XGID=-AAa-b-----------abbbbba-B:1:-1:-1:00:5:2:3:0:10
X:eXtremeGammon O:Daniel

Score is X:2 O:5. Unlimited Game, Jacoby Beaver
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | X X O O |
| | | X |
| | | |
| | | |
| | | |
| |BAR| |
| | O | |
| | O | |
| | | | +---+
| X | | X X X X | | 2 |
| X X | | X X X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 122 O: 53 X-O: 2-5
Cube: 2, X own cube
X on roll, cube action

"peps...@gmail.com" <pepstein5@gmail.com> writes:

> XGID=-AAa-b-----------abbbbba-B:1:-1:-1:00:5:2:3:0:10
> X:eXtremeGammon O:Daniel
>
> Score is X:2 O:5. Unlimited Game, Jacoby Beaver
> +13-14-15-16-17-18------19-20-21-22-23-24-+
> | | | X X O O |
> | | | X |
> | | | |
> | | | |
> | | | |
> | |BAR| |
> | | O | |
> | | O | |
> | | | | +---+
> | X | | X X X X | | 2 |
> | X X | | X X X X X | +---+
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 122 O: 53 X-O: 2-5
> Cube: 2, X own cube
> X on roll, cube action

To me it looks considerably better than a coup classique, even though
the full prime is not yet complete. But what can happen? If my blot on
point 2 is hit, I could bring back a third and later even fourth
checker. Two of O's checkers are already on the bar, so she has not
anchored. And even if she anchors, all three conditions for a trap play,
i.e.,

1. Opponent has crashed.
2. Opponent has two checkers behind your prime.
3. You have men back to hit any refuguees.

are fulfilled.

Redouble, pass.

Axel

On 5/21/2021 5:36 PM, peps...@gmail.com wrote:
> XGID=-AAa-b-----------abbbbba-B:1:-1:-1:00:5:2:3:0:10
> X:eXtremeGammon O:Daniel
>
> Score is X:2 O:5. Unlimited Game, Jacoby Beaver
> +13-14-15-16-17-18------19-20-21-22-23-24-+
> | | | X X O O |
> | | | X |
> | | | |
> | | | |
> | | | |
> | |BAR| |
> | | O | |
> | | O | |
> | | | | +---+
> | X | | X X X X | | 2 |
> | X X | | X X X X X | +---+
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 122 O: 53 X-O: 2-5
> Cube: 2, X own cube
> X on roll, cube action

It does look a lot like a position from Wachtel's book.
Wachtel's book is a real gem but I have not bothered trying
to learn what it says about positions like these since they
come up so rarely.

However, taking a second look, I think this is a clear RD/P
and I'm not sure there's anything like this in Wachtel's book.
In particular, all those extra X checkers in O's board don't
like Wachtelian.

---
Tim Chow

On Saturday, May 22, 2021 at 11:11:26 PM UTC+1, Tim Chow wrote:
> On 5/21/2021 5:36 PM, peps...@gmail.com wrote:
> > XGID=-AAa-b-----------abbbbba-B:1:-1:-1:00:5:2:3:0:10
> > X:eXtremeGammon O:Daniel
> >
> > Score is X:2 O:5. Unlimited Game, Jacoby Beaver
> > +13-14-15-16-17-18------19-20-21-22-23-24-+
> > | | | X X O O |
> > | | | X |
> > | | | |
> > | | | |
> > | | | |
> > | |BAR| |
> > | | O | |
> > | | O | |
> > | | | | +---+
> > | X | | X X X X | | 2 |
> > | X X | | X X X X X | +---+
> > +12-11-10--9--8--7-------6--5--4--3--2--1-+
> > Pip count X: 122 O: 53 X-O: 2-5
> > Cube: 2, X own cube
> > X on roll, cube action
> It does look a lot like a position from Wachtel's book.
> Wachtel's book is a real gem but I have not bothered trying
> to learn what it says about positions like these since they
> come up so rarely.
>
> However, taking a second look, I think this is a clear RD/P
> and I'm not sure there's anything like this in Wachtel's book.
> In particular, all those extra X checkers in O's board don't
> like Wachtelian.

Yes, all three of us got this right. I had this position OTB
(which means that it almost certainly didn't occur in a Wachtel book
because the coincidence would have been extraordinary).
I correctly passed, but XG's analysis called my pass an error so
I vindicated myself with the rollout.
Interestingly, holding doesn't seem to lose a significant amount
of equity, presumably because there are too few market gainers.
So this is a case where the trick of suckering your opponent into a
bad take can be played without any downside, if you suspect that your
opponent will drop now but will take if they enter a checker on their
next roll.

Hmm, maybe those thoughts are wrong. I see a more likely explanation
for XG's verdict that holding isn't an error. Recall that XG wrongly sees this
as a take. So the holding equity is probably artificially high because it includes
a lot of bad takes by O. Holding is probably pretty bad, actually.

Paul

Analyzed in Rollout
No redouble
Player Winning Chances: 80.38% (G:0.00% B:0.00%)
Opponent Winning Chances: 19.62% (G:1.17% B:0.34%)
Redouble/Take
Player Winning Chances: 81.04% (G:0.00% B:0.00%)
Opponent Winning Chances: 18.96% (G:0.87% B:0.14%)

Cubeless Equities: No Double=+0.592, Double=+1.221

Cubeful Equities:
No redouble: +0.992 (-0.008)
Redouble/Take: +1.111 (+0.111)
Redouble/Pass: +1.000

Best Cube action: Redouble / Pass

On Sunday, May 23, 2021 at 4:26:40 AM UTC-4, peps...@gmail.com wrote:
> On Saturday, May 22, 2021 at 11:11:26 PM UTC+1, Tim Chow wrote:
> > On 5/21/2021 5:36 PM, peps...@gmail.com wrote:
> > > XGID=-AAa-b-----------abbbbba-B:1:-1:-1:00:5:2:3:0:10
> > > X:eXtremeGammon O:Daniel
> > >
> > > Score is X:2 O:5. Unlimited Game, Jacoby Beaver
> > > +13-14-15-16-17-18------19-20-21-22-23-24-+
> > > | | | X X O O |
> > > | | | X |
> > > | | | |
> > > | | | |
> > > | | | |
> > > | |BAR| |
> > > | | O | |
> > > | | O | |
> > > | | | | +---+
> > > | X | | X X X X | | 2 |
> > > | X X | | X X X X X | +---+
> > > +12-11-10--9--8--7-------6--5--4--3--2--1-+
> > > Pip count X: 122 O: 53 X-O: 2-5
> > > Cube: 2, X own cube
> > > X on roll, cube action
> > It does look a lot like a position from Wachtel's book.
> > Wachtel's book is a real gem but I have not bothered trying
> > to learn what it says about positions like these since they
> > come up so rarely.
> >
> > However, taking a second look, I think this is a clear RD/P
> > and I'm not sure there's anything like this in Wachtel's book.
> > In particular, all those extra X checkers in O's board don't
> > like Wachtelian.
> Yes, all three of us got this right. I had this position OTB
> (which means that it almost certainly didn't occur in a Wachtel book
> because the coincidence would have been extraordinary).
> I correctly passed, but XG's analysis called my pass an error so
> I vindicated myself with the rollout.
> Interestingly, holding doesn't seem to lose a significant amount
> of equity, presumably because there are too few market gainers.
> So this is a case where the trick of suckering your opponent into a
> bad take can be played without any downside, if you suspect that your
> opponent will drop now but will take if they enter a checker on their
> next roll.
>
> Hmm, maybe those thoughts are wrong. I see a more likely explanation
> for XG's verdict that holding isn't an error. Recall that XG wrongly sees this
> as a take. So the holding equity is probably artificially high because it includes
> a lot of bad takes by O. Holding is probably pretty bad, actually.
>
> Paul
>
> Analyzed in Rollout
> No redouble
> Player Winning Chances: 80.38% (G:0.00% B:0.00%)
> Opponent Winning Chances: 19.62% (G:1.17% B:0.34%)
> Redouble/Take
> Player Winning Chances: 81.04% (G:0.00% B:0.00%)
> Opponent Winning Chances: 18.96% (G:0.87% B:0.14%)
>
> Cubeless Equities: No Double=+0.592, Double=+1.221
>
> Cubeful Equities:
> No redouble: +0.992 (-0.008)
> Redouble/Take: +1.111 (+0.111)
> Redouble/Pass: +1.000
>
> Best Cube action: Redouble / Pass

Holding isn't really an error because it will be d/p next turn and likely the turn after that and the turn after that for that matter. No real equity to be lost.

Stick

On 5/21/2021 5:36 PM, peps...@gmail.com wrote:
> XGID=-AAa-b-----------abbbbba-B:1:-1:-1:00:5:2:3:0:10
> X:eXtremeGammon O:Daniel
>
> Score is X:2 O:5. Unlimited Game, Jacoby Beaver
> +13-14-15-16-17-18------19-20-21-22-23-24-+
> | | | X X O O |
> | | | X |
> | | | |
> | | | |
> | | | |
> | |BAR| |
> | | O | |
> | | O | |
> | | | | +---+
> | X | | X X X X | | 2 |
> | X X | | X X X X X | +---+
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 122 O: 53 X-O: 2-5
> Cube: 2, X own cube
> X on roll, cube action
>

Well, it's certainly not TG. And it sure looks like a cube, despite O
having 11 off and ahead by 70 pips. Usually two closed out on the bar is
a big pass - O is not closed out, but even after 11 she still has a long
way to go. Since I'm not sure about the take, it must be a cube. I think
I'd let this one go, but won't be surprised if XG says take.

R/P

On 5/24/2021 6:16 PM, ah...Clem wrote:
> On 5/21/2021 5:36 PM, peps...@gmail.com wrote:
>> XGID=-AAa-b-----------abbbbba-B:1:-1:-1:00:5:2:3:0:10
>> X:eXtremeGammon O:Daniel
>>
>> Score is X:2 O:5. Unlimited Game, Jacoby Beaver
>> +13-14-15-16-17-18------19-20-21-22-23-24-+
>> | | | X X O O |
>> | | | X |
>> | | | |
>> | | | |
>> | | | |
>> | |BAR| |
>> | | O | |
>> | | O | |
>> | | | | +---+
>> | X | | X X X X | | 2 |
>> | X X | | X X X X X | +---+
>> +12-11-10--9--8--7-------6--5--4--3--2--1-+
>> Pip count X: 122 O: 53 X-O: 2-5
>> Cube: 2, X own cube
>> X on roll, cube action
>>
>
> Well, it's certainly not TG. And it sure looks like a cube, despite O
> having 11 off and ahead by 70 pips. Usually two closed out on the bar is
> a big pass - O is not closed out, but even after 11 she still has a long
> way to go. Since I'm not sure about the take, it must be a cube. I think
> I'd let this one go, but won't be surprised if XG says take.

I'm not sure exactly what you meant by "Usually two closed out on the
bar is a big pass," but two closed out on the bar with 13 checkers off
is usually ND/T. Maybe you meant two closed out on the bar with only
11 checkers off.

---
Tim Chow