Gammonfever BG Quiz - Position #6

[Micke Nilsson]

O on roll, Cube or no Cube? And please, no bot solutions right away :o)

Money session. Score X-O: 0-0

O on roll, cube action
+-1--2--3--4--5--6--------7--8--9-10-11-12-+
| X X O | | O O X |
| O | | O O X |
| O | | O X | S
| O | | X | n
| O | | X | o
| |BAR| | w
| | | | i
| X | | | e
| X | | O |
| X X | | O X O |
| X X | | O X O |
+24-23-22-21-20-19-------18-17-16-15-14-13-+
Pipcount X: 154 O: 143 X-O: 0-0/Money (1)
CubeValue: 1

[Komodo]

This position looks interesting. O has some advantage, but it looks far
from a double yet. If snowie says double/take and my opponent does
that, I would be suspicious.

[Zorba]

There's this sort of "rule" that says that a double-six as your first
roll isn't quite enough to double; you need one more improvement. This
assumes your opponent doesn't have anything really worthwhile (7pt,
5pt, 4pt..advanced anchor or whatever).

Here, X made the threepoint. Not that valuable, but still worth
something. Both backcheckers advanced looks like a slight advantage to
me. The opportunities this gives outweigh the risks I think.

Anyway, I'd be surprised if this is a double.

I agree with Komodo that it could be suspicious if O doubles here. That
is, IF SW evaluation says double AND a rollout says no double by at
least 0.04 or so.

--
_
/
_ orba

[Philippe Michel]

No double. 6-6 is a nice start, but not nearly enough to double immediatly
in a money game (or at a "normal" score in a match). Moreover, X made a
moderately useful start with his 3pt.

On the other hand, I would not be surprised at all if an opponent happened
to double in this kind of situation. In fact, I see it quite often. This
must be steaming, but probably not a big error.

A double by Snowie would be somewhat more surprising, but hardly shocking.
The slightly unusual feature of the position is the advanced X backmen
(instead of a more common split like 24/21 with 6/4 or 13/11). Maybe they
will be pointed on too often and weaken X position enough for it to be a
double ?

[Grunty]

I would double.
As Philippe said, there are many pointing rolls, but I consider them
enough to justify a double. O gains great momentum getting those rolls.

The bad thing for X is his lack of an anchor; should he had one,
*anywhere* from 24 to 20 point, this would be no-double.

Paradoxically, I consider the fact both checkers being advanced, more
of a crucial disadvantage than a dynamic factor. They just offer more
targets, and the only solid argument inviting for a double. Should
*one* of them stands on the 24 or perhaps even on the 23 point, would
shift my evaluation to no-double, since the enhanced board coverage
would prevent O from playing safe non-pointing rolls behind them.

The only X's asset, his 3 point, has little containment value in case
he manages to hit a checker. This makes a very long shot for him to
turn the game around.

Of course, X has an easy take.
If he manages to make an anchor somewhere, he'll get a good holding
position.
He is not risking many gammons here.

Maybe I just have an optimistic vision of the game: double/take.

[David C. Ullrich]

On Thu, 15 Sep 2005 19:15:06 GMT, "Micke Nilsson" <na...@home.se>
wrote:

Doesn't look like much of a double to me.

(After I took I'd probably lose a gammon, and when that
happened I'd accuse my opponent of cheating. But given
various themes around here we should note that my accusation
of cheating would just be a little joke - in the
local chouette we always accuse the opponent of cheating
when he doubles in a borderline position and then
wins big...)

************************

David C. Ullrich

[paulde...@att.net]

No double in my opinion but I don't think X should beaver. I heard an
adage that it's dangerous to double when you only have a 1 point board,
and I think it applies here.

As O, I would not even consider doubling.

Paul Epstein

[Grunty]

Yes, I knew I'd be alone against the world in this one...

[Philippe Michel]

Le 16-09-2005, Grunty <grunti...@yahoo.com> a écrit :

> The bad thing for X is his lack of an anchor; should he had one,
> *anywhere* from 24 to 20 point, this would be no-double.
>
> Paradoxically, I consider the fact both checkers being advanced, more
> of a crucial disadvantage than a dynamic factor. They just offer more
> targets, and the only solid argument inviting for a double. Should
> *one* of them stands on the 24 or perhaps even on the 23 point, would
> shift my evaluation to no-double, since the enhanced board coverage
> would prevent O from playing safe non-pointing rolls behind them.

It looks like the fact that both back men are advanced is not significant
after all. A gnubg rollout (assuming the game started with 5-3 6-6 3-2)
gave :

24/22 13/10 best
24/22 24/21 inferior by 0.04
24/21 13/11 inferior by 0.04
24/21 6/4 inferior by 0.05
13/10 6/4 inferior by 0.07
13/10/8 inferior by 0.09
(truncated cubeful rollout, standard deviations slightly higher than 0.01)

It's not obvious to me why 24/22 13/10 stands a little out (duplication of
3s ?), but the others splits, including advancing both men, are equal.

[Micke Nilsson]

3-ply "Instant evaluation"

Money session. Score X-O: 0-0

O on roll, cube action
+-1--2--3--4--5--6--------7--8--9-10-11-12-+
| X X O | | O O X |
| O | | O O X |
| O | | O X | S
| O | | X | n
| O | | X | o
| |BAR| | w
| | | | i
| X | | | e
| X | | O |
| X X | | O X O |
| X X | | O X O |
+24-23-22-21-20-19-------18-17-16-15-14-13-+
Pipcount X: 154 O: 143 X-O: 0-0/Money (1)
CubeValue: 1

3-Ply Money equity: 0,355
0,7% 17,6% 62,5% 37,5% 7,6% 0,2%
1. No double 0,500
2. Double, take 0,436 (-0,064)
3. Double, pass 1,000 (+0,500)
Proper cube action: No double, take 11%

------------------------------ End ----------------------------------

3-ply Rollout:

Money session. Score X-O: 0-0

O on roll, cube action
+-1--2--3--4--5--6--------7--8--9-10-11-12-+
| X X O | | O O X |
| O | | O O X |
| O | | O X | S
| O | | X | n
| O | | X | o
| |BAR| | w
| | | | i
| X | | | e
| X | | O |
| X X | | O X O |
| X X | | O X O |
+24-23-22-21-20-19-------18-17-16-15-14-13-+
Pipcount X: 154 O: 143 X-O: 0-0/Money (1)
CubeValue: 1

Rollout Money equity: 0,364
0,5% 17,9% 62,9% 37,1% 7,6% 0,2%
95% confidence interval:
- money cubeless eq.: 0,364 ą0,022,
- live cube no double: 0,556 ą0,043,
- live cube double take: 0,477 ą0,060.
Rollout settings:
Full rollout,
324 games (equiv. 10227 games),
played 3-ply (standard), cube 3-ply,
settlement 0,550 at 16 pts,
seed 1, without race database.
Evaluations
1. No double 0,513
2. Double, take 0,456 (-0,057)
3. Double, pass 1,000 (+0,487)
Proper cube action: No double, take 10%
Live cube
1. No double 0,556
2. Double, take 0,477 (-0,079)
3. Double, pass 1,000 (+0,444)
Proper cube action: No double, take 15%

------------------------------ End ----------------------------------