Unlimited game cube action

[ah....Clem]

XGID=a----BDBaAA-cDb--c-c-bA---:0:0:1:00:0:0:0:0:10

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 |
| X O O | | O O |
| X O | | O |
| X | | |
| | | |
| |BAR| |
| | O | |
| | | X |
| O | | X |
| O X | | X X |
| O X X O X | | X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 141 O: 153 X-O: 0-0
Cube: 1
X on roll, cube action



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

[Timothy Chow]

On 9/24/2023 11:52 AM, ah....Clem wrote:
>
> XGID=a----BDBaAA-cDb--c-c-bA---:0:0:1:00:0:0:0:0:10
>
> 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       |
>  | X  O        O    |   | O     O          |
>  | X           O    |   | O                |
>  | X                |   |                  |
>  |                  |   |                  |
>  |                  |BAR|                  |
>  |                  | O |                  |
>  |                  |   | X                |
>  | O                |   | X                |
>  | O              X |   | X  X             |
>  | O     X  X  O  X |   | X  X             |
>  +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count  X: 141  O: 153 X-O: 0-0
> Cube: 1
> X on roll, cube action

X has ten checkers in the zone and has escaped one of his back
checkers. He has a clear lead in the pip count and is threatening
to hit a second checker. Although X has only a two-point board at
the moment, I don't think O can take this one. In fact, maybe X
is too good. I usually double this sort of position OTB but am
often surprised when XG dings me, saying it's TG. Let me go with
TG/pass.

---
Tim Chow

[ah....Clem]

Like the previous blitz or prime position, this one is from the facebook
humans vs XG page where some very skilled players (NeilKaz, Will
Snellings) got it wrong. I did too.

The actual position used Jacoby, so the TG question was moot. I changed
it here because it makes the position more interesting. The consensus
was that it was a pass due to the liklihood that O gets blitzed off the
board, but XG says it's a medium error to pass this one.

Comments from moderator David Potter are below.

XGID=a----BDBaAA-cDb--c-c-bA---:0:0:1:00:0:0:0:0:10

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 |
| X O O | | O O |
| X O | | O |
| X | | |
| | | |
| |BAR| |
| | O | |
| | | X |
| O | | X |
| O X | | X X |
| O X X O X | | X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 141 O: 153 X-O: 0-0
Cube: 1
X on roll, cube action

Analyzed in Rollout
No double
Player Winning Chances: 68.48% (G:27.67% B:0.97%)
Opponent Winning Chances: 31.52% (G:6.53% B:0.27%)
Double/Take
Player Winning Chances: 68.47% (G:28.38% B:1.00%)
Opponent Winning Chances: 31.53% (G:6.75% B:0.30%)

Cubeless Equities: No Double=+0.588, Double=+1.185

Cubeful Equities:
No double: +0.821 (-0.120)
Double/Take: +0.941
Double/Pass: +1.000 (+0.059)

Best Cube action: Double / Take

Rollout:
1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.015 (+0.806..+0.837)
Confidence Double: ± 0.020 (+0.921..+0.961)

Double Decision confidence: 100.0%
Take Decision confidence: 100.0%

Duration: 9 minutes 07 seconds

eXtreme Gammon Version: 2.10




We vote Double/Pass but a 2K roll out says it's quite an error to pass
this. Let's look at the board to see what's going on.

White (X) has a two point board and has a triple shot at Black's (O's)
blot. It looks strong but black isn't doing too badly. Black has made
the 4pt, has no dead checkers and a nice outfield structure. White still
has a checker to bring around and it's hard for White to hit and make
another inner board point next go so that gives Black some time to make
an anchor or fight back in some way. Black has some good assets here and
has a fairly easy take while White is not overwhelmingly strong.