Early(ish) blitz cube

[Timothy Chow]

XGID=aa-BBAC-A---cD-b-a-eb---B-:0:0:1:00:0:0:0:0:10

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 X |
| X | | O |
| X | | O |
| | | O |
| |BAR| |
| | O | |
| | | |
| O | | X |
| O | | X X X |
| O X | | X X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 145 O: 156 X-O: 0-0
Cube: 1
X on roll, cube action

---
Tim Chow

[peps...@gmail.com]

D/T but with much more confidence in the D, than the T. D/P would not surprise me at all.
If we make the 5 point and the opponent dances, we lose our market, so it must be a double.

But can the opponent take? The opponent has plenty of potential to get a good game going,
with us having 2 men stuck back, and with the opponent's ownership of their 5 point.
I don't think they need to give up yet.

D/T but a hesitant one, because the theme of Tim's story might well be "I was surprised this was a pass."

At my work, I need to label each of my assignments with one of the following categories: Task/ Story/ Bug Fix.
It's not at all unlike this newsgroup.
Bug issues have been discussed, as there are sometimes underlying stories which motivate the threads.
It can be tricky to give the correct label to the assignments.
So I would ask "Is this a Task or a Story?" (There's no way it's a bug fix.)
As a Task, I can live with my D/T assessment.
But is it a Story? If it's a story, the story is likely to be a surprised-by-the-pass story.
Anyway, I'm going with D/T but my confidence level is only very slightly more than 50%.
(Since I'm close to certain that it's a cube, I must be at least 50% certain in the evaluation.)

Paul

[ah....Clem]

X still holds his own ace point, and that's often a signal that it's a
take or a hold. But O is about to be blown off the board if X covers the
five point and O dances. Lots of gammons afoot, so I think X has to ship
it here. The take seems close, but I'll say take due to O's made five
point and X's checkers stuck on the ace point.

D/T.

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

[Timothy Chow]

Paul's speculation was correct---I was surprised that XG thought
this was a pass. Here are the features of the position that I
ticked off:

- Nine checkers in the zone.
- O's blot is on my 1pt.
- O has made her 5pt.
- My two back checkers are still on the 24pt.
- I have only a slight race lead.

Other positions that have these features are typically takes,
though maybe close takes. So I was amazed that the rollout below
indicated a big pass. One feature that I neglected to take into
account was O's blot on her 8pt. How much difference do you think
it makes to shift a checker from O's 10pt to her 8pt? I didn't
think it would make a huge difference, but the XG rollout below
says it decreases O's equity by about 0.2, pushing X into take
territory.

Analyzed in Rollout
No double
Player Winning Chances: 68.76% (G:37.73% B:2.20%)
Opponent Winning Chances: 31.24% (G:8.64% B:0.58%)
Double/Take
Player Winning Chances: 68.89% (G:38.54% B:2.12%)
Opponent Winning Chances: 31.11% (G:8.77% B:0.58%)

Cubeful Equities:
No double: +0.871 (-0.129)
Double/Take: +1.137 (+0.137)
Double/Pass: +1.000

Best Cube action: Double / Pass

Rollout:
1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.014 (+0.857..+0.885)
Confidence Double: ± 0.019 (+1.118..+1.156)

eXtreme Gammon Version: 2.19.211.pre-release

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

XGID=aa-BBAC-A---cD-a-b-eb---B-:0:0:1:00:0:0:0:0:10

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 X |
| X | | O |
| X | | O |
| | | O |
| |BAR| |
| | O | |
| | | |
| O | | X |
| O | | X X X |
| O X | | X X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+

Pip count X: 145 O: 154 X-O: 0-0

Cube: 1
X on roll, cube action

Analyzed in Rollout
No double
Player Winning Chances: 66.39% (G:34.68% B:1.78%)
Opponent Winning Chances: 33.61% (G:9.61% B:0.60%)
Double/Take
Player Winning Chances: 66.59% (G:34.97% B:1.80%)
Opponent Winning Chances: 33.41% (G:9.65% B:0.60%)

Cubeful Equities:
No double: +0.763 (-0.163)
Double/Take: +0.926
Double/Pass: +1.000 (+0.074)

Best Cube action: Double / Take

Rollout:
5184 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.008 (+0.755..+0.770)
Confidence Double: ± 0.012 (+0.914..+0.937)

eXtreme Gammon Version: 2.19.211.pre-release

---
Tim Chow

[peps...@gmail.com]

...

I'm not at all surprised at this 0.2 difference. I can't say I would have guessed
exactly this number, but I don't think I would have gone lower. I would probably have guessed
in the 0.2 <= x <= 0.3 range.
This blot is one of the reasons my (wrong) take was so tentative.

Paul

[peps...@gmail.com]

Sorry, I misread. 0.2 to 0.3 was my estimate of the difference between the original position and removing the blot
completely (of course, this depends somewhat on where the blot is removed to). Like you, I would have estimated
a smaller difference from a shift from 8 to 10. I would have realised that this version is more likely to be a take, but
a smaller difference seems, also to me, like a good guess.

Paul

[Philippe Michel]

On 2022-10-25, Timothy Chow <tchow...@yahoo.com> wrote:

> XGID=aa-BBAC-A---cD-b-a-eb---B-:0:0:1:00:0:0:0:0:10
>
> 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 X |
> | X | | O |
> | X | | O |
> | | | O |
> | |BAR| |
> | | O | |
> | | | |
> | O | | X |
> | O | | X X X |
> | O X | | X X X X O |
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 145 O: 156 X-O: 0-0
> Cube: 1
> X on roll, cube action
>
> Paul's speculation was correct---I was surprised that XG thought

> this was a pass. [...]

Your further discussion suggests the subject was sincere this time.
Maybe this is part of the issue, because X really has a two-way game:
his front position is a fine priming formation as well, far better than
O's in this regard.

[Timothy Chow]

On 10/31/2022 3:54 PM, Philippe Michel wrote:
> Your further discussion suggests the subject was sincere this time.
> Maybe this is part of the issue, because X really has a two-way game:
> his front position is a fine priming formation as well, far better than
> O's in this regard.

It's true that X can prime as well. However, I still believe that this
position should mainly be thought of as a blitz. The primary reason
it's a pass, I believe, is the high gammon rate, which comes mostly from
blitzing rather than priming.

---
Tim Chow