X | | X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 131 O: 146 X-O: 0-0
Cube: 2, O own cube
X to play 32

1. Rollout¹ 23/21 11/8 eq:+0.304
Player: 66.93% (G:15.52% B:0.78%)
Opponent: 33.07% (G:7.65% B:0.21%)
Confidence: ±0.008 (+0.296..+0.312) - [98.1%]
Duration: 3 minutes 44 seconds

2. Rollout¹ 23/18 eq:+0.293 (-0.012)
Player: 67.14% (G:13.97% B:0.65%)
Opponent: 32.86% (G:7.55% B:0.29%)
Confidence: ±0.007 (+0.285..+0.300) - [1.9%]
Duration: 3 minutes 48 seconds

Opponent: 35.16% (G:7.81% B:0.19%)


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


eXtreme Gammon Version: 2.10


////////////////////
//variant
///////////////////

XGID=--b-BBD-B--AbC---e-db--A--:1:-1:1:52:0:0:3:0:10

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 O | | O O X | +---+
| X O | | O O | | 2 |
| X O | | O | +---+
| O | | O |
| O | | |
| |BAR| |
| | | |
| | | X |
| | | X |
| O X | | X X X O |
| O X X | | X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 131 O: 146 X-O: 0-0
Cube: 2, O own cube
X to play 52

1. XG Roller++ 23/16 eq:+0.407
Player: 71.79% (G:11.48% B:0.48%)
Opponent: 28.21% (G:4.73% B:0.14%)

2. XG Roller++ 23/18 13/11 eq:+0.336 (-0.071)
Player: 68.62% (G:13.29% B:0.58%)
Opponent: 31.38% (G:6.19% B:0.20%)

Opponent: 32.90% (G:7.22% B:0.19%)


eXtreme Gammon Version: 2.10


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

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